Imaging

SAN FRANCISCO — With computed tomography angiography, “patients literally go home with a Band-Aid and a bottle of water” after just 20 minutes, Matthew J. Budoff, M.D., remarked at a cardiovascular imaging conference sponsored by the American College of Cardiology.

With high sensitivity and specificity and images that rival the resolution obtainable with traditional coronary angiography from the catheterization lab, CT angiography will allow many more patients to avoid an invasive procedure, said Dr. Budoff of Harbor-UCLA Medical Center, Torrance, Calif.

After an injection of 80–100 mL of nonionic iodinated contrast solution, up to 4,000 two-dimensional images can be obtained within 20–30 seconds as the patient holds his or her breath. The entire procedure takes 20 minutes, and interpretation takes another 10 minutes.

Sophisticated workstations assemble the stack of 2D images into a three-dimensional reconstruction. Interpretations are made on the basis of the 3D reconstruction with reference to the 2D images.

Dr. Budoff started working with CT angiography in the mid-1990s. In those days it took 3 weeks of full-time computation to assemble a single 3D reconstruction. This same function takes just 30 seconds today.

And these workstations allow the cardiologist to rotate the heart image in three dimensions, to zoom in to interesting features, and to easily reference the original 2D data from any point of interest.

The initial studies of four-slice CT angiography revealed the limitations of this early technique. Only 30% of patients had all three major arteries available for analysis, and in detecting stenosis the sensitivity was just 58% with 76% specificity.

Now, as 16-slice and even 64-slice CT angiography become available, the sensitivity and specificity have improved considerably. Studies have calculated sensitivities as high as 97% and specificities as high as 94%.

Most important, the negative predictive value is 98%–100%. “The benefit of CT angio is that when the coronaries look normal, the coronaries are normal,” Dr. Budoff said.

The temporal resolution of the CT images is about 175 milliseconds, so reducing the heart rate to below 60 beats per minute is important for accuracy and interpretability. Most centers use 100 mg metoprolol 1 hour prior to the study and/or a 5-mg intravenous metoprolol push every 5 minutes until the patient achieves a slow heart rate.

A regular rhythm is also important. With multiple detectors obtaining images at specific parts of the heart cycle, the modality reaches an effective frame speed of 15 images per second. This is slower than the cath lab, but fast enough that the images are free of motion artifact.

CT angiography may be the best technique for imaging the results of bypass grafting as the anastomoses are clearly visible. Other clinical indications for CT angiography are in cases of equivocal results following stress testing; to evaluate patency post angioplasty, post stent, and post bypass surgery; in cases of congenital abnormalities and anomalous coronaries; before and after atrial fibrillation ablation; and before placing a biventricular pacer.

CT angiography is not without its disadvantages, however. It's not very good for visualizing vessels with diameters less than 1.5 mm. It is subject to artifacts from extensive calcification, stents, or extensive clips after bypass grafting. And it subjects patients to a relatively high dose of radiation—about 9.3–11.3 mSv, compared with 2.1–2.3 mSv for the cath lab and 0.1 mSv for a chest x-ray.

CT angiography reveales high-grade stenosis (dark area) in the mid-left anterior descending coronary artery. Courtesy Dr. Matthew J. Budoff

SAN FRANCISCO — With computed tomography angiography, “patients literally go home with a Band-Aid and a bottle of water” after just 20 minutes, Matthew J. Budoff, M.D., remarked at a cardiovascular imaging conference sponsored by the American College of Cardiology.

With high sensitivity and specificity and images that rival the resolution obtainable with traditional coronary angiography from the catheterization lab, CT angiography will allow many more patients to avoid an invasive procedure, said Dr. Budoff of Harbor-UCLA Medical Center, Torrance, Calif.

After an injection of 80–100 mL of nonionic iodinated contrast solution, up to 4,000 two-dimensional images can be obtained within 20–30 seconds as the patient holds his or her breath. The entire procedure takes 20 minutes, and interpretation takes another 10 minutes.

Sophisticated workstations assemble the stack of 2D images into a three-dimensional reconstruction. Interpretations are made on the basis of the 3D reconstruction with reference to the 2D images.

Dr. Budoff started working with CT angiography in the mid-1990s. In those days it took 3 weeks of full-time computation to assemble a single 3D reconstruction. This same function takes just 30 seconds today.

And these workstations allow the cardiologist to rotate the heart image in three dimensions, to zoom in to interesting features, and to easily reference the original 2D data from any point of interest.

The initial studies of four-slice CT angiography revealed the limitations of this early technique. Only 30% of patients had all three major arteries available for analysis, and in detecting stenosis the sensitivity was just 58% with 76% specificity.

Now, as 16-slice and even 64-slice CT angiography become available, the sensitivity and specificity have improved considerably. Studies have calculated sensitivities as high as 97% and specificities as high as 94%.

Most important, the negative predictive value is 98%–100%. “The benefit of CT angio is that when the coronaries look normal, the coronaries are normal,” Dr. Budoff said.

The temporal resolution of the CT images is about 175 milliseconds, so reducing the heart rate to below 60 beats per minute is important for accuracy and interpretability. Most centers use 100 mg metoprolol 1 hour prior to the study and/or a 5-mg intravenous metoprolol push every 5 minutes until the patient achieves a slow heart rate.

A regular rhythm is also important. With multiple detectors obtaining images at specific parts of the heart cycle, the modality reaches an effective frame speed of 15 images per second. This is slower than the cath lab, but fast enough that the images are free of motion artifact.

CT angiography may be the best technique for imaging the results of bypass grafting as the anastomoses are clearly visible. Other clinical indications for CT angiography are in cases of equivocal results following stress testing; to evaluate patency post angioplasty, post stent, and post bypass surgery; in cases of congenital abnormalities and anomalous coronaries; before and after atrial fibrillation ablation; and before placing a biventricular pacer.

CT angiography is not without its disadvantages, however. It's not very good for visualizing vessels with diameters less than 1.5 mm. It is subject to artifacts from extensive calcification, stents, or extensive clips after bypass grafting. And it subjects patients to a relatively high dose of radiation—about 9.3–11.3 mSv, compared with 2.1–2.3 mSv for the cath lab and 0.1 mSv for a chest x-ray.

CT angiography reveales high-grade stenosis (dark area) in the mid-left anterior descending coronary artery. Courtesy Dr. Matthew J. Budoff

SAN FRANCISCO — With computed tomography angiography, “patients literally go home with a Band-Aid and a bottle of water” after just 20 minutes, Matthew J. Budoff, M.D., remarked at a cardiovascular imaging conference sponsored by the American College of Cardiology.

With high sensitivity and specificity and images that rival the resolution obtainable with traditional coronary angiography from the catheterization lab, CT angiography will allow many more patients to avoid an invasive procedure, said Dr. Budoff of Harbor-UCLA Medical Center, Torrance, Calif.

After an injection of 80–100 mL of nonionic iodinated contrast solution, up to 4,000 two-dimensional images can be obtained within 20–30 seconds as the patient holds his or her breath. The entire procedure takes 20 minutes, and interpretation takes another 10 minutes.

Sophisticated workstations assemble the stack of 2D images into a three-dimensional reconstruction. Interpretations are made on the basis of the 3D reconstruction with reference to the 2D images.

Dr. Budoff started working with CT angiography in the mid-1990s. In those days it took 3 weeks of full-time computation to assemble a single 3D reconstruction. This same function takes just 30 seconds today.

And these workstations allow the cardiologist to rotate the heart image in three dimensions, to zoom in to interesting features, and to easily reference the original 2D data from any point of interest.

The initial studies of four-slice CT angiography revealed the limitations of this early technique. Only 30% of patients had all three major arteries available for analysis, and in detecting stenosis the sensitivity was just 58% with 76% specificity.

Now, as 16-slice and even 64-slice CT angiography become available, the sensitivity and specificity have improved considerably. Studies have calculated sensitivities as high as 97% and specificities as high as 94%.

Most important, the negative predictive value is 98%–100%. “The benefit of CT angio is that when the coronaries look normal, the coronaries are normal,” Dr. Budoff said.

The temporal resolution of the CT images is about 175 milliseconds, so reducing the heart rate to below 60 beats per minute is important for accuracy and interpretability. Most centers use 100 mg metoprolol 1 hour prior to the study and/or a 5-mg intravenous metoprolol push every 5 minutes until the patient achieves a slow heart rate.

A regular rhythm is also important. With multiple detectors obtaining images at specific parts of the heart cycle, the modality reaches an effective frame speed of 15 images per second. This is slower than the cath lab, but fast enough that the images are free of motion artifact.

CT angiography may be the best technique for imaging the results of bypass grafting as the anastomoses are clearly visible. Other clinical indications for CT angiography are in cases of equivocal results following stress testing; to evaluate patency post angioplasty, post stent, and post bypass surgery; in cases of congenital abnormalities and anomalous coronaries; before and after atrial fibrillation ablation; and before placing a biventricular pacer.

CT angiography is not without its disadvantages, however. It's not very good for visualizing vessels with diameters less than 1.5 mm. It is subject to artifacts from extensive calcification, stents, or extensive clips after bypass grafting. And it subjects patients to a relatively high dose of radiation—about 9.3–11.3 mSv, compared with 2.1–2.3 mSv for the cath lab and 0.1 mSv for a chest x-ray.

CT angiography reveales high-grade stenosis (dark area) in the mid-left anterior descending coronary artery. Courtesy Dr. Matthew J. Budoff

Reports of comas and other serious injuries in people with implanted neurologic stimulators incurred during MRI procedures have spurred the Food and Drug Administration to issue a reminder about these risks.

The agency has received “several” reports of coma, permanent neurologic impairment, and other serious injuries in patients who had deep brain stimulators and vagus nerve stimulators in place when they underwent MRI. “Similar injuries could be caused by any type of implanted neurologic stimulator,” such as spinal cord, peripheral nerve, and neuromuscular stimulators, according to the warning, issued by the FDA's Center for Devices and Radiological Health.

These injuries probably result when the electrodes at the end of the lead wires heat up, injuring the surrounding tissue, the statement said.

The FDA is recommending that physicians who implant or monitor neurologic stimulators explain to patients about MRI procedures, and stress that they must ask their monitoring physician, before having any MRI, whether it can be performed safely.

The notification includes a list of recommendations for radiologists and health care professionals who use MRI equipment. They include consulting with the referring physician and either reviewing the label or contacting the manufacturer of the specific model of implanted neurologic stimulator to learn the types and/or strengths of MRI equipment tested for the interaction with the device.

The notification also advises that patients be carefully screened for implanted devices before MRI procedures are performed, even if the device has been turned off, and should be asked about devices that have been removed, since some leads or portions of leads can remain in the body after removal and “may act as an antenna and become heated” during the MRI exam.

Reports of comas and other serious injuries in people with implanted neurologic stimulators incurred during MRI procedures have spurred the Food and Drug Administration to issue a reminder about these risks.

The agency has received “several” reports of coma, permanent neurologic impairment, and other serious injuries in patients who had deep brain stimulators and vagus nerve stimulators in place when they underwent MRI. “Similar injuries could be caused by any type of implanted neurologic stimulator,” such as spinal cord, peripheral nerve, and neuromuscular stimulators, according to the warning, issued by the FDA's Center for Devices and Radiological Health.

These injuries probably result when the electrodes at the end of the lead wires heat up, injuring the surrounding tissue, the statement said.

The FDA is recommending that physicians who implant or monitor neurologic stimulators explain to patients about MRI procedures, and stress that they must ask their monitoring physician, before having any MRI, whether it can be performed safely.

The notification includes a list of recommendations for radiologists and health care professionals who use MRI equipment. They include consulting with the referring physician and either reviewing the label or contacting the manufacturer of the specific model of implanted neurologic stimulator to learn the types and/or strengths of MRI equipment tested for the interaction with the device.

The notification also advises that patients be carefully screened for implanted devices before MRI procedures are performed, even if the device has been turned off, and should be asked about devices that have been removed, since some leads or portions of leads can remain in the body after removal and “may act as an antenna and become heated” during the MRI exam.

Reports of comas and other serious injuries in people with implanted neurologic stimulators incurred during MRI procedures have spurred the Food and Drug Administration to issue a reminder about these risks.

The agency has received “several” reports of coma, permanent neurologic impairment, and other serious injuries in patients who had deep brain stimulators and vagus nerve stimulators in place when they underwent MRI. “Similar injuries could be caused by any type of implanted neurologic stimulator,” such as spinal cord, peripheral nerve, and neuromuscular stimulators, according to the warning, issued by the FDA's Center for Devices and Radiological Health.

These injuries probably result when the electrodes at the end of the lead wires heat up, injuring the surrounding tissue, the statement said.

The FDA is recommending that physicians who implant or monitor neurologic stimulators explain to patients about MRI procedures, and stress that they must ask their monitoring physician, before having any MRI, whether it can be performed safely.

The notification includes a list of recommendations for radiologists and health care professionals who use MRI equipment. They include consulting with the referring physician and either reviewing the label or contacting the manufacturer of the specific model of implanted neurologic stimulator to learn the types and/or strengths of MRI equipment tested for the interaction with the device.

The notification also advises that patients be carefully screened for implanted devices before MRI procedures are performed, even if the device has been turned off, and should be asked about devices that have been removed, since some leads or portions of leads can remain in the body after removal and “may act as an antenna and become heated” during the MRI exam.

BOSTON — Left atrial function is a sensitive predictor of cardiovascular outcome in patients with stable coronary heart disease, a prospective study has shown.

Of 989 patients with heart disease recruited for the ongoing Heart and Soul Study at the San Francisco Veterans' Affairs Medical Center and the University of California at San Francisco, 8.5% of the 247 patients whose left atrial function index was in the lowest quartile had a cardiac event during the 1-year follow-up period, compared with 4% of the 742 whose indices fell into the upper three quartiles, as reported Pamela Y.F. Hsu, M.D., in a poster presentation at the annual meeting of the American Society of Echocardiography.

“The association between a low index and cardiovascular outcomes persisted after adjusting for smoking, congestive heart failure, other comorbid illnesses, medication use, and left ventricular ejection fraction,” said Dr. Hsu of the Mayo Clinic in Scottsdale, Ariz.

To determine the left atrial function index (LAFI), the investigators calculated the time-velocity integral for the left ventricular outflow tract, the left atrial end systolic volume (LAESV) and end diastolic volume (LAEDV), and the LAESV index measurements by using transthoracic echocardiography.

They also measured biplane left atrial volumes and calculated the left atrial ejection fraction (LAESV/LAEDV). The LAFI represents the left ventricular outflow tract time-velocity integral multiplied by the left atrial ejection fraction over the LAESV index, with the whole multiplied by 10 log 4. Using logistic regression, the investigators evaluated the association between the lowest LAFI quartile and cardiovascular outcomes—including myocardial infarction, hospitalization for congestive heart failure, and coronary disease death—and adjusted for potential confounding variables.

In the lowest quartile, the age-adjusted odds ratio for having any cardiac event within 1 year was 3.3, while the specific odds ratios for myocardial infarction, heart failure, and coronary disease death were 3.3, 4.8, and 4.2, respectively.

In the multivariable adjusted model, the odds ratio for any cardiac event was 2.6 and the respective odds ratios for myocardial infarction, heart failure, and coronary disease death were 3.0, 3.3, and 2.2. All of the associations were statistically significant, Dr. Hsu said.

The findings indicate that the LAFI “is a simple, powerful, and clinically useful tool” for predicting 1-year cardiovascular outcomes in coronary heart disease patients, said Dr. Hsu.

BOSTON — Left atrial function is a sensitive predictor of cardiovascular outcome in patients with stable coronary heart disease, a prospective study has shown.

Of 989 patients with heart disease recruited for the ongoing Heart and Soul Study at the San Francisco Veterans' Affairs Medical Center and the University of California at San Francisco, 8.5% of the 247 patients whose left atrial function index was in the lowest quartile had a cardiac event during the 1-year follow-up period, compared with 4% of the 742 whose indices fell into the upper three quartiles, as reported Pamela Y.F. Hsu, M.D., in a poster presentation at the annual meeting of the American Society of Echocardiography.

“The association between a low index and cardiovascular outcomes persisted after adjusting for smoking, congestive heart failure, other comorbid illnesses, medication use, and left ventricular ejection fraction,” said Dr. Hsu of the Mayo Clinic in Scottsdale, Ariz.

To determine the left atrial function index (LAFI), the investigators calculated the time-velocity integral for the left ventricular outflow tract, the left atrial end systolic volume (LAESV) and end diastolic volume (LAEDV), and the LAESV index measurements by using transthoracic echocardiography.

They also measured biplane left atrial volumes and calculated the left atrial ejection fraction (LAESV/LAEDV). The LAFI represents the left ventricular outflow tract time-velocity integral multiplied by the left atrial ejection fraction over the LAESV index, with the whole multiplied by 10 log 4. Using logistic regression, the investigators evaluated the association between the lowest LAFI quartile and cardiovascular outcomes—including myocardial infarction, hospitalization for congestive heart failure, and coronary disease death—and adjusted for potential confounding variables.

In the lowest quartile, the age-adjusted odds ratio for having any cardiac event within 1 year was 3.3, while the specific odds ratios for myocardial infarction, heart failure, and coronary disease death were 3.3, 4.8, and 4.2, respectively.

In the multivariable adjusted model, the odds ratio for any cardiac event was 2.6 and the respective odds ratios for myocardial infarction, heart failure, and coronary disease death were 3.0, 3.3, and 2.2. All of the associations were statistically significant, Dr. Hsu said.

The findings indicate that the LAFI “is a simple, powerful, and clinically useful tool” for predicting 1-year cardiovascular outcomes in coronary heart disease patients, said Dr. Hsu.

BOSTON — Left atrial function is a sensitive predictor of cardiovascular outcome in patients with stable coronary heart disease, a prospective study has shown.

Of 989 patients with heart disease recruited for the ongoing Heart and Soul Study at the San Francisco Veterans' Affairs Medical Center and the University of California at San Francisco, 8.5% of the 247 patients whose left atrial function index was in the lowest quartile had a cardiac event during the 1-year follow-up period, compared with 4% of the 742 whose indices fell into the upper three quartiles, as reported Pamela Y.F. Hsu, M.D., in a poster presentation at the annual meeting of the American Society of Echocardiography.

“The association between a low index and cardiovascular outcomes persisted after adjusting for smoking, congestive heart failure, other comorbid illnesses, medication use, and left ventricular ejection fraction,” said Dr. Hsu of the Mayo Clinic in Scottsdale, Ariz.

To determine the left atrial function index (LAFI), the investigators calculated the time-velocity integral for the left ventricular outflow tract, the left atrial end systolic volume (LAESV) and end diastolic volume (LAEDV), and the LAESV index measurements by using transthoracic echocardiography.

They also measured biplane left atrial volumes and calculated the left atrial ejection fraction (LAESV/LAEDV). The LAFI represents the left ventricular outflow tract time-velocity integral multiplied by the left atrial ejection fraction over the LAESV index, with the whole multiplied by 10 log 4. Using logistic regression, the investigators evaluated the association between the lowest LAFI quartile and cardiovascular outcomes—including myocardial infarction, hospitalization for congestive heart failure, and coronary disease death—and adjusted for potential confounding variables.

In the lowest quartile, the age-adjusted odds ratio for having any cardiac event within 1 year was 3.3, while the specific odds ratios for myocardial infarction, heart failure, and coronary disease death were 3.3, 4.8, and 4.2, respectively.

In the multivariable adjusted model, the odds ratio for any cardiac event was 2.6 and the respective odds ratios for myocardial infarction, heart failure, and coronary disease death were 3.0, 3.3, and 2.2. All of the associations were statistically significant, Dr. Hsu said.

The findings indicate that the LAFI “is a simple, powerful, and clinically useful tool” for predicting 1-year cardiovascular outcomes in coronary heart disease patients, said Dr. Hsu.

BOSTON — A novel risk score, comprising measures of wall motion and myocardial perfusion from contrast echocardiography and clinical variables, is a sensitive predictor of 1-year outcome in patients presenting to the emergency department with chest pain prior to obtaining troponin data, reported William Foster, M.D.

In the risk score development model and a subsequent validation model, the tool proved to be more effective for risk stratification than did the use of cardiac troponin measures and clinical variables without the ultrasound data, said Dr. Foster in a poster presentation at the annual meeting of the American Society of Echocardiography.

Dr. Foster and colleagues at the University of Virginia in Charlottesville developed the risk score using clinical and myocardial imaging data from 973 patients presenting to the emergency department (ED) with chest pain that could not easily be attributed to a noncardiac cause and who did not have ST-segment elevation on their admission ECG.

The risk score stratifies the likelihood of developing primary or secondary events within 1 year of chest pain presentation in the ED. Primary events include all cause mortality and myocardial infarction; secondary events include unstable angina, revascularization, and heart failure.

The clinical predictive factors considered in the risk score include age older than 60 years, the presence of three or more coronary disease risk factors, known coronary luminal diameter narrowing of more than 50%, ST-segment deviation on electrocardiogram, two or more angina events in the previous 24 hours, and aspirin use in the previous 7 days. (See box.)

With respect to echocardiographic variables for risk prediction, regional function was characterized as normal or abnormal using a 14-segment model, including 6 segments in each of the basal and midpapillary muscle levels and 2 segments in the apex. Myocardial perfusion was evaluated using the same segmented model and was deemed abnormal if there was no evidence of maximal opacification within a segment by five cardiac cycles. An echocardiographic study was considered abnormal if at least one segment was abnormal for either regional function or myocardial perfusion, Dr. Foster noted.

Each of these predictors is associated with a score between 0 and 100, based on estimates developed using logistic regression models. “The total risk score is the sum of all of these scores,” said Dr. Foster.

Among the 973 patients in the development sample, the model showed “excellent discriminatory capacity,” with an 86% probability of correct prediction, said Dr. Foster. Approximately 60% of those with total risk scores of 200 or higher, and 30% of those with scores of 150–199, experienced a primary or secondary cardiac event at 1 year. About 17% of patients with scores of 100–149, 7% of those with scores of 50–99, and 4% of those with scores of 0–49 had events within 1 year.

To validate the sensitivity of the scores as potential prognostic indicators, the investigators applied the risk score model prospectively in 232 patients who were followed for up to 1 year.

“We saw the same pattern in the validation sample, with a similar prognostic discriminatory capacity between the validation and development samples,” said Dr. Foster. In fact, the discriminatory capacity of the risk score “was greater than clinical variables plus serum cardiac troponin,” he said.

The ability to formulate prognoses prior to obtaining troponin data could streamline the management of chest pain patients in the ED, Dr. Foster concluded.

In this contrast-enhanced image from the apical four-chamber view, arrows show a resting perfusion defect in the mid- and distal septum of a patient with chest pain. Courtesy Dr. Kevin S. Wei

BOSTON — A novel risk score, comprising measures of wall motion and myocardial perfusion from contrast echocardiography and clinical variables, is a sensitive predictor of 1-year outcome in patients presenting to the emergency department with chest pain prior to obtaining troponin data, reported William Foster, M.D.

In the risk score development model and a subsequent validation model, the tool proved to be more effective for risk stratification than did the use of cardiac troponin measures and clinical variables without the ultrasound data, said Dr. Foster in a poster presentation at the annual meeting of the American Society of Echocardiography.

Dr. Foster and colleagues at the University of Virginia in Charlottesville developed the risk score using clinical and myocardial imaging data from 973 patients presenting to the emergency department (ED) with chest pain that could not easily be attributed to a noncardiac cause and who did not have ST-segment elevation on their admission ECG.

The risk score stratifies the likelihood of developing primary or secondary events within 1 year of chest pain presentation in the ED. Primary events include all cause mortality and myocardial infarction; secondary events include unstable angina, revascularization, and heart failure.

The clinical predictive factors considered in the risk score include age older than 60 years, the presence of three or more coronary disease risk factors, known coronary luminal diameter narrowing of more than 50%, ST-segment deviation on electrocardiogram, two or more angina events in the previous 24 hours, and aspirin use in the previous 7 days. (See box.)

With respect to echocardiographic variables for risk prediction, regional function was characterized as normal or abnormal using a 14-segment model, including 6 segments in each of the basal and midpapillary muscle levels and 2 segments in the apex. Myocardial perfusion was evaluated using the same segmented model and was deemed abnormal if there was no evidence of maximal opacification within a segment by five cardiac cycles. An echocardiographic study was considered abnormal if at least one segment was abnormal for either regional function or myocardial perfusion, Dr. Foster noted.

Each of these predictors is associated with a score between 0 and 100, based on estimates developed using logistic regression models. “The total risk score is the sum of all of these scores,” said Dr. Foster.

Among the 973 patients in the development sample, the model showed “excellent discriminatory capacity,” with an 86% probability of correct prediction, said Dr. Foster. Approximately 60% of those with total risk scores of 200 or higher, and 30% of those with scores of 150–199, experienced a primary or secondary cardiac event at 1 year. About 17% of patients with scores of 100–149, 7% of those with scores of 50–99, and 4% of those with scores of 0–49 had events within 1 year.

To validate the sensitivity of the scores as potential prognostic indicators, the investigators applied the risk score model prospectively in 232 patients who were followed for up to 1 year.

“We saw the same pattern in the validation sample, with a similar prognostic discriminatory capacity between the validation and development samples,” said Dr. Foster. In fact, the discriminatory capacity of the risk score “was greater than clinical variables plus serum cardiac troponin,” he said.

The ability to formulate prognoses prior to obtaining troponin data could streamline the management of chest pain patients in the ED, Dr. Foster concluded.

In this contrast-enhanced image from the apical four-chamber view, arrows show a resting perfusion defect in the mid- and distal septum of a patient with chest pain. Courtesy Dr. Kevin S. Wei

BOSTON — A novel risk score, comprising measures of wall motion and myocardial perfusion from contrast echocardiography and clinical variables, is a sensitive predictor of 1-year outcome in patients presenting to the emergency department with chest pain prior to obtaining troponin data, reported William Foster, M.D.

In the risk score development model and a subsequent validation model, the tool proved to be more effective for risk stratification than did the use of cardiac troponin measures and clinical variables without the ultrasound data, said Dr. Foster in a poster presentation at the annual meeting of the American Society of Echocardiography.

Dr. Foster and colleagues at the University of Virginia in Charlottesville developed the risk score using clinical and myocardial imaging data from 973 patients presenting to the emergency department (ED) with chest pain that could not easily be attributed to a noncardiac cause and who did not have ST-segment elevation on their admission ECG.

The risk score stratifies the likelihood of developing primary or secondary events within 1 year of chest pain presentation in the ED. Primary events include all cause mortality and myocardial infarction; secondary events include unstable angina, revascularization, and heart failure.

The clinical predictive factors considered in the risk score include age older than 60 years, the presence of three or more coronary disease risk factors, known coronary luminal diameter narrowing of more than 50%, ST-segment deviation on electrocardiogram, two or more angina events in the previous 24 hours, and aspirin use in the previous 7 days. (See box.)

With respect to echocardiographic variables for risk prediction, regional function was characterized as normal or abnormal using a 14-segment model, including 6 segments in each of the basal and midpapillary muscle levels and 2 segments in the apex. Myocardial perfusion was evaluated using the same segmented model and was deemed abnormal if there was no evidence of maximal opacification within a segment by five cardiac cycles. An echocardiographic study was considered abnormal if at least one segment was abnormal for either regional function or myocardial perfusion, Dr. Foster noted.

Each of these predictors is associated with a score between 0 and 100, based on estimates developed using logistic regression models. “The total risk score is the sum of all of these scores,” said Dr. Foster.

Among the 973 patients in the development sample, the model showed “excellent discriminatory capacity,” with an 86% probability of correct prediction, said Dr. Foster. Approximately 60% of those with total risk scores of 200 or higher, and 30% of those with scores of 150–199, experienced a primary or secondary cardiac event at 1 year. About 17% of patients with scores of 100–149, 7% of those with scores of 50–99, and 4% of those with scores of 0–49 had events within 1 year.

To validate the sensitivity of the scores as potential prognostic indicators, the investigators applied the risk score model prospectively in 232 patients who were followed for up to 1 year.

“We saw the same pattern in the validation sample, with a similar prognostic discriminatory capacity between the validation and development samples,” said Dr. Foster. In fact, the discriminatory capacity of the risk score “was greater than clinical variables plus serum cardiac troponin,” he said.

The ability to formulate prognoses prior to obtaining troponin data could streamline the management of chest pain patients in the ED, Dr. Foster concluded.

In this contrast-enhanced image from the apical four-chamber view, arrows show a resting perfusion defect in the mid- and distal septum of a patient with chest pain. Courtesy Dr. Kevin S. Wei

LOS ANGELES — High-risk findings on myocardial perfusion studies require an immediate telephone call from a nuclear cardiologist to the referring physician, even when the temptation is to perform more tests to clarify the extent of cardiac viability, said Robert C. Hendel, M.D., at a meeting sponsored by the American College of Cardiology.

Dr. Hendel presented the case of a 31-year-old man, 6' 4” tall, 244 pounds, who presented with exertional chest pain. He had a history of radiation therapy for Hodgkin's disease. During cardiac function tests, the patient was only able to proceed 4.5 minutes on the Bruce protocol before he experienced chest pain with ST-segment changes lasting about 15 minutes.

The patient's nuclear single-photon emission computed tomography (SPECT) images showed significant ischemia and large regions of decreased perfusion.

Yet, in the interaction session attended by nuclear cardiologists, just over half of audience members voted that they would respond by immediately calling the referring physician. Other attendees split their votes among other options, including repeating the SPECT using pharmacologic stress, performing additional imaging to assess viability, or reporting the likelihood of single-vessel disease.

Clearly, those in attendance were influenced by the patient's young age and the fact that more studies might provide more precise information. However, the study's findings, combined with the patient's response to the cardiac function test, should be enough to warrant an immediate consultation with the referring physician, said Dr. Hendel at the meeting, cosponsored by the American Society of Nuclear Cardiology and Cedars-Sinai Medical Center.

“This is a very high-risk study,” he said. “Our responsibility is to pick up the phone and communicate that kind of information.”

In the case he presented, consultation with the referring cardiologist led to a referral to coronary angiography. The patient was found to have extensive coronary artery disease, including high-grade narrows (greater than 95%) in the proximal left anterior descending coronary artery involving the bifurcation of a large first diagonal branch. “This high-risk anatomy was unsuitable for percutaneous coronary intervention, and he was referred for bypass surgery,” said Dr. Hendel following the meeting.

One week after his SPECT study, the patient underwent five-vessel bypass graft surgery. “He is doing well now, without symptoms.”

Dr. Hendel, a former president of the American Society of Nuclear Cardiology who practices in Fox River Grove, Ill., said he was familiar with two lawsuits in the past 5 years in which both the nuclear cardiologist and internist were sued owing to a lack of timely notification of a high-risk finding.

LOS ANGELES — High-risk findings on myocardial perfusion studies require an immediate telephone call from a nuclear cardiologist to the referring physician, even when the temptation is to perform more tests to clarify the extent of cardiac viability, said Robert C. Hendel, M.D., at a meeting sponsored by the American College of Cardiology.

Dr. Hendel presented the case of a 31-year-old man, 6' 4” tall, 244 pounds, who presented with exertional chest pain. He had a history of radiation therapy for Hodgkin's disease. During cardiac function tests, the patient was only able to proceed 4.5 minutes on the Bruce protocol before he experienced chest pain with ST-segment changes lasting about 15 minutes.

The patient's nuclear single-photon emission computed tomography (SPECT) images showed significant ischemia and large regions of decreased perfusion.

Yet, in the interaction session attended by nuclear cardiologists, just over half of audience members voted that they would respond by immediately calling the referring physician. Other attendees split their votes among other options, including repeating the SPECT using pharmacologic stress, performing additional imaging to assess viability, or reporting the likelihood of single-vessel disease.

Clearly, those in attendance were influenced by the patient's young age and the fact that more studies might provide more precise information. However, the study's findings, combined with the patient's response to the cardiac function test, should be enough to warrant an immediate consultation with the referring physician, said Dr. Hendel at the meeting, cosponsored by the American Society of Nuclear Cardiology and Cedars-Sinai Medical Center.

“This is a very high-risk study,” he said. “Our responsibility is to pick up the phone and communicate that kind of information.”

In the case he presented, consultation with the referring cardiologist led to a referral to coronary angiography. The patient was found to have extensive coronary artery disease, including high-grade narrows (greater than 95%) in the proximal left anterior descending coronary artery involving the bifurcation of a large first diagonal branch. “This high-risk anatomy was unsuitable for percutaneous coronary intervention, and he was referred for bypass surgery,” said Dr. Hendel following the meeting.

One week after his SPECT study, the patient underwent five-vessel bypass graft surgery. “He is doing well now, without symptoms.”

Dr. Hendel, a former president of the American Society of Nuclear Cardiology who practices in Fox River Grove, Ill., said he was familiar with two lawsuits in the past 5 years in which both the nuclear cardiologist and internist were sued owing to a lack of timely notification of a high-risk finding.

LOS ANGELES — High-risk findings on myocardial perfusion studies require an immediate telephone call from a nuclear cardiologist to the referring physician, even when the temptation is to perform more tests to clarify the extent of cardiac viability, said Robert C. Hendel, M.D., at a meeting sponsored by the American College of Cardiology.

Dr. Hendel presented the case of a 31-year-old man, 6' 4” tall, 244 pounds, who presented with exertional chest pain. He had a history of radiation therapy for Hodgkin's disease. During cardiac function tests, the patient was only able to proceed 4.5 minutes on the Bruce protocol before he experienced chest pain with ST-segment changes lasting about 15 minutes.

The patient's nuclear single-photon emission computed tomography (SPECT) images showed significant ischemia and large regions of decreased perfusion.

Yet, in the interaction session attended by nuclear cardiologists, just over half of audience members voted that they would respond by immediately calling the referring physician. Other attendees split their votes among other options, including repeating the SPECT using pharmacologic stress, performing additional imaging to assess viability, or reporting the likelihood of single-vessel disease.

Clearly, those in attendance were influenced by the patient's young age and the fact that more studies might provide more precise information. However, the study's findings, combined with the patient's response to the cardiac function test, should be enough to warrant an immediate consultation with the referring physician, said Dr. Hendel at the meeting, cosponsored by the American Society of Nuclear Cardiology and Cedars-Sinai Medical Center.

“This is a very high-risk study,” he said. “Our responsibility is to pick up the phone and communicate that kind of information.”

In the case he presented, consultation with the referring cardiologist led to a referral to coronary angiography. The patient was found to have extensive coronary artery disease, including high-grade narrows (greater than 95%) in the proximal left anterior descending coronary artery involving the bifurcation of a large first diagonal branch. “This high-risk anatomy was unsuitable for percutaneous coronary intervention, and he was referred for bypass surgery,” said Dr. Hendel following the meeting.

One week after his SPECT study, the patient underwent five-vessel bypass graft surgery. “He is doing well now, without symptoms.”

Dr. Hendel, a former president of the American Society of Nuclear Cardiology who practices in Fox River Grove, Ill., said he was familiar with two lawsuits in the past 5 years in which both the nuclear cardiologist and internist were sued owing to a lack of timely notification of a high-risk finding.

PONTE VEDRA BEACH, FLA. — An 11-point risk-scoring system can stratify the risk that patients face from contrast-induced nephropathy, on the basis of a validation study that involved more than 3,000 patients.

Applying the risk score in routine practice could identify at-risk patients who should receive a limited amount of contrast during angiography or a percutaneous coronary intervention. It could also identify patients who should receive more intensive prophylaxis, with 12 hours of intravenous hydration with normal saline before having radio-contrast, Kimberly A. Skelding, M.D., said at the annual meeting of the Society for Cardiovascular Angiography and Interventions.

The risk score was introduced last year by a team of physicians at William Beaumont Hospital in Royal Oak, Mich. (Am. J. Cardiol. 2004;93:1515-9). Scoring involves eight elements, and a patient can receive 0-11 points (see upper box). The patient scores 2 points if any of the following three features occurs: a baseline creatinine clearance rate of less than 60 mL/min, use of an intraaortic balloon pump during the coronary procedure, and an urgent or emergency coronary procedure. Five other features score 1 point each when present: diabetes, heart failure, hypertension, peripheral vascular disease, and treatment with 260 mL or more of contrast during the procedure.

The scoring system was derived from observations made in more than 10,000 patients and was initially verified with a second group of nearly 10,000 patients. The original report found that patients could be divided into four risk groups: low, with 0-4 points; moderate, with 5-6 points; high, with 7-8 points; and very high, with 9 or more points.

The new validation cohort review by Dr. Skelding and her associates included patients who underwent coronary interventions at St. Mary's Hospital in Rochester, Minn., during 2000-2003. This group included 3,213 patients with baseline data and follow-up that were complete enough to allow analysis.

The rates of contrast-induced nephropathy (CIN) and in-hospital mortality were closely linked with risk score in this new cohort (see lower box). Patients who scored 0-4 points had a 0.2% incidence of nephropathy during follow-up and a 0.5% rate of in-hospital death. Patients with a score of 5-6 had a 2.6% nephropathy rate and a 2.0% mortality rate. Patients with 7-8 points had an 8.2% nephropathy rate and an 8.4% mortality rate. And those with 9-11 points had a 17.3% nephropathy rate and a 25.4% mortality rate, reported Dr. Skelding, a cardiologist at the Mayo Clinic in Rochester, Minn.

This analysis also highlighted the poor prognosis that patients face once they develop CIN. In-hospital mortality occurred in 6.6% of patients who developed CIN, compared with a 1.2% rate in those who did not. Patients with CIN were 5.3-fold more likely to die in the hospital, compared with those without CIN, a statistically significant difference.

In addition to having a prognostic role, the risk score can help guide patient management to avoid CIN, Dr. Skelding said in an interview with this newspaper. Although a few elements of the risk score depend on events that occur during the coronary procedure, such as total contrast volume used and the need for an intraaortic balloon pump, most elements can be assessed prior to the procedure. Patients with relatively high scores before their procedure starts should first receive a 12-hour infusion with normal saline to help prevent CIN. The normal duration of hydration is 3 hours, Dr. Skelding said.

Source: Am. J. Cardiol. 2004;93:1515-9

PONTE VEDRA BEACH, FLA. — An 11-point risk-scoring system can stratify the risk that patients face from contrast-induced nephropathy, on the basis of a validation study that involved more than 3,000 patients.

Applying the risk score in routine practice could identify at-risk patients who should receive a limited amount of contrast during angiography or a percutaneous coronary intervention. It could also identify patients who should receive more intensive prophylaxis, with 12 hours of intravenous hydration with normal saline before having radio-contrast, Kimberly A. Skelding, M.D., said at the annual meeting of the Society for Cardiovascular Angiography and Interventions.

The risk score was introduced last year by a team of physicians at William Beaumont Hospital in Royal Oak, Mich. (Am. J. Cardiol. 2004;93:1515-9). Scoring involves eight elements, and a patient can receive 0-11 points (see upper box). The patient scores 2 points if any of the following three features occurs: a baseline creatinine clearance rate of less than 60 mL/min, use of an intraaortic balloon pump during the coronary procedure, and an urgent or emergency coronary procedure. Five other features score 1 point each when present: diabetes, heart failure, hypertension, peripheral vascular disease, and treatment with 260 mL or more of contrast during the procedure.

The scoring system was derived from observations made in more than 10,000 patients and was initially verified with a second group of nearly 10,000 patients. The original report found that patients could be divided into four risk groups: low, with 0-4 points; moderate, with 5-6 points; high, with 7-8 points; and very high, with 9 or more points.

The new validation cohort review by Dr. Skelding and her associates included patients who underwent coronary interventions at St. Mary's Hospital in Rochester, Minn., during 2000-2003. This group included 3,213 patients with baseline data and follow-up that were complete enough to allow analysis.

The rates of contrast-induced nephropathy (CIN) and in-hospital mortality were closely linked with risk score in this new cohort (see lower box). Patients who scored 0-4 points had a 0.2% incidence of nephropathy during follow-up and a 0.5% rate of in-hospital death. Patients with a score of 5-6 had a 2.6% nephropathy rate and a 2.0% mortality rate. Patients with 7-8 points had an 8.2% nephropathy rate and an 8.4% mortality rate. And those with 9-11 points had a 17.3% nephropathy rate and a 25.4% mortality rate, reported Dr. Skelding, a cardiologist at the Mayo Clinic in Rochester, Minn.

This analysis also highlighted the poor prognosis that patients face once they develop CIN. In-hospital mortality occurred in 6.6% of patients who developed CIN, compared with a 1.2% rate in those who did not. Patients with CIN were 5.3-fold more likely to die in the hospital, compared with those without CIN, a statistically significant difference.

In addition to having a prognostic role, the risk score can help guide patient management to avoid CIN, Dr. Skelding said in an interview with this newspaper. Although a few elements of the risk score depend on events that occur during the coronary procedure, such as total contrast volume used and the need for an intraaortic balloon pump, most elements can be assessed prior to the procedure. Patients with relatively high scores before their procedure starts should first receive a 12-hour infusion with normal saline to help prevent CIN. The normal duration of hydration is 3 hours, Dr. Skelding said.

Source: Am. J. Cardiol. 2004;93:1515-9

PONTE VEDRA BEACH, FLA. — An 11-point risk-scoring system can stratify the risk that patients face from contrast-induced nephropathy, on the basis of a validation study that involved more than 3,000 patients.

Applying the risk score in routine practice could identify at-risk patients who should receive a limited amount of contrast during angiography or a percutaneous coronary intervention. It could also identify patients who should receive more intensive prophylaxis, with 12 hours of intravenous hydration with normal saline before having radio-contrast, Kimberly A. Skelding, M.D., said at the annual meeting of the Society for Cardiovascular Angiography and Interventions.

The risk score was introduced last year by a team of physicians at William Beaumont Hospital in Royal Oak, Mich. (Am. J. Cardiol. 2004;93:1515-9). Scoring involves eight elements, and a patient can receive 0-11 points (see upper box). The patient scores 2 points if any of the following three features occurs: a baseline creatinine clearance rate of less than 60 mL/min, use of an intraaortic balloon pump during the coronary procedure, and an urgent or emergency coronary procedure. Five other features score 1 point each when present: diabetes, heart failure, hypertension, peripheral vascular disease, and treatment with 260 mL or more of contrast during the procedure.

The scoring system was derived from observations made in more than 10,000 patients and was initially verified with a second group of nearly 10,000 patients. The original report found that patients could be divided into four risk groups: low, with 0-4 points; moderate, with 5-6 points; high, with 7-8 points; and very high, with 9 or more points.

The new validation cohort review by Dr. Skelding and her associates included patients who underwent coronary interventions at St. Mary's Hospital in Rochester, Minn., during 2000-2003. This group included 3,213 patients with baseline data and follow-up that were complete enough to allow analysis.

The rates of contrast-induced nephropathy (CIN) and in-hospital mortality were closely linked with risk score in this new cohort (see lower box). Patients who scored 0-4 points had a 0.2% incidence of nephropathy during follow-up and a 0.5% rate of in-hospital death. Patients with a score of 5-6 had a 2.6% nephropathy rate and a 2.0% mortality rate. Patients with 7-8 points had an 8.2% nephropathy rate and an 8.4% mortality rate. And those with 9-11 points had a 17.3% nephropathy rate and a 25.4% mortality rate, reported Dr. Skelding, a cardiologist at the Mayo Clinic in Rochester, Minn.

This analysis also highlighted the poor prognosis that patients face once they develop CIN. In-hospital mortality occurred in 6.6% of patients who developed CIN, compared with a 1.2% rate in those who did not. Patients with CIN were 5.3-fold more likely to die in the hospital, compared with those without CIN, a statistically significant difference.

In addition to having a prognostic role, the risk score can help guide patient management to avoid CIN, Dr. Skelding said in an interview with this newspaper. Although a few elements of the risk score depend on events that occur during the coronary procedure, such as total contrast volume used and the need for an intraaortic balloon pump, most elements can be assessed prior to the procedure. Patients with relatively high scores before their procedure starts should first receive a 12-hour infusion with normal saline to help prevent CIN. The normal duration of hydration is 3 hours, Dr. Skelding said.

Source: Am. J. Cardiol. 2004;93:1515-9