Imaging

ORLANDO, FLA. — Myocardial perfusion imaging substantially restratifies women with a moderate or high Duke Treadmill Score on exercise stress testing, Justin B. Lundbye, M.D., said at the annual meeting of the American College of Cardiology.

“In this subset of women with intermediate to high pretest likelihood of coronary artery disease [CAD] based on Duke Treadmill Score, we feel that consideration should be given to utilization of exercise myocardial perfusion imaging as the first-line test,” asserted Dr. Lundbye of Hartford (Conn.) Hospital.

Current ACC/American Heart Association guidelines recommend exercise stress testing (EST) alone for women with an intermediate or high pretest probability of CAD. But because of the nature of EST, many women will have false-positive results. Perfusion imaging reliably subclassifies women into two groups: those who require further testing and those who do not, he said.

He reported on 1,020 women with an intermediate or high pretest likelihood of significant CAD who underwent EST and technetium-99 sestamibi myocardial perfusion imaging. During a mean 2.4 years of follow-up, women with a moderate Duke Treadmill Score of −10 to +4 (high risk to moderate risk) had a 3% annual rate of all-cause mortality, nonfatal MI, or coronary revascularization performed more than 2 months after their EST. In those who had an abnormal imaging study, the combined annual event rate was 17%. In those with a normal perfusion imaging study, it was 2%.

In women with a high-risk treadmill score of −11 or less, the annual event rate was 12%. Those with an abnormal perfusion scan had an annual event rate of 28%, while those with a negative scan had a rate of 4%.

ORLANDO, FLA. — Myocardial perfusion imaging substantially restratifies women with a moderate or high Duke Treadmill Score on exercise stress testing, Justin B. Lundbye, M.D., said at the annual meeting of the American College of Cardiology.

“In this subset of women with intermediate to high pretest likelihood of coronary artery disease [CAD] based on Duke Treadmill Score, we feel that consideration should be given to utilization of exercise myocardial perfusion imaging as the first-line test,” asserted Dr. Lundbye of Hartford (Conn.) Hospital.

Current ACC/American Heart Association guidelines recommend exercise stress testing (EST) alone for women with an intermediate or high pretest probability of CAD. But because of the nature of EST, many women will have false-positive results. Perfusion imaging reliably subclassifies women into two groups: those who require further testing and those who do not, he said.

He reported on 1,020 women with an intermediate or high pretest likelihood of significant CAD who underwent EST and technetium-99 sestamibi myocardial perfusion imaging. During a mean 2.4 years of follow-up, women with a moderate Duke Treadmill Score of −10 to +4 (high risk to moderate risk) had a 3% annual rate of all-cause mortality, nonfatal MI, or coronary revascularization performed more than 2 months after their EST. In those who had an abnormal imaging study, the combined annual event rate was 17%. In those with a normal perfusion imaging study, it was 2%.

In women with a high-risk treadmill score of −11 or less, the annual event rate was 12%. Those with an abnormal perfusion scan had an annual event rate of 28%, while those with a negative scan had a rate of 4%.

ORLANDO, FLA. — Myocardial perfusion imaging substantially restratifies women with a moderate or high Duke Treadmill Score on exercise stress testing, Justin B. Lundbye, M.D., said at the annual meeting of the American College of Cardiology.

“In this subset of women with intermediate to high pretest likelihood of coronary artery disease [CAD] based on Duke Treadmill Score, we feel that consideration should be given to utilization of exercise myocardial perfusion imaging as the first-line test,” asserted Dr. Lundbye of Hartford (Conn.) Hospital.

Current ACC/American Heart Association guidelines recommend exercise stress testing (EST) alone for women with an intermediate or high pretest probability of CAD. But because of the nature of EST, many women will have false-positive results. Perfusion imaging reliably subclassifies women into two groups: those who require further testing and those who do not, he said.

He reported on 1,020 women with an intermediate or high pretest likelihood of significant CAD who underwent EST and technetium-99 sestamibi myocardial perfusion imaging. During a mean 2.4 years of follow-up, women with a moderate Duke Treadmill Score of −10 to +4 (high risk to moderate risk) had a 3% annual rate of all-cause mortality, nonfatal MI, or coronary revascularization performed more than 2 months after their EST. In those who had an abnormal imaging study, the combined annual event rate was 17%. In those with a normal perfusion imaging study, it was 2%.

In women with a high-risk treadmill score of −11 or less, the annual event rate was 12%. Those with an abnormal perfusion scan had an annual event rate of 28%, while those with a negative scan had a rate of 4%.

WASHINGTON — Even without evidence of coronary calcium on CT, a large proportion of diabetic patients are still at risk for atherosclerosis, Liviu Klein, M.D., said at a conference on cardiovascular disease epidemiology and prevention sponsored by the American Heart Association.

“Diabetics are clearly at risk for atherosclerosis. Some people believe that CAC [coronary artery calcium] is a perfect tool for discrimination, but it's not. … My concern is that the absence of CAC will be used as a reason not to treat,” Dr. Klein, a fellow in cardiovascular epidemiology and prevention at Northwestern University, Chicago, said in an interview.

About 30% of diabetic adults aged 45 and older without clinically manifest coronary heart disease have no CAC (score of 0) on CT. No previous study compared other markers of atherosclerosis in that subgroup with those of nondiabetics without CAC. The first-ever study to do so is a part of the Multi-Ethnic Study of Atherosclerosis (MESA), a population-based cohort of 6,814 African American, white, Chinese, and Hispanic adults aged 45–84 without symptoms or history of cardiovascular disease.

A total of 350 (34%) of the diabetic participants and 2,825 (49%) of the nondiabetic participants had CAC scores of 0 on coronary CT. Diabetic subjects were older than nondiabetics (61 vs. 57 years) and were more likely to be African American (44% vs. 28%) or Hispanic (34% vs. 23%). Average body mass index (BMI), waist circumference, and triglyceride and LDL-cholesterol levels were also higher in the diabetics than in the nondiabetics, Dr. Klein reported.

On B-mode carotid ultrasound, the diabetic patients had significantly higher common and internal carotid intimal medial thickness (IMT) than did nondiabetics, both before and after adjustment for age, gender, ethnicity, and traditional risk factors for atherosclerosis, including blood pressure, cholesterol level, BMI, smoking, socioeconomic status, and use of statins and aspirin.

After adjustment, common carotid IMTs were 0.84 mm for the diabetics and 0.81 mm for the nondiabetics; internal carotid IMTs were 0.98 mm and 0.86 mm, respectively. Levels of intercellular adhesion molecule-1, E-selectin, interleukin-6, and C-reactive protein were all significantly greater in the diabetic group, indicating a greater burden of atherosclerosis, Dr. Klein said.

Mean ankle-brachial index did not differ significantly between the two groups either before or after the same adjustments, nor were there differences in levels of the plaque instability markers matrix metalloproteinase (MMP)-3, MMP-9, or soluble CD40 ligand.

Whether diabetic patients without a history of myocardial infarction have the same risk of CHD events as nondiabetic patients with a history of MI remains controversial, despite two sets of evidence-based guidelines issued by the National Heart, Lung, and Blood Institute categorizing diabetes as a “risk equivalent” for coronary heart disease and advising that all individuals with diabetes receive intensive CHD risk factor management (JAMA 2001;285:2486–97 JAMA 2003;289:2560–72).

However, conflicting data have appeared both before and since the dissemination of those two documents (the Third Report of the National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults and the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure).

One recent study, for example, found that diabetic patients without MI had a lower risk of CHD events and mortality from cardiovascular disease than did nondiabetic patients with MI, but stroke risk was similar between the two groups (Circulation 2004;109:855–60), while another suggested that 5-year survival among diabetics without CAC is similar to that of nondiabetic subjects without CAC (J. Am. Coll. Cardiol. 2004;43:1663–9).

But, according to Dr. Klein, there are multiple problems with these and similar studies.

First, they have not accounted for the fact that mean CAC differs among individuals of different races. In particular, African Americans and Hispanics have lower mean CAC values than do whites, despite having higher MI rates. “We don't really know what the calcium score means,” he said.

Moreover, these new data from MESA show that even if someone with diabetes has a CAC of 0 now, that person is likely to have a significantly higher atherosclerotic burden, compared with a nondiabetic. “If you wait until a diabetic has CAC, you will have missed the chance to prevent diabetes complications. … It's not so much an issue of mortality as it is of morbidity,” Dr. Klein said at the meeting, also sponsored by NHLBI.

As it is, fewer than 25% of diabetics receive appropriate treatment for cholesterol, hypertension, and glucose. That number could drop significantly if physicians use a CAC score of 0 on CT as a threshold for intensive treatment, he noted. “The problem is the more tools you have, the easier it is to just get the test rather than committing yourself to lifestyle modification. … But in diabetics, who clearly have atherosclerosis, you have to treat them.”

WASHINGTON — Even without evidence of coronary calcium on CT, a large proportion of diabetic patients are still at risk for atherosclerosis, Liviu Klein, M.D., said at a conference on cardiovascular disease epidemiology and prevention sponsored by the American Heart Association.

“Diabetics are clearly at risk for atherosclerosis. Some people believe that CAC [coronary artery calcium] is a perfect tool for discrimination, but it's not. … My concern is that the absence of CAC will be used as a reason not to treat,” Dr. Klein, a fellow in cardiovascular epidemiology and prevention at Northwestern University, Chicago, said in an interview.

About 30% of diabetic adults aged 45 and older without clinically manifest coronary heart disease have no CAC (score of 0) on CT. No previous study compared other markers of atherosclerosis in that subgroup with those of nondiabetics without CAC. The first-ever study to do so is a part of the Multi-Ethnic Study of Atherosclerosis (MESA), a population-based cohort of 6,814 African American, white, Chinese, and Hispanic adults aged 45–84 without symptoms or history of cardiovascular disease.

A total of 350 (34%) of the diabetic participants and 2,825 (49%) of the nondiabetic participants had CAC scores of 0 on coronary CT. Diabetic subjects were older than nondiabetics (61 vs. 57 years) and were more likely to be African American (44% vs. 28%) or Hispanic (34% vs. 23%). Average body mass index (BMI), waist circumference, and triglyceride and LDL-cholesterol levels were also higher in the diabetics than in the nondiabetics, Dr. Klein reported.

On B-mode carotid ultrasound, the diabetic patients had significantly higher common and internal carotid intimal medial thickness (IMT) than did nondiabetics, both before and after adjustment for age, gender, ethnicity, and traditional risk factors for atherosclerosis, including blood pressure, cholesterol level, BMI, smoking, socioeconomic status, and use of statins and aspirin.

After adjustment, common carotid IMTs were 0.84 mm for the diabetics and 0.81 mm for the nondiabetics; internal carotid IMTs were 0.98 mm and 0.86 mm, respectively. Levels of intercellular adhesion molecule-1, E-selectin, interleukin-6, and C-reactive protein were all significantly greater in the diabetic group, indicating a greater burden of atherosclerosis, Dr. Klein said.

Mean ankle-brachial index did not differ significantly between the two groups either before or after the same adjustments, nor were there differences in levels of the plaque instability markers matrix metalloproteinase (MMP)-3, MMP-9, or soluble CD40 ligand.

Whether diabetic patients without a history of myocardial infarction have the same risk of CHD events as nondiabetic patients with a history of MI remains controversial, despite two sets of evidence-based guidelines issued by the National Heart, Lung, and Blood Institute categorizing diabetes as a “risk equivalent” for coronary heart disease and advising that all individuals with diabetes receive intensive CHD risk factor management (JAMA 2001;285:2486–97 JAMA 2003;289:2560–72).

However, conflicting data have appeared both before and since the dissemination of those two documents (the Third Report of the National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults and the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure).

One recent study, for example, found that diabetic patients without MI had a lower risk of CHD events and mortality from cardiovascular disease than did nondiabetic patients with MI, but stroke risk was similar between the two groups (Circulation 2004;109:855–60), while another suggested that 5-year survival among diabetics without CAC is similar to that of nondiabetic subjects without CAC (J. Am. Coll. Cardiol. 2004;43:1663–9).

But, according to Dr. Klein, there are multiple problems with these and similar studies.

First, they have not accounted for the fact that mean CAC differs among individuals of different races. In particular, African Americans and Hispanics have lower mean CAC values than do whites, despite having higher MI rates. “We don't really know what the calcium score means,” he said.

Moreover, these new data from MESA show that even if someone with diabetes has a CAC of 0 now, that person is likely to have a significantly higher atherosclerotic burden, compared with a nondiabetic. “If you wait until a diabetic has CAC, you will have missed the chance to prevent diabetes complications. … It's not so much an issue of mortality as it is of morbidity,” Dr. Klein said at the meeting, also sponsored by NHLBI.

As it is, fewer than 25% of diabetics receive appropriate treatment for cholesterol, hypertension, and glucose. That number could drop significantly if physicians use a CAC score of 0 on CT as a threshold for intensive treatment, he noted. “The problem is the more tools you have, the easier it is to just get the test rather than committing yourself to lifestyle modification. … But in diabetics, who clearly have atherosclerosis, you have to treat them.”

WASHINGTON — Even without evidence of coronary calcium on CT, a large proportion of diabetic patients are still at risk for atherosclerosis, Liviu Klein, M.D., said at a conference on cardiovascular disease epidemiology and prevention sponsored by the American Heart Association.

“Diabetics are clearly at risk for atherosclerosis. Some people believe that CAC [coronary artery calcium] is a perfect tool for discrimination, but it's not. … My concern is that the absence of CAC will be used as a reason not to treat,” Dr. Klein, a fellow in cardiovascular epidemiology and prevention at Northwestern University, Chicago, said in an interview.

About 30% of diabetic adults aged 45 and older without clinically manifest coronary heart disease have no CAC (score of 0) on CT. No previous study compared other markers of atherosclerosis in that subgroup with those of nondiabetics without CAC. The first-ever study to do so is a part of the Multi-Ethnic Study of Atherosclerosis (MESA), a population-based cohort of 6,814 African American, white, Chinese, and Hispanic adults aged 45–84 without symptoms or history of cardiovascular disease.

A total of 350 (34%) of the diabetic participants and 2,825 (49%) of the nondiabetic participants had CAC scores of 0 on coronary CT. Diabetic subjects were older than nondiabetics (61 vs. 57 years) and were more likely to be African American (44% vs. 28%) or Hispanic (34% vs. 23%). Average body mass index (BMI), waist circumference, and triglyceride and LDL-cholesterol levels were also higher in the diabetics than in the nondiabetics, Dr. Klein reported.

On B-mode carotid ultrasound, the diabetic patients had significantly higher common and internal carotid intimal medial thickness (IMT) than did nondiabetics, both before and after adjustment for age, gender, ethnicity, and traditional risk factors for atherosclerosis, including blood pressure, cholesterol level, BMI, smoking, socioeconomic status, and use of statins and aspirin.

After adjustment, common carotid IMTs were 0.84 mm for the diabetics and 0.81 mm for the nondiabetics; internal carotid IMTs were 0.98 mm and 0.86 mm, respectively. Levels of intercellular adhesion molecule-1, E-selectin, interleukin-6, and C-reactive protein were all significantly greater in the diabetic group, indicating a greater burden of atherosclerosis, Dr. Klein said.

Mean ankle-brachial index did not differ significantly between the two groups either before or after the same adjustments, nor were there differences in levels of the plaque instability markers matrix metalloproteinase (MMP)-3, MMP-9, or soluble CD40 ligand.

Whether diabetic patients without a history of myocardial infarction have the same risk of CHD events as nondiabetic patients with a history of MI remains controversial, despite two sets of evidence-based guidelines issued by the National Heart, Lung, and Blood Institute categorizing diabetes as a “risk equivalent” for coronary heart disease and advising that all individuals with diabetes receive intensive CHD risk factor management (JAMA 2001;285:2486–97 JAMA 2003;289:2560–72).

However, conflicting data have appeared both before and since the dissemination of those two documents (the Third Report of the National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults and the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure).

One recent study, for example, found that diabetic patients without MI had a lower risk of CHD events and mortality from cardiovascular disease than did nondiabetic patients with MI, but stroke risk was similar between the two groups (Circulation 2004;109:855–60), while another suggested that 5-year survival among diabetics without CAC is similar to that of nondiabetic subjects without CAC (J. Am. Coll. Cardiol. 2004;43:1663–9).

But, according to Dr. Klein, there are multiple problems with these and similar studies.

First, they have not accounted for the fact that mean CAC differs among individuals of different races. In particular, African Americans and Hispanics have lower mean CAC values than do whites, despite having higher MI rates. “We don't really know what the calcium score means,” he said.

Moreover, these new data from MESA show that even if someone with diabetes has a CAC of 0 now, that person is likely to have a significantly higher atherosclerotic burden, compared with a nondiabetic. “If you wait until a diabetic has CAC, you will have missed the chance to prevent diabetes complications. … It's not so much an issue of mortality as it is of morbidity,” Dr. Klein said at the meeting, also sponsored by NHLBI.

As it is, fewer than 25% of diabetics receive appropriate treatment for cholesterol, hypertension, and glucose. That number could drop significantly if physicians use a CAC score of 0 on CT as a threshold for intensive treatment, he noted. “The problem is the more tools you have, the easier it is to just get the test rather than committing yourself to lifestyle modification. … But in diabetics, who clearly have atherosclerosis, you have to treat them.”

ORLANDO, FLA. — Reference norms for coronary artery calcium may be significantly lower than previously believed, Axel Schmermund, M.D., said at the annual meeting of the American College of Cardiology.

This new finding means that a fair number of patients deemed not to have a clinically significant amount of coronary artery calcium (CAC) on electron beam computed tomography (EBCT) for the detection of subclinical atherosclerosis may in truth have more than the average amount for their age—and thus may be at increased risk, explained Dr. Schmermund of the West German Heart Center at the University of Essen.

Until now, the reference standards applied throughout the world in using EBCT for the measurement of CAC as a means of stratifying coronary risk have relied principally on data from four large prospective U.S. studies. The studies involved subjects referred by their physicians or self-referred for EBCT, and hence are subject to several major types of bias.

Dr. Schmermund presented baseline data from the 4,259-subject Heinz Nixdorf RECALL (Risk Factors, Evaluation of Coronary Calcium and Lifestyle) study, the first large prospective study of CAC measurement in an unselected population. “Our subjects were strictly unselected. We approached them, not the other way around,” he noted.

The investigators found the distribution of CAC scores in their German population-based study differed significantly from that in the U.S. studies.

“Compared with American values, the Heinz Nixdorf values for the 50th percentile are all lower, at least in the higher age groups. There is an age shift of approximately 5 years,” Dr. Schmermund said.

This means, for example, that a 67-year-old man with a CAC Agatston score of 150 would be below the age-matched median using the widely cited American reference cohorts—but above the median value using the Heinz Nixdorf data as the reference norm.

Dr. Schmermund said it would be a mistake for American physicians to rely on German CAC EBCT reference data to estimate the cardiovascular risk of U.S. patients, since the two populations differ in various ways. But the Heinz Nixdorf data raise a red flag regarding reliance on reference data that are based on referral populations.

The good news, he added, is that soon American physicians will for the first time have coronary artery calcium reference data obtained prospectively from an unselected, unbiased U.S. population, when the baseline data from the large prospective ongoing National Institutes of Health-sponsored Multiethnic Study of Atherosclerosis (MESA) are published.

ORLANDO, FLA. — Reference norms for coronary artery calcium may be significantly lower than previously believed, Axel Schmermund, M.D., said at the annual meeting of the American College of Cardiology.

This new finding means that a fair number of patients deemed not to have a clinically significant amount of coronary artery calcium (CAC) on electron beam computed tomography (EBCT) for the detection of subclinical atherosclerosis may in truth have more than the average amount for their age—and thus may be at increased risk, explained Dr. Schmermund of the West German Heart Center at the University of Essen.

Until now, the reference standards applied throughout the world in using EBCT for the measurement of CAC as a means of stratifying coronary risk have relied principally on data from four large prospective U.S. studies. The studies involved subjects referred by their physicians or self-referred for EBCT, and hence are subject to several major types of bias.

Dr. Schmermund presented baseline data from the 4,259-subject Heinz Nixdorf RECALL (Risk Factors, Evaluation of Coronary Calcium and Lifestyle) study, the first large prospective study of CAC measurement in an unselected population. “Our subjects were strictly unselected. We approached them, not the other way around,” he noted.

The investigators found the distribution of CAC scores in their German population-based study differed significantly from that in the U.S. studies.

“Compared with American values, the Heinz Nixdorf values for the 50th percentile are all lower, at least in the higher age groups. There is an age shift of approximately 5 years,” Dr. Schmermund said.

This means, for example, that a 67-year-old man with a CAC Agatston score of 150 would be below the age-matched median using the widely cited American reference cohorts—but above the median value using the Heinz Nixdorf data as the reference norm.

Dr. Schmermund said it would be a mistake for American physicians to rely on German CAC EBCT reference data to estimate the cardiovascular risk of U.S. patients, since the two populations differ in various ways. But the Heinz Nixdorf data raise a red flag regarding reliance on reference data that are based on referral populations.

The good news, he added, is that soon American physicians will for the first time have coronary artery calcium reference data obtained prospectively from an unselected, unbiased U.S. population, when the baseline data from the large prospective ongoing National Institutes of Health-sponsored Multiethnic Study of Atherosclerosis (MESA) are published.

ORLANDO, FLA. — Reference norms for coronary artery calcium may be significantly lower than previously believed, Axel Schmermund, M.D., said at the annual meeting of the American College of Cardiology.

This new finding means that a fair number of patients deemed not to have a clinically significant amount of coronary artery calcium (CAC) on electron beam computed tomography (EBCT) for the detection of subclinical atherosclerosis may in truth have more than the average amount for their age—and thus may be at increased risk, explained Dr. Schmermund of the West German Heart Center at the University of Essen.

Until now, the reference standards applied throughout the world in using EBCT for the measurement of CAC as a means of stratifying coronary risk have relied principally on data from four large prospective U.S. studies. The studies involved subjects referred by their physicians or self-referred for EBCT, and hence are subject to several major types of bias.

Dr. Schmermund presented baseline data from the 4,259-subject Heinz Nixdorf RECALL (Risk Factors, Evaluation of Coronary Calcium and Lifestyle) study, the first large prospective study of CAC measurement in an unselected population. “Our subjects were strictly unselected. We approached them, not the other way around,” he noted.

The investigators found the distribution of CAC scores in their German population-based study differed significantly from that in the U.S. studies.

“Compared with American values, the Heinz Nixdorf values for the 50th percentile are all lower, at least in the higher age groups. There is an age shift of approximately 5 years,” Dr. Schmermund said.

This means, for example, that a 67-year-old man with a CAC Agatston score of 150 would be below the age-matched median using the widely cited American reference cohorts—but above the median value using the Heinz Nixdorf data as the reference norm.

Dr. Schmermund said it would be a mistake for American physicians to rely on German CAC EBCT reference data to estimate the cardiovascular risk of U.S. patients, since the two populations differ in various ways. But the Heinz Nixdorf data raise a red flag regarding reliance on reference data that are based on referral populations.

The good news, he added, is that soon American physicians will for the first time have coronary artery calcium reference data obtained prospectively from an unselected, unbiased U.S. population, when the baseline data from the large prospective ongoing National Institutes of Health-sponsored Multiethnic Study of Atherosclerosis (MESA) are published.

LOS ANGELES — Nuclear cardiology scans performed in the emergency department can not only reduce admission rates by ruling out acute coronary syndrome (ACS), but also sound the alert on patients who warrant further testing despite normal laboratory tests, ECGs, and even coronary angioplasty.

“You need to detect those unstable anginas. Otherwise, you'll have a lot of potential events walking out your door,” Jack A. Ziffer, M.D., medical director of nuclear cardiology for Baptist Cardiac and Vascular Institute, Miami, and Baptist Hospital of Miami, said at a meeting sponsored by the American College of Cardiology.

Other ACSs can be missed as well, even by angiography, which misses 3% of MIs and fails to diagnose significant pathology in a third of patients with elevated troponin levels, Dr. Ziffer said at the meeting, cosponsored by the American Society of Nuclear Cardiology and Cedars-Sinai Medical Center.

Spontaneous thrombolysis, prolonged vasospasm, injury location and patient anatomy, and misinterpretation may lead to false-negative test outcomes that might result in a patient being inappropriately discharged. Nuclear cardiology offers a quick, comprehensive look at perfusion and function that can help in clarify diagnoses.

Dr. Ziffer described the emergency department (ED) protocol that has been adopted by Cedars-Sinai and other hospitals.

Any patient who presents with symptoms suggestive of a suspected ACS is injected with radionuclide in the ED in preparation for a nuclear scan. A thorough history is taken, laboratory values are assessed, and an ECG and angiogram are performed. Treatment is commenced based on severity of symptoms and test results. Meanwhile, nuclear imaging is performed after about 30-45 minutes, once some hepatic clearance has been achieved.

Two paradigms direct the myocardial perfusion and function studies ordered for the patient:

▸ In a patient with ongoing chest pain. A rest MIBI (99mTc sestamibi) with gated single-photon emission computed tomography (gSPECT) scan is performed. If this test is normal, along with all other testing, the patient is sent home. If questions are raised, a stress MIBI test is ordered and/or the patient is admitted to the coronary care unit.

▸ In a patient whose pain has resolved. A rest thallium SPECT test is performed, and if questions arise, a stress MIBI gSPECT test follows, with results determining whether a patient will be admitted or can go home.

MRI can be helpful, but it cannot determine the age of an infarct and poses a practical challenge, since few MRI units operate in the middle of the night. Nuclear imaging “is straightforward and can be delivered 24/7,” Dr. Ziffer said.

Even an angiogram, which details anatomy, “doesn't necessarily tell you what you need to know,” he said.

Perfusion, ejection fraction, wall motion, and wall thickening are all clues to underlying abnormalities that can be assessed with nuclear studies. Polar maps, for example, quantify wall thickness throughout the heart, which can be helpful when wall motion is not clear. “These are really very powerful tools. When you see 8% thickening and 19%, that's less than normal. You ought to see 30% thickening in normal myocardium, or 40%,” he said.

Wall motion is another adjunctive clue within scans performed in the acute setting. “If a defect is present, we ask the question, 'Is wall motion normal or abnormal?' Normal wall motion does not mean that it's an artifact,” he said. It may mean the patient has abnormal perfusion, but that the treatment initiated in the ED was effective in treating unstable angina, or that the patient has suffered a small infarct in an area where wall motion cannot be seen.

When wall motion is abnormal, the patient is more likely to have unstable angina and persistent stunning, or an infarct “age unknown: It could be 30 years ago, could be 2 minutes ago, or impending,” he said.

Dr. Ziffer stressed that interpretation of nuclear studies requires an understanding of the impact of the delay between injecting and imaging. Perfusion parameters reflect the situation at the time the patient was injected, while cardiac function parameters are assessed in real time, while the patient is under the camera. “Sometimes the perfusion abnormalities we see may not reflect, in patients with resolved pain, for example, the entire jeopardized area.”

A pattern of discrete perfusion defects was found in a 67-year-old man with atypical epicardial pain. Courtesy Dr. Jack A. Ziffer

LOS ANGELES — Nuclear cardiology scans performed in the emergency department can not only reduce admission rates by ruling out acute coronary syndrome (ACS), but also sound the alert on patients who warrant further testing despite normal laboratory tests, ECGs, and even coronary angioplasty.

“You need to detect those unstable anginas. Otherwise, you'll have a lot of potential events walking out your door,” Jack A. Ziffer, M.D., medical director of nuclear cardiology for Baptist Cardiac and Vascular Institute, Miami, and Baptist Hospital of Miami, said at a meeting sponsored by the American College of Cardiology.

Other ACSs can be missed as well, even by angiography, which misses 3% of MIs and fails to diagnose significant pathology in a third of patients with elevated troponin levels, Dr. Ziffer said at the meeting, cosponsored by the American Society of Nuclear Cardiology and Cedars-Sinai Medical Center.

Spontaneous thrombolysis, prolonged vasospasm, injury location and patient anatomy, and misinterpretation may lead to false-negative test outcomes that might result in a patient being inappropriately discharged. Nuclear cardiology offers a quick, comprehensive look at perfusion and function that can help in clarify diagnoses.

Dr. Ziffer described the emergency department (ED) protocol that has been adopted by Cedars-Sinai and other hospitals.

Any patient who presents with symptoms suggestive of a suspected ACS is injected with radionuclide in the ED in preparation for a nuclear scan. A thorough history is taken, laboratory values are assessed, and an ECG and angiogram are performed. Treatment is commenced based on severity of symptoms and test results. Meanwhile, nuclear imaging is performed after about 30-45 minutes, once some hepatic clearance has been achieved.

Two paradigms direct the myocardial perfusion and function studies ordered for the patient:

▸ In a patient with ongoing chest pain. A rest MIBI (99mTc sestamibi) with gated single-photon emission computed tomography (gSPECT) scan is performed. If this test is normal, along with all other testing, the patient is sent home. If questions are raised, a stress MIBI test is ordered and/or the patient is admitted to the coronary care unit.

▸ In a patient whose pain has resolved. A rest thallium SPECT test is performed, and if questions arise, a stress MIBI gSPECT test follows, with results determining whether a patient will be admitted or can go home.

MRI can be helpful, but it cannot determine the age of an infarct and poses a practical challenge, since few MRI units operate in the middle of the night. Nuclear imaging “is straightforward and can be delivered 24/7,” Dr. Ziffer said.

Even an angiogram, which details anatomy, “doesn't necessarily tell you what you need to know,” he said.

Perfusion, ejection fraction, wall motion, and wall thickening are all clues to underlying abnormalities that can be assessed with nuclear studies. Polar maps, for example, quantify wall thickness throughout the heart, which can be helpful when wall motion is not clear. “These are really very powerful tools. When you see 8% thickening and 19%, that's less than normal. You ought to see 30% thickening in normal myocardium, or 40%,” he said.

Wall motion is another adjunctive clue within scans performed in the acute setting. “If a defect is present, we ask the question, 'Is wall motion normal or abnormal?' Normal wall motion does not mean that it's an artifact,” he said. It may mean the patient has abnormal perfusion, but that the treatment initiated in the ED was effective in treating unstable angina, or that the patient has suffered a small infarct in an area where wall motion cannot be seen.

When wall motion is abnormal, the patient is more likely to have unstable angina and persistent stunning, or an infarct “age unknown: It could be 30 years ago, could be 2 minutes ago, or impending,” he said.

Dr. Ziffer stressed that interpretation of nuclear studies requires an understanding of the impact of the delay between injecting and imaging. Perfusion parameters reflect the situation at the time the patient was injected, while cardiac function parameters are assessed in real time, while the patient is under the camera. “Sometimes the perfusion abnormalities we see may not reflect, in patients with resolved pain, for example, the entire jeopardized area.”

A pattern of discrete perfusion defects was found in a 67-year-old man with atypical epicardial pain. Courtesy Dr. Jack A. Ziffer

LOS ANGELES — Nuclear cardiology scans performed in the emergency department can not only reduce admission rates by ruling out acute coronary syndrome (ACS), but also sound the alert on patients who warrant further testing despite normal laboratory tests, ECGs, and even coronary angioplasty.

“You need to detect those unstable anginas. Otherwise, you'll have a lot of potential events walking out your door,” Jack A. Ziffer, M.D., medical director of nuclear cardiology for Baptist Cardiac and Vascular Institute, Miami, and Baptist Hospital of Miami, said at a meeting sponsored by the American College of Cardiology.

Other ACSs can be missed as well, even by angiography, which misses 3% of MIs and fails to diagnose significant pathology in a third of patients with elevated troponin levels, Dr. Ziffer said at the meeting, cosponsored by the American Society of Nuclear Cardiology and Cedars-Sinai Medical Center.

Spontaneous thrombolysis, prolonged vasospasm, injury location and patient anatomy, and misinterpretation may lead to false-negative test outcomes that might result in a patient being inappropriately discharged. Nuclear cardiology offers a quick, comprehensive look at perfusion and function that can help in clarify diagnoses.

Dr. Ziffer described the emergency department (ED) protocol that has been adopted by Cedars-Sinai and other hospitals.

Any patient who presents with symptoms suggestive of a suspected ACS is injected with radionuclide in the ED in preparation for a nuclear scan. A thorough history is taken, laboratory values are assessed, and an ECG and angiogram are performed. Treatment is commenced based on severity of symptoms and test results. Meanwhile, nuclear imaging is performed after about 30-45 minutes, once some hepatic clearance has been achieved.

Two paradigms direct the myocardial perfusion and function studies ordered for the patient:

▸ In a patient with ongoing chest pain. A rest MIBI (99mTc sestamibi) with gated single-photon emission computed tomography (gSPECT) scan is performed. If this test is normal, along with all other testing, the patient is sent home. If questions are raised, a stress MIBI test is ordered and/or the patient is admitted to the coronary care unit.

▸ In a patient whose pain has resolved. A rest thallium SPECT test is performed, and if questions arise, a stress MIBI gSPECT test follows, with results determining whether a patient will be admitted or can go home.

MRI can be helpful, but it cannot determine the age of an infarct and poses a practical challenge, since few MRI units operate in the middle of the night. Nuclear imaging “is straightforward and can be delivered 24/7,” Dr. Ziffer said.

Even an angiogram, which details anatomy, “doesn't necessarily tell you what you need to know,” he said.

Perfusion, ejection fraction, wall motion, and wall thickening are all clues to underlying abnormalities that can be assessed with nuclear studies. Polar maps, for example, quantify wall thickness throughout the heart, which can be helpful when wall motion is not clear. “These are really very powerful tools. When you see 8% thickening and 19%, that's less than normal. You ought to see 30% thickening in normal myocardium, or 40%,” he said.

Wall motion is another adjunctive clue within scans performed in the acute setting. “If a defect is present, we ask the question, 'Is wall motion normal or abnormal?' Normal wall motion does not mean that it's an artifact,” he said. It may mean the patient has abnormal perfusion, but that the treatment initiated in the ED was effective in treating unstable angina, or that the patient has suffered a small infarct in an area where wall motion cannot be seen.

When wall motion is abnormal, the patient is more likely to have unstable angina and persistent stunning, or an infarct “age unknown: It could be 30 years ago, could be 2 minutes ago, or impending,” he said.

Dr. Ziffer stressed that interpretation of nuclear studies requires an understanding of the impact of the delay between injecting and imaging. Perfusion parameters reflect the situation at the time the patient was injected, while cardiac function parameters are assessed in real time, while the patient is under the camera. “Sometimes the perfusion abnormalities we see may not reflect, in patients with resolved pain, for example, the entire jeopardized area.”

A pattern of discrete perfusion defects was found in a 67-year-old man with atypical epicardial pain. Courtesy Dr. Jack A. Ziffer

NEW ORLEANS — Almost 12% of Americans aged 75 years or older have valvular heart disease, according to echocardiographic findings from an unselected population of 1,745 people.

The prevalence of valvular heart disease was also high (7.8%) in an unselected group of 3,879 Americans aged 65‐74 years, Vuyisile T. Nkomo, M.D., reported in a poster at the annual scientific sessions of the American Heart Association.

This high prevalence of valvular heart disease in the elderly, many of whom were probably asymptomatic, suggests that physicians need to assess elderly patients carefully for valvular disease by their history and physical examination, said Dr. Nkomo, a cardiologist at the Mayo Clinic in Rochester, Minn. An echocardiogram, the definitive way to identify valvular heart disease, should be obtained for people who are suspected to have clinically significant valvular disease.

“Routine screening by echocardiography of all asymptomatic elderly people may be prohibitively expensive,” he told this newspaper. “This may be where handheld echocardiography devices may be useful, if they come to be used as an extension of the physical examination.

“Waiting for symptoms to appear before making a diagnosis of valvular heart disease‐‐or suspecting valvular disease but waiting for symptoms before getting an echocardiogram‐‐may be waiting too long,” Dr. Nkomo added. That's because of the excess risk for people who become symptomatic, compared with those who are still asymptomatic when their valvular disease is first diagnosed.

If an asymptomatic person is found to have, for example, moderately severe mitral regurgitation, then an annual echocardiogram should be done to monitor whether the severity is progressing and intervention is needed, he said.

To examine the prevalence of valvular heart disease in the general population, Dr. Nkomo and his associates sorted through echocardiographic data collected on 11,911 people in three large, population‐based studies that were sponsored by the National Heart, Lung, and Blood Institute. Data came from the Coronary Artery Risk Development in Young Adults (CARDIA) study, the Atherosclerosis Risk in Communities (ARIC) study, and the Cardiovascular Health Study (CHS). The echocardiograms were done between 1989 and 1996 in men and women who were at least 18 years old.

A total of 555 people had valvular heart disease that was of at least moderate severity, representing an overall, age‐ and gender‐adjusted rate of 2.3%. But there was a striking link between age and the prevalence of valve disease: The rate was lowest in people under 45 years old, with a prevalence of 0.7%, and in those aged 45‐54 years old, with a prevalence of 0.4%. The rate rose sharply among the next three age strata. The prevalence of valvular disease among people aged 55‐64 years was 1.9%. The prevalence of all valvular diseases seen was roughly the same between men and women.

NEW ORLEANS — Almost 12% of Americans aged 75 years or older have valvular heart disease, according to echocardiographic findings from an unselected population of 1,745 people.

The prevalence of valvular heart disease was also high (7.8%) in an unselected group of 3,879 Americans aged 65‐74 years, Vuyisile T. Nkomo, M.D., reported in a poster at the annual scientific sessions of the American Heart Association.

This high prevalence of valvular heart disease in the elderly, many of whom were probably asymptomatic, suggests that physicians need to assess elderly patients carefully for valvular disease by their history and physical examination, said Dr. Nkomo, a cardiologist at the Mayo Clinic in Rochester, Minn. An echocardiogram, the definitive way to identify valvular heart disease, should be obtained for people who are suspected to have clinically significant valvular disease.

“Routine screening by echocardiography of all asymptomatic elderly people may be prohibitively expensive,” he told this newspaper. “This may be where handheld echocardiography devices may be useful, if they come to be used as an extension of the physical examination.

“Waiting for symptoms to appear before making a diagnosis of valvular heart disease‐‐or suspecting valvular disease but waiting for symptoms before getting an echocardiogram‐‐may be waiting too long,” Dr. Nkomo added. That's because of the excess risk for people who become symptomatic, compared with those who are still asymptomatic when their valvular disease is first diagnosed.

If an asymptomatic person is found to have, for example, moderately severe mitral regurgitation, then an annual echocardiogram should be done to monitor whether the severity is progressing and intervention is needed, he said.

To examine the prevalence of valvular heart disease in the general population, Dr. Nkomo and his associates sorted through echocardiographic data collected on 11,911 people in three large, population‐based studies that were sponsored by the National Heart, Lung, and Blood Institute. Data came from the Coronary Artery Risk Development in Young Adults (CARDIA) study, the Atherosclerosis Risk in Communities (ARIC) study, and the Cardiovascular Health Study (CHS). The echocardiograms were done between 1989 and 1996 in men and women who were at least 18 years old.

A total of 555 people had valvular heart disease that was of at least moderate severity, representing an overall, age‐ and gender‐adjusted rate of 2.3%. But there was a striking link between age and the prevalence of valve disease: The rate was lowest in people under 45 years old, with a prevalence of 0.7%, and in those aged 45‐54 years old, with a prevalence of 0.4%. The rate rose sharply among the next three age strata. The prevalence of valvular disease among people aged 55‐64 years was 1.9%. The prevalence of all valvular diseases seen was roughly the same between men and women.

NEW ORLEANS — Almost 12% of Americans aged 75 years or older have valvular heart disease, according to echocardiographic findings from an unselected population of 1,745 people.

The prevalence of valvular heart disease was also high (7.8%) in an unselected group of 3,879 Americans aged 65‐74 years, Vuyisile T. Nkomo, M.D., reported in a poster at the annual scientific sessions of the American Heart Association.

This high prevalence of valvular heart disease in the elderly, many of whom were probably asymptomatic, suggests that physicians need to assess elderly patients carefully for valvular disease by their history and physical examination, said Dr. Nkomo, a cardiologist at the Mayo Clinic in Rochester, Minn. An echocardiogram, the definitive way to identify valvular heart disease, should be obtained for people who are suspected to have clinically significant valvular disease.

“Routine screening by echocardiography of all asymptomatic elderly people may be prohibitively expensive,” he told this newspaper. “This may be where handheld echocardiography devices may be useful, if they come to be used as an extension of the physical examination.

“Waiting for symptoms to appear before making a diagnosis of valvular heart disease‐‐or suspecting valvular disease but waiting for symptoms before getting an echocardiogram‐‐may be waiting too long,” Dr. Nkomo added. That's because of the excess risk for people who become symptomatic, compared with those who are still asymptomatic when their valvular disease is first diagnosed.

If an asymptomatic person is found to have, for example, moderately severe mitral regurgitation, then an annual echocardiogram should be done to monitor whether the severity is progressing and intervention is needed, he said.

To examine the prevalence of valvular heart disease in the general population, Dr. Nkomo and his associates sorted through echocardiographic data collected on 11,911 people in three large, population‐based studies that were sponsored by the National Heart, Lung, and Blood Institute. Data came from the Coronary Artery Risk Development in Young Adults (CARDIA) study, the Atherosclerosis Risk in Communities (ARIC) study, and the Cardiovascular Health Study (CHS). The echocardiograms were done between 1989 and 1996 in men and women who were at least 18 years old.

A total of 555 people had valvular heart disease that was of at least moderate severity, representing an overall, age‐ and gender‐adjusted rate of 2.3%. But there was a striking link between age and the prevalence of valve disease: The rate was lowest in people under 45 years old, with a prevalence of 0.7%, and in those aged 45‐54 years old, with a prevalence of 0.4%. The rate rose sharply among the next three age strata. The prevalence of valvular disease among people aged 55‐64 years was 1.9%. The prevalence of all valvular diseases seen was roughly the same between men and women.