Management of atrial fibrillation

Atrial fibrillation is a common disorder with a lifetime prevalence of approximately 10%-15%. Risk factors include advancing age, diabetes, myocardial infarction, valvular disease, smoking, hypertension, obstructive sleep apnea, hyperthyroidism, alcohol abuse, illicit drug use, and obesity.

The diagnosis of AF should be based on the patient’s history and physical exam, including an ECG and lab work to evaluate thyroid, renal, and hepatic function, as well as a blood count. Further testing should be individualized and may include exercise testing, Holter monitoring, transesophageal echocardiogram (TEE), electrophysiology study, sleep study, or chest x-ray.

An important consideration in the approach to AF is prevention of thromboembolic events; multiple scoring systems have been developed to help stratify risk. The guideline recommends using the newer CHA2DS2-VASc scoring system, rather than the older CHADS2 scoring system, for patients with nonvalvular AF. Points are awarded as follows: congestive heart failure, 1; hypertension, 1; age of 75 years or older, 2; diabetes mellitus, 1; stroke/transient ischemic attack, 2; vascular disease (myocardial infarction, peripheral arterial disease, or aortic plaque), 1; age 65-74 years, 1; sex category (female), 1; for a maximum of 9 points. The CHA2DS2-VASc system reflects the increased risk attributed to age of 75 years or older, vascular disease, and female sex not accounted for in the CHADS2 system, and it is better than CHADS2 at discriminating among low-risk individuals. The annual risk of stroke ranges from less than 1% for a score of 0, to greater than 15% with a score of 9.

In patients with nonvalvular AF with a CHA2DS2-VASc score of 0, it is reasonable to forego antithrombotic therapy altogether. For patients with nonvalvular AF and a CHA2DS2-VASc score of 1, it is reasonable to choose either no anticoagulation therapy or use of daily aspirin or an oral anticoagulant. For a CHA2DS2-VASc score of 2, using an oral anticoagulant is recommended, either warfarin or a newer agent – dabigatran, rivaroxaban, or apixaban. For patients who have mechanical heart valves, warfarin is the only recommended choice for anticoagulation, with dabigatran specifically noted as causing harm.

Prevention of thromboembolism is just one of the treatment goals in AF. Affected patients generally require either rate- or rhythm-control therapy. Choosing which treatment to pursue depends on multiple individualized factors. The guideline points out that over time, attempting to maintain sinus rhythm results in more hospitalizations than does therapy focused on rate control, with no decrease in mortality. The guidelines state: "Routine use of a rhythm-control strategy is not warranted for some patients." Persistent symptoms are the most important indication for a rhythm-control strategy.

If a rate-control approach is chosen, the guideline recommends choosing a beta-blocker or nondihydropyridine calcium channel blocker as first-line therapy unless contraindicated, regardless of whether the AF is paroxysmal, persistent, or permanent. The dose of these medications should be titrated according to resting heart rate. Previously a target of fewer than 80 bpm was recommended; however, findings from the RACE-II (Rate Control Efficacy in Permanent Atrial Fibrillation) trial demonstrated no higher rates of cardiovascular death, hospitalization for heart failure, stroke, embolism, bleeding, or life-threatening arrhythmic events in patients with permanent AF who were allowed a target heart rate of fewer than 110 bpm.

While it is not clear if the conclusions of the RACE-II trial are applicable to all patients, the guideline recommends that for patients with permanent AF, it is reasonable to use a goal heart rate of fewer than 110 bpm if the patient is still asymptomatic and maintains normal left ventricular function. If rate control cannot be achieved using beta-blockers or calcium channel blockers, amiodarone may be a reasonable choice.

It may be reasonable to pursue restoration of sinus rhythm in patients with persistent, bothersome symptoms, a first episode of AF, or an acute illness or event leading to the onset of AF. Other situations where a rhythm-control approach may be reasonable include young patient age, inadequate rate control despite appropriate therapy, tachycardia-mediated cardiomyopathy, or patient preference.

If considering cardioversion, the length of time the patient has been in AF is critical. If the onset of AF can be reliably pinpointed to fewer than 48 hours ago, the guideline states that cardioversion is reasonable at that point, and preprocedure anticoagulation is not necessary if the patient is at low risk for thromboembolic events. If the duration of AF is 48 hours or unknown, anticoagulation with warfarin or a newer agent for 3 weeks prior to and 4 weeks after cardioversion is recommended. Alternatively, the preprocedure period of anticoagulation can be eliminated if anticoagulation can be established and a TEE performed that shows no thrombus in the left atrium (LA) or left atrium appendage (LAA).

For patients who achieve sinus rhythm, there are several choices of antiarrhythmic agent to be considered for a rhythm-control strategy, including amiodarone, dofetilide, dronedarone, flecainide, propafenone, and sotalol. It is important to note that these medications are reasonable to continue even if the patient experiences episodes of AF, if the medication decreases the number of episodes or the symptoms associated with them. These medications should be stopped, however, if AF becomes permanent.

The bottom line

Atrial fibrillation is a common rhythm disorder that requires ongoing management of thromboembolic risk as well as adherence to either a rate-control or rhythm-control strategy. The choice for anticoagulation should be made jointly between the patient and physician, and should be based on the CHA2DS2-VASc score.

Reference

2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the Heart Rhythm Society (Circulation 2014 March 28 [doi: 10.1161/CIR.0000000000000040]).

Dr. Skolnik is associate director of the family medicine residency program at Abington (Pa.) Memorial Hospital and professor of family and community medicine at Temple University, Philadelphia. Dr. George-Reichley is a third-year resident in the family medicine residency program at Abington Memorial Hospital.

Atrial fibrillation is a common disorder with a lifetime prevalence of approximately 10%-15%. Risk factors include advancing age, diabetes, myocardial infarction, valvular disease, smoking, hypertension, obstructive sleep apnea, hyperthyroidism, alcohol abuse, illicit drug use, and obesity.

The diagnosis of AF should be based on the patient’s history and physical exam, including an ECG and lab work to evaluate thyroid, renal, and hepatic function, as well as a blood count. Further testing should be individualized and may include exercise testing, Holter monitoring, transesophageal echocardiogram (TEE), electrophysiology study, sleep study, or chest x-ray.

An important consideration in the approach to AF is prevention of thromboembolic events; multiple scoring systems have been developed to help stratify risk. The guideline recommends using the newer CHA2DS2-VASc scoring system, rather than the older CHADS2 scoring system, for patients with nonvalvular AF. Points are awarded as follows: congestive heart failure, 1; hypertension, 1; age of 75 years or older, 2; diabetes mellitus, 1; stroke/transient ischemic attack, 2; vascular disease (myocardial infarction, peripheral arterial disease, or aortic plaque), 1; age 65-74 years, 1; sex category (female), 1; for a maximum of 9 points. The CHA2DS2-VASc system reflects the increased risk attributed to age of 75 years or older, vascular disease, and female sex not accounted for in the CHADS2 system, and it is better than CHADS2 at discriminating among low-risk individuals. The annual risk of stroke ranges from less than 1% for a score of 0, to greater than 15% with a score of 9.

In patients with nonvalvular AF with a CHA2DS2-VASc score of 0, it is reasonable to forego antithrombotic therapy altogether. For patients with nonvalvular AF and a CHA2DS2-VASc score of 1, it is reasonable to choose either no anticoagulation therapy or use of daily aspirin or an oral anticoagulant. For a CHA2DS2-VASc score of 2, using an oral anticoagulant is recommended, either warfarin or a newer agent – dabigatran, rivaroxaban, or apixaban. For patients who have mechanical heart valves, warfarin is the only recommended choice for anticoagulation, with dabigatran specifically noted as causing harm.

Prevention of thromboembolism is just one of the treatment goals in AF. Affected patients generally require either rate- or rhythm-control therapy. Choosing which treatment to pursue depends on multiple individualized factors. The guideline points out that over time, attempting to maintain sinus rhythm results in more hospitalizations than does therapy focused on rate control, with no decrease in mortality. The guidelines state: "Routine use of a rhythm-control strategy is not warranted for some patients." Persistent symptoms are the most important indication for a rhythm-control strategy.

If a rate-control approach is chosen, the guideline recommends choosing a beta-blocker or nondihydropyridine calcium channel blocker as first-line therapy unless contraindicated, regardless of whether the AF is paroxysmal, persistent, or permanent. The dose of these medications should be titrated according to resting heart rate. Previously a target of fewer than 80 bpm was recommended; however, findings from the RACE-II (Rate Control Efficacy in Permanent Atrial Fibrillation) trial demonstrated no higher rates of cardiovascular death, hospitalization for heart failure, stroke, embolism, bleeding, or life-threatening arrhythmic events in patients with permanent AF who were allowed a target heart rate of fewer than 110 bpm.

While it is not clear if the conclusions of the RACE-II trial are applicable to all patients, the guideline recommends that for patients with permanent AF, it is reasonable to use a goal heart rate of fewer than 110 bpm if the patient is still asymptomatic and maintains normal left ventricular function. If rate control cannot be achieved using beta-blockers or calcium channel blockers, amiodarone may be a reasonable choice.

It may be reasonable to pursue restoration of sinus rhythm in patients with persistent, bothersome symptoms, a first episode of AF, or an acute illness or event leading to the onset of AF. Other situations where a rhythm-control approach may be reasonable include young patient age, inadequate rate control despite appropriate therapy, tachycardia-mediated cardiomyopathy, or patient preference.

If considering cardioversion, the length of time the patient has been in AF is critical. If the onset of AF can be reliably pinpointed to fewer than 48 hours ago, the guideline states that cardioversion is reasonable at that point, and preprocedure anticoagulation is not necessary if the patient is at low risk for thromboembolic events. If the duration of AF is 48 hours or unknown, anticoagulation with warfarin or a newer agent for 3 weeks prior to and 4 weeks after cardioversion is recommended. Alternatively, the preprocedure period of anticoagulation can be eliminated if anticoagulation can be established and a TEE performed that shows no thrombus in the left atrium (LA) or left atrium appendage (LAA).

For patients who achieve sinus rhythm, there are several choices of antiarrhythmic agent to be considered for a rhythm-control strategy, including amiodarone, dofetilide, dronedarone, flecainide, propafenone, and sotalol. It is important to note that these medications are reasonable to continue even if the patient experiences episodes of AF, if the medication decreases the number of episodes or the symptoms associated with them. These medications should be stopped, however, if AF becomes permanent.

The bottom line

Atrial fibrillation is a common rhythm disorder that requires ongoing management of thromboembolic risk as well as adherence to either a rate-control or rhythm-control strategy. The choice for anticoagulation should be made jointly between the patient and physician, and should be based on the CHA2DS2-VASc score.

Reference

2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the Heart Rhythm Society (Circulation 2014 March 28 [doi: 10.1161/CIR.0000000000000040]).

Dr. Skolnik is associate director of the family medicine residency program at Abington (Pa.) Memorial Hospital and professor of family and community medicine at Temple University, Philadelphia. Dr. George-Reichley is a third-year resident in the family medicine residency program at Abington Memorial Hospital.

Atrial fibrillation is a common disorder with a lifetime prevalence of approximately 10%-15%. Risk factors include advancing age, diabetes, myocardial infarction, valvular disease, smoking, hypertension, obstructive sleep apnea, hyperthyroidism, alcohol abuse, illicit drug use, and obesity.

The diagnosis of AF should be based on the patient’s history and physical exam, including an ECG and lab work to evaluate thyroid, renal, and hepatic function, as well as a blood count. Further testing should be individualized and may include exercise testing, Holter monitoring, transesophageal echocardiogram (TEE), electrophysiology study, sleep study, or chest x-ray.

An important consideration in the approach to AF is prevention of thromboembolic events; multiple scoring systems have been developed to help stratify risk. The guideline recommends using the newer CHA2DS2-VASc scoring system, rather than the older CHADS2 scoring system, for patients with nonvalvular AF. Points are awarded as follows: congestive heart failure, 1; hypertension, 1; age of 75 years or older, 2; diabetes mellitus, 1; stroke/transient ischemic attack, 2; vascular disease (myocardial infarction, peripheral arterial disease, or aortic plaque), 1; age 65-74 years, 1; sex category (female), 1; for a maximum of 9 points. The CHA2DS2-VASc system reflects the increased risk attributed to age of 75 years or older, vascular disease, and female sex not accounted for in the CHADS2 system, and it is better than CHADS2 at discriminating among low-risk individuals. The annual risk of stroke ranges from less than 1% for a score of 0, to greater than 15% with a score of 9.

In patients with nonvalvular AF with a CHA2DS2-VASc score of 0, it is reasonable to forego antithrombotic therapy altogether. For patients with nonvalvular AF and a CHA2DS2-VASc score of 1, it is reasonable to choose either no anticoagulation therapy or use of daily aspirin or an oral anticoagulant. For a CHA2DS2-VASc score of 2, using an oral anticoagulant is recommended, either warfarin or a newer agent – dabigatran, rivaroxaban, or apixaban. For patients who have mechanical heart valves, warfarin is the only recommended choice for anticoagulation, with dabigatran specifically noted as causing harm.

Prevention of thromboembolism is just one of the treatment goals in AF. Affected patients generally require either rate- or rhythm-control therapy. Choosing which treatment to pursue depends on multiple individualized factors. The guideline points out that over time, attempting to maintain sinus rhythm results in more hospitalizations than does therapy focused on rate control, with no decrease in mortality. The guidelines state: "Routine use of a rhythm-control strategy is not warranted for some patients." Persistent symptoms are the most important indication for a rhythm-control strategy.

If a rate-control approach is chosen, the guideline recommends choosing a beta-blocker or nondihydropyridine calcium channel blocker as first-line therapy unless contraindicated, regardless of whether the AF is paroxysmal, persistent, or permanent. The dose of these medications should be titrated according to resting heart rate. Previously a target of fewer than 80 bpm was recommended; however, findings from the RACE-II (Rate Control Efficacy in Permanent Atrial Fibrillation) trial demonstrated no higher rates of cardiovascular death, hospitalization for heart failure, stroke, embolism, bleeding, or life-threatening arrhythmic events in patients with permanent AF who were allowed a target heart rate of fewer than 110 bpm.

While it is not clear if the conclusions of the RACE-II trial are applicable to all patients, the guideline recommends that for patients with permanent AF, it is reasonable to use a goal heart rate of fewer than 110 bpm if the patient is still asymptomatic and maintains normal left ventricular function. If rate control cannot be achieved using beta-blockers or calcium channel blockers, amiodarone may be a reasonable choice.

It may be reasonable to pursue restoration of sinus rhythm in patients with persistent, bothersome symptoms, a first episode of AF, or an acute illness or event leading to the onset of AF. Other situations where a rhythm-control approach may be reasonable include young patient age, inadequate rate control despite appropriate therapy, tachycardia-mediated cardiomyopathy, or patient preference.

If considering cardioversion, the length of time the patient has been in AF is critical. If the onset of AF can be reliably pinpointed to fewer than 48 hours ago, the guideline states that cardioversion is reasonable at that point, and preprocedure anticoagulation is not necessary if the patient is at low risk for thromboembolic events. If the duration of AF is 48 hours or unknown, anticoagulation with warfarin or a newer agent for 3 weeks prior to and 4 weeks after cardioversion is recommended. Alternatively, the preprocedure period of anticoagulation can be eliminated if anticoagulation can be established and a TEE performed that shows no thrombus in the left atrium (LA) or left atrium appendage (LAA).

For patients who achieve sinus rhythm, there are several choices of antiarrhythmic agent to be considered for a rhythm-control strategy, including amiodarone, dofetilide, dronedarone, flecainide, propafenone, and sotalol. It is important to note that these medications are reasonable to continue even if the patient experiences episodes of AF, if the medication decreases the number of episodes or the symptoms associated with them. These medications should be stopped, however, if AF becomes permanent.

The bottom line

Atrial fibrillation is a common rhythm disorder that requires ongoing management of thromboembolic risk as well as adherence to either a rate-control or rhythm-control strategy. The choice for anticoagulation should be made jointly between the patient and physician, and should be based on the CHA2DS2-VASc score.

Reference

2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the Heart Rhythm Society (Circulation 2014 March 28 [doi: 10.1161/CIR.0000000000000040]).

Dr. Skolnik is associate director of the family medicine residency program at Abington (Pa.) Memorial Hospital and professor of family and community medicine at Temple University, Philadelphia. Dr. George-Reichley is a third-year resident in the family medicine residency program at Abington Memorial Hospital.