Treatment of Treatment of Atrial Atrial Fibrillation in 2009 Fibrillation in 2009 Gregory Marcus, MD Assistant Professor of Medicine Division of Cardiology, Electrophysiology Section University of California, San Francisco No potential conflicts of interest to disclose
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Treatment of Treatment of AtrialAtrialFibrillation in 2009Fibrillation in 2009
Gregory Marcus, MDAssistant Professor of Medicine
Division of Cardiology, Electrophysiology SectionUniversity of California, San Francisco
No potential conflicts of interest to disclose
Epidemiology
• AF is the most common sustained arrhythmia in adults
• It affects at least 2.3 million Americans– Expected to affect > 4 million by 2030
• Affects ~4% of everyone over age 60 and ~10% of everyone over age 80
• The age-adjusted incidence is increasing1
1. Miyasaka Y. Circulation 2006;114:119-125
Epidemiology…so what?• AF is the most common cause of
embolic stroke1
• Rate of stroke in AF patients is 4.5%/ year1
• 15% of all strokes in the US can be attributed to AF2
• AF is associated with an increase in mortality, from 1.3-2 times3
1. Singer. Chest 2004;126:429-4562. Nattel. Lancet 2006;367:262-2723. Page. N Engl J Med 2004;351:2408-16
Case
• A 58 yo man presents with fatigue and dyspnea on exertion
R heumatic heart diseaseA trial myxomaT hyrotoxicosis
1. Complete history and physical examination
2. Transthoracic Echocardiogram
What work-up does he need?
A trial myxomaT hyrotoxicosis
1. Complete history and physical examination
2. Transthoracic Echocardiogram
What work-up does he need?1. Complete history and physical examination
2. Transthoracic Echocardiogram
-- Left ventricular hypertrophy
-- Hypertrophic obstructive cardiomyopathy
-- occult valvular disease
-- occult pericardial disease
What work-up does he need?
T hyrotoxicosis
1. Complete history and physical examination
2. Transthoracic Echocardiogram
3. Routine labs and thyroid function tests
What work-up does he need?
1. ACC/ AHA Guidelines for Management of Patients with AtrialFibrillation. J Am Coll Cardiol 2006;48:e149-246
2. N Engl J Med 2004;351:2408-16 (they add CXR)
1. Complete history and physical examination
2. Transthoracic Echocardiogram
3. Routine labs and thyroid function tests
*
*
The Best Next Step is…
1 = Rate control and allow atrial fibrillation to continue
2 = Make efforts to achieve and maintain sinus rhythm
3 = 1 and 2 are equal
Rate or Rhythm Control?
• Sinus is better than atrial fibrillation, right?
• Means to maintain sinus rhythm are suboptimal
• Randomized trials
Rate or Rhythm Control?
Inclusion:• ≥ 65 years old with a risk factor for stroke or death
– Of 4070 enrolled, 71% HTN, 26% CAD, 23%CHFIntervention:• Randomized to rate control with anticoagulation versus rhythm
control with cadioversion and antiarrhythmic drugs– Warfarin therapy could be stopped at the discretion of the prescribing
physician after sinus rhythm had been maintained in the rhythm control group for 4 and preferably 12 weeks
Outcomes:• Primary: No overall difference in mortality, trend towards
increased mortality in the rhythm control group • No overall difference in quality of life• No overall difference in stroke
Rate or Rhythm Control?
STAF (n=200)- no difference in composite endpoint of death and thromboembolic events
PIAF (n=252)- No difference in symptomatic improvement
HOT CAFÉ (n=205)- No difference in composite death, thromboembolic events, hemorrhage
Rate or Rhythm Control?
Inclusion:• ≥ 65 years old with a risk factor for stroke or death
– Of 4070 enrolled, 71% HTN, 26% CAD, 23%CHFIntervention:• Randomized to rate control with anticoagulation versus rhythm
control with cadioversion and antiarrhythmic drugs– Warfarin therapy could be stopped at the discretion of the prescribing
physician after sinus rhythm had been maintained in the rhythm control group for 4 and preferably 12 weeks
Outcomes:• Primary: No overall difference in mortality, trend towards
increased mortality in the rhythm control group • No overall difference in quality of life• No overall difference in stroke
-- Antiarrhythmic agents can be proarrhythmic-- Efficacy is poor: 23-63% in NSR in rhythm control group in these trials-- Reanalysis of on-treatment outcomes in AFFIRM showed that the presence of sinus rhythm was associated with a 47% reduction in mortality (p<0.0001)1
1. Circulation 2004;109:1509-13
Outcomes:• Primary: No overall difference in mortality, trend towards
increased mortality in the rhythm control group • No overall difference in quality of life• No overall difference in stroke
Outcomes:• Primary: No overall difference in mortality, trend towards
increased mortality in the rhythm control group • No overall difference in quality of life• No overall difference in stroke
-- Symptomatic patients unlikely to be enrolled-- Symptoms despite rate control are an appropriate reason to consider cardioversion
Outcomes:• Primary: No overall difference in mortality, trend towards
increased mortality in the rhythm control group • No overall difference in quality of life• No overall difference in stroke
-- Strokes occurred in patients off warfarin or with subtherapeutic INR (< 2.0)
-- AF is often asymptomatic! Even in patients with symptomatic AF!1
1. Circulation 1994;89:224-7.
A clear lesson from these trials:
**A rhythm control strategy does not negate the need for warfarin therapy**
… assuming warfarin is indicated
Anticoagulation in AFWho needs it?
• Warfarin is the most effective available therapy to prevent stroke in patients with AF– 5 RCT of vit K antagonists v. placebo highly
significant risk reduction in stroke of 62% (95% CI 48% to 72%)1
– Strokes on warfarin are significantly less severe2
– Warfarin reduced overall mortality in AF patients2
1. Ann Intern Med 1999;131:492-501
2. Chest 2004;126:429S-456S)
3. Eur Heart J 2005;7:C12-18
Anticoagulation in AFWho needs it?
• Warfarin is not perfect– Significantly increase major bleeding (0.9%
to 2.2%) and intracerebral hemorrhage (0.2% to 0.4%)1
– Most efficacy with INR> 2, least bleeding with INR <32
1. Eur Heart J 2005;7:C12-18
2. Chest 2004;126:429S-456S
Anticoagulation in AFWho needs it?
• Aspirin has some efficacy versus placebo, but inferior to warfarin1
– Less bleeding risk
1. Chest 2004;126:429S-456S
The Best Next Step is..
1 = No anticoagulation
2 = Aspirin
3 = Warfarin
4 = Aspirin or Warfarin
Anticoagulation in AFWho needs it?
CHADS 2 score:11 point for:
CHF (or reduced systolic function), HTN, age ≥ 75 years, DM
2 points for:History of stroke or TIA
0-1: low risk2-3: moderate risk4-6: high risk
1. JAMA 2001;285:2864-2870
Anticoagulation- who needs it?
• Class I: If more than one risk factor warfarin
• Class IIa: If just one risk factor, depending on assessment of bleeding risk, ability to safely administrate, and patient preference aspirin (81-325 mg) or warfarin
• Class IIa: If one or more “less well established” risk factors: age 66-74, female gender, or CAD aspirin or warfarin
Anticoagulation- extra tid-bit
• Class IIa: If no mechanical valve, can interrupt anticoagulation for up to 1 week without substituting heparin for procedures, etc.
Anticoagulation in AFWho needs it?
Wait, wait, wait…so what about my 90 year old frail patient?
• Although the risk of warfarin related bleeding increases primarily with anticoagulation intensity and age, the greater risk of stroke in the elderly outweighs the risk of bleeding.1
• One analysis of bleeding risk in the elderly suggested no important role of factors such as a history of falls, presumed age-related incompetence in the control of anticoagulation, or a history of stroke2
-- Non-compliance with INR monitoring, bleeding diasthesis, and poorly controlled HTN (>160/90) were risk factors
1. Lancet 2006;367:262-72
2. Arch Intern Med 2003;163:1580-86
Anticoagulation- extra tid-bits
• Class III: Long-term vitamin K antagonists are not recommended for primary prevention of stroke in patients younger than 60 without heart disease
Unless…
I decide to go with
• Most thrombi in atrial fibrillation arise from the left atrialappendage
• Cardioversion can reduce left atrial appendage function
-- Even from AF to sinus
• The pericardioversion period is a particularly pro-thrombotic time
-- Regardless of mode: DC/ electrical, pharmacologic, spontaneous
I decide to go with
• Prior to cardioversion:1, 2
-- Can exclude preexisitngthrombus by TEE
-- Can anticoagulate (therapeutic/ INR 2-3) for at least 3 weeks prior to cardioversion
1. JACC 2006;48:e149-246
2. Chest 2004;126:429S-456
I decide to go with
• During and after cardioversion:1, 2
-- Anticoagulation for at least 4 weeks
-- Applies even to those who would otherwise not require anticoagulation
• The magic 48 hours
-- Must be documented!1. JACC 2006;48:e149-246
2. Chest 2004;126:429S-456
I decide to go with Rate Control
• Beta-blockers and nondihydropyridine calcium channel blockers are first line1
-- Metoprolol, atenolol, propanolol, even carvedilol2
-- diltiazem or verapamil
• Digoxin is second line because heart rates often increase with exercise
-- Combination with another AV nodal blocking agent can be very effective3
1. JACC 2006;48:e149-246
2. Eur J Heart Fail 2001;3:437-40
3. JACC 1999;33:304-10
Ablation
• High success (> 90-95%) and low risk (< 1%): – AV nodal ablation and pacemaker– Atrial flutter ablation– SVT ablation
Ablation
• Lower success (60-90%) and higher risk (4-6%):1-5