Management of Atrial Fibrillation in older

patientsDebra Bynum, MD

Associate Professor of MedicineDivision of Geriatric Medicine

Recurrent: 2 or more episodes

Paroxysmal: recurrent atrial fibrillaiton that terminates spontaneously

Persistent: a fib more than 7 days

Long Standing afib: greater than one year

Permanent afib: longstanding afib in which cardioversion has failed or not attempted

Classification of Atrial Fibrillation

Causes◦ Acute MI◦ Cardiac surgery◦ Pericarditis◦ Myocarditis◦ Hyperthyroidism◦ PE◦ Pneumonia

Concurrence◦ AF and secondary causes are both common

and may be true, true and unrelated….

Secondary AF

Younger (under 60) No clinical cardiac disease No HTN Normal echo Otherwise normal EKG Good prognosis 12-30% of total cases of AF are Lone

AF

Lone AF

Absence of rheumatic mitral valve disease, prosthetic heart valve or mitral valve repair

Often carries less risk of thromboembolism

Nonvalvular AF

General population: 0.4% -1 %

8 % in those older than 80

Median age: 75

70% of all patients with AF are between 65-85

Increased in patients with underlying CHF

Prevalence as a Geriatric Disease

Overall: 2-7% /year

1 of every 6 strokes occur in patients with AF

Impact of age:◦ Annual risk of stroke from Framingham data

50-59 year olds: 1.5 %/year 80-89 year olds: over 10% /year

Stroke Risk

CHADS2

◦CHF◦HTN◦Age over 75◦Diabetes◦Stroke or TIA(2 points)

Assessing Stroke Risk

Adjusted Stroke Rate (%/yr) CHADS 2 Score1.9 02.8 14.0 25.9 38.5 412.5 518.2 6

CHADS2 and Adjusted Stroke

0= aspirin

1 or 2= either warfarin or ASA (see next slide)

3 or more: warfarin

CHADS2 and anticoagulation recommendations

Risk Category RecommendationNO risk factors AspirinOne moderate risk factor Aspirin or warfarinAny high-risk factor or more than 1 moderate risk factor

warfarin

AHA guidelines for antithrombotic therapy with AF

Less validated risk factors

Moderate Risk Factors

High Risk Factors

Female gender Age over 75 Prior CVA/TIAAge 65-74 HTN Mitral stenosisCoronary artery disease

CHF Prosthetic heart valve

thyrotoxicosis EF <35% or DM

Circulation 2006

5 large RCTs in early 1990s for prevention of thromboembolism in patients with nonvalvular AF

◦ Overall 60% reduction in risk of stroke after 1-2 year follow up

◦ INR 2-3 ideal

◦ Average age of patients: 69

◦ Caveat: Patient age and intensity of anticoagulation are most important predictors of bleeding

Warfarin

Better than nothing but not as good as warfarin

Aspirin

ACTIVE trial, NEJM May 2009 Clopidogrel and ASA with AF better than

ASA alone, but higher risk of bleeding

Aspirin and Clopidogrel

ASA ASA and ClopidogrelVascular events: 7.6%/year

6.8%/year

Stroke: 3.3% /year 2.4%/yearMI: 0.9% /year 0.7% /yearBleed: 1.3%/year 2.0%/year

OAC vs control: 2-3% /year vs 6-8%/yearASA vs control: 5 %/year vs 6%/yearOAC vs ASA: 2-3%/year vs 5%/year

OAC vs nothing: 68% RRRASA vs nothing: 21% RRROAC vs ASA: 52% RRR

Efficacy of anticoagulation (OAC) at preventing stroke (pooled data from RCTs)

Major bleeding in pooled data from RCTs = 1.2 %/year

Increased bleeding with increased age and higher INR

ICH: 0.5%/year on OAC (one study with older patients and INR closer to 4 had ICH rates of 1.8%/year)

Goal INR in older patients: 2-3

Risk of Bleeding

Care with applying data to frail elders who would have been excluded from trials

But more often we still overly estimate risk and underestimate benefit

◦ Survey of Cardiologist registry of patients with AF: 70-80% patients at high risk of CVA (CHADS2 over

2) received warfarin >40% with CHADS 2 of 0 received warfarin!

Weighing Risks and Benefits

“It is well known that atrial fibrillation is associated with a number of clinical problems, including death, thromboembolism (primarily stroke), heart failure, and other morbidity and symptoms. However, association does not prove cause and effect… An apparently widely held view is that if atrial fibrillation can be abolished, the problems associated with atrial fibrillation would be abolished... Such thinking ignores the probability that these clinical problems are at least partly caused by the disease process causing atrial fibrillation….

Dr. George Wyse

Rate vs Rhythm Control

5 RCTs, over 5000 patients studied

NO difference in outcomes

Death, stroke, QOL all same

Slight increase in ADEs and hospitalizations in Rhythm control group

AFFIRM: maybe slightly better outcomes with rhythm control in patients with severe LV dysfunction

Rate vs Rhythm Summary

600 + patients, RCT

Lenient control: Target resting HR <110

Strict control: resting target HR <80 and exercise target HR <110

Strict vs Lenient Rate Control (April 2010 NEJM)

Resting HR Lenient Rate Control

Strict Rate Control

<70 0.3% 22%70-80 1.6% 53.1%81-90 36% 12.9%91-100 39.5% 6.6%>100 22.5% 5.3%Resting Target HR achieved

97.7% 75.2%

Target exercise HR achieved

72.6%

Patients reaching Target

No difference in combined events

No difference in hospitalizations or CHF

Death: 5.6% in lenient group vs 6.6% strict group (nonsignificant)

BUT fewer in strict control group achieved target HR

Overall Results

AF common and associated with mortality, hospitalizations, CHF, stroke

Many studies exclude older patients

Consider individual risk for each patient– we tend to overestimate risk and underestimate benefit

Use CHADS2 and guidelines to help determine use of anticoagulation

Rate control is as good as rhythm control

Moderate rate control is likely as good as attempts at more strict rate control

Summary