management of atrial fibrillation in older patients
TRANSCRIPT
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 Score
1.9 0
2.8 1
4.0 2
5.9 3
8.5 4
12.5 5
18.2 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 Recommendation
NO risk factors Aspirin
One moderate risk factor Aspirin or warfarin
Any 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/TIA
Age 65-74 HTN Mitral stenosis
Coronary 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 Clopidogrel
Vascular events: 7.6%/year
6.8%/year
Stroke: 3.3% /year 2.4%/year
MI: 0.9% /year 0.7% /year
Bleed: 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