2/13/2015
Atrial Fibrillation It Doesn’t Have to Be Irregular Anymore Edward Goldstein PA-C Lead Electrophysiology PA. UCVA Cardiology Rochester,NY
Disclosure • None
LEARNING POINTS What is Atrial Fibrillation? Why do we care? Treatment Options:Rate vs Rhythm Anticoagulation: Coumadin vs NOACs
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Cardiac conduction • How does conduction appear on an ECG? • Cardiac conduction results in the mechanical beating of the heart. – Mechanical beating is created by electrical impulses moving throughout the conduction system • Specific waves that appear on an ECG correspond both to the mechanical and the electrical depolarization (or repolarization) of a particular area of the heart.
Atrial fibrillation a. Triggers p. veins b. Sustainer left atrium enlarged fibrosed
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Atrial Fibrilation
Rate
Varies, ventricular response can be fast or slow
P-P Ratio
Chaotic atrial activity
R-R Ratio
Irregularly irregular
P wave
No discernable p-waves
P:QRS Ratio
None
PR interval
None
QRS Width
Normal, but can have aberrant (wide) complexes
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Is Atrial Fibrillation Important? • 2.5 million Americans with Atrial Fib • 88,000 deaths per year • $16 billion dollars cost to health care per year
Estimated Number of Atrial Fib Cases by 2030 • A) 3 million • B) 5 million • C) 7 million
Atrial fibrillation treatment
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Atrial fibrillation
April March 2010: 2010: 1,980,000 hits March 2011: 2,550,000 hits January 2012: 9,500,000 hits
Stroke Prevention in Atrial Fibrillation -
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Background • 30% of ischemic strokes are of unknown mechanism (cryptogenic stroke) • Detection of AF usually prompts long-term anticoagulation instead of antiplatelet therapy • Optimal monitoring duration to detect AF is currently undetermined
Objectives of CRYSTAL AF • To assess whether a long-term monitoring strategy with an insertable cardiac monitor (ICM) is superior to standard medical care for the detection of AF in patients with a cryptogenic stroke at 6 months (primary end point) and 12 months follow-up (secondary end point) • Determine the proportion of patients with cryptogenic stroke that have underlying AF.
Comparison of Monitoring Strategies Continuous Monitoring Arm: Insertion of REVEAL® XT
Standard Monitoring Arm
Reveal LINQ InsertionAnimation-hi-res.mp4
Cardiac monitoring performed Minimally invasive outpatient procedure according Local anesthetic and no leads or to local standards, after mandated fluoroscopy testing completed 15-30 minute procedure Symptoms consistent with AF Device can be followed Revealremotely LINQ InsertionAnimation-hi-res.mp4 were evaluated by study MRI conditional physicians 3 year device longevity
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Reveal LINQ InsertionAnimation-hi-res.mp4
Primary Endpoint: Detection of AF at 6 months ICM finds 6x more patients with AF
Rate of detection in ICM arm was 8.4% vs 1.4% in control arm
6 Month Endpoints ICM
Control
Median time from randomization to AF Detection
41 days
32 days
Patients found to have AF
19
3
% Asymptomatic Episodes
74%
33%
Oral Anticoagulation (OAC) Usage, overall
10.1%
4.6%
OAC use in patients with detected AF
94.7%
66.7%
Recurrent Stroke/TIA
5.2%
8.6%
Proportion of patients with AF ≥ 6 minutes on one day
93.8%
N/A
Tests required to detect AF
Automatic AF detection
88 ECGs 20 24-hour Holters 1 event recorder
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36 Month Data ICM
Control
Median time from randomization to AF Detection
252 days
72 days
Patients found to have AF
42
5
% Asymptomatic Episodes
81%
40%
Oral Anticoagulation (OAC) Usage, overall
38.5%
8.3%
OAC use in patients with detected AF
90%
80%
Recurrent Stroke/TIA
11.1%
12.7%
Proportion of patients with AF ≥ 6 minutes on one day
94.9%
N/A
Tests required to detect AF
Automatic AF detection
202 ECGs, 52 Holter Monitors, 1 Event Recorder
Conclusions Continuous monitoring with Reveal ICM is superior to standard medical care for the detection of AF in patients with a cryptogenic stroke. The study demonstrated that: 1. Continuous monitoring detected over 7 times more patients with AF at the 12-month end point. 2. When followed for 3 years, 30% of patients in the ICM arm were found to have AF, and only 3% in the Standard Monitoring arm. 3. Short-term monitoring is not sufficient, as the median time to AF detection over 12 months of follow-up was 84 days. 4. 97% of patients who had AF detected were prescribed OAC.
Atrial Fibrillation Update 2015 1. Rate control vs. Rhythm control 2. Who requires anticoagulants and which ones? 3. What is the role of atrial fibrillation ablation?
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Theoretical Benefit of Rhythm Control • • • • • • •
Improved hemodynamics Cardiomyopathy Relief of symptoms Improved exercise tolerance Reduced risk of stroke ? Avoidance of anticoagulants ? more on this later
AFFIRM : 5 Year Outcomes Survival
Rhythm Control
Rate Control
1 year
96%
96%
3 year
87%
89%
5 year
76%
79% p = 0.058
NO Difference : death, disabling stroke, major bleed, or cardiac arrest Sinus rhythm maintained in only 63% of rhythm control group NEJM 2002;347:1825
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AFFIRM Trial • No survival advantage to rhythm control. • Rhythm control patients were more likely to be hospitilized with adverse drug effects. • Both groups had similar stroke risk (1% per yr) – Majority of strokes when warfarin stopped or INR subtherapeutic – Warfarin required long term even if sinus rhythm restored
• Torsades, bradycardic arrest more common with rhythm control. • Typical patient: 69 yo man, no symptoms
Stroke Prevention in Atrial Fibrillation -Mortality in Rate vs. Rhythm Control Patients -The AFFIRM Study p Value Sinus Rhythm
75 - 1 pt Diabetes - 1pt Stroke or TIA - 2 pts
– 0 points – low risk (1.2-3.0 strokes per 100 patient years) – 1-2 points – moderate risk (2.8-4.0 strokes per 100 patient years) – > 3 points – high risk (5.9-18.2 strokes per 100 patient years)
How do we determine stroke risk ? • CHADS2 (Gage, et al.: JAMA 2001) – – – – –
Congestive heart failure - 1pt Hypertension - 1pt Age > 75 - 1 pt Diabetes - 1pt Stroke or TIA - 2 pts
– 0 points – low risk (1.2-3.0 strokes per 100 patient years) – 1-2 points – moderate risk (2.8-4.0 strokes per 100 patient years) – > 3 points – high risk (5.9-18.2 strokes per 100 patient years)
Lip Y, et al. Chest 2010, 137(2):263
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Lip Y, et al. Chest 2010, 137(2):263
CHADS2 vs. CHA2DS2VASc • CHADS2 score 0: 1.4% events • CHA2DS2-VASc 0: 0 events • CHA2DS2-VASc score 1: 0.6% events • CHA2DS2-VASc score 2: 1.6% events
Stroke Risk in AF Rises With CHADS2 Score
Stroke Rate (% per year)
20
18.2
15
12.5 10
8.5 5.9
5
1.9 0
0 n=120
2.8
1 n=463
4.0
2 n=523
3 n=337
4 n=220
5 n=65
6 n=5
CHADS2 Score
♦ Adjusted stroke rate was derived from multivariate analysis assuming no use of aspirin 42 Fuster V et al. J Am Coll Cardiol. 2011;57(11):e101-e198.
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Stroke Prevention in Atrial Fibrillation -Limitations of Warfarin Therapy in Atrial Fibrillation -Narrow Therapeutic Window Target INR 80 Events / 1000 patient years
Ischaemic stroke Intracranial haemorrhage
(2.0-3.0)
The anticoagulant effect of vitamin K antagonists are optimized when therapeutic doses are maintained within a very narrow range
60
40
20
0 4.5
International Normalised Ratio (INR)
Stroke Prevention in Atrial Fibrillation -Limitations of Warfarin Therapy in Atrial Fibrillation
No warfarin 65%
INR Above Target 6% INR at Target 15%
Subtherapeutic INR 13%
• Arch Intern Med 2000; 160: 967.
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Meta-Analysis to Assess the Quality of Warfarin Control in AF in the United States In the United States, AF patients spend only about one-half the time within therapeutic INR. Anticoagulation clinic services are associated with somewhat better INR control compared with standard community care. 55% therapeutic range, “coumadin clinc” 11% better contol
Stroke Prevention in Atrial Fibrillation -Limitations of Warfarin Therapy in Atrial Fibrillation -2o Prevention of Strokes in Patients with A Fib
INR at Target 18%
No warfarin 43%
Subtherapeutic INR 39%
• Analyzed 323 patients with a second ischemic stroke who had known •
atrial fibrillation at the time of their first stroke, and who had no known contraindications to anticoagulation Stroke 2009; 40: 235-40.
New Anticoagulation Agents Dabigatran
Warfarin
Rivaroxaban
Warfarin
Apixaban
Warfarin
Stroke
1.11%
1.69%
1.7%
2.2%
1.27%
1.6%
Major Bleed
3.11%
3.36%
3.6%
3.4%
2.13%
3.09%
HS
0.1%
Mortality 3.64%
0.38%
0.5%
0.7%
0.24%
0.47%
4.13%
4.9%
4.5%
3.52%
3.94%
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Comparision of New Agents Thromb Haemost 2012(3):476-84 • Odd ratio of stroke Rivaroxaban vs Dabigatran 1.35 (p =0.04). • Odd ratio of bleeding Apixaban vs Dabigatran 0.74 (p=0.004). • Odd ratio of bleeding Apixaban vs Rivaroxaban 0.68 (p
