Devices for Control of Atrial Fibrillation
Joseph G Akar, MD, PhD Associate Professor of Medicine Director, Cardiac Electrophysiology Laboratory
AF in Heart Failure
All-cause mortality by baseline atrial fibrillation
Mortality following new onset AF in patients with sinus rhythm at baseline
Eur Heart J 2005; 26:1303-1308
Atrial Fibrillation and Heart Failure: The age-old question
AF
CHF
Principles of Management
1
2
3
Circulation 2012;125:945-957
Principles of Rate Control in AF: The Good, The Bad, the and Ugly
Principles of Rate Control for AF •The Good: Beta Blockers •Improve HF morbidity and mortality •Prevent SCD in HF •Rate control prevents LVEF deterioration •Cannot use in decompensated HF
•The Bad: Digoxin •Very poor rate control agent •Does not improve AF •Risk of toxicity •Positive inotropic effect N Engl J Med 2008;358:2667-77
•The Ugly: AVJ ablation/permanent pacer •Excellent in rate control •Risk of pacemaker/pacemaker dependency •Risk of HF
MOST Trial
MOST Trial
MADIT II Trial
DAVID Trial
Attempt to reduce RV pacing as best possible, however 100% pacing may not be avoidable such as in cases of AVJ ablation for control of AF
The Dilemma of Ablate and Pace AF may prevent HF response to pacing BUT Controlling AF by pacing may worsen HF
Ablate and Pace
AF
CHF
Ablate and Pace
AF
CHF
AF
CRT
CHF
Does controlling AF by pacing worsen HF?
Medical Management vs AVJ Ablation/RV pacing
Change in LVEF
Chattejee NA et al. Circulation: Arrhythmia and Electrophysiology. 2012; 5: 68-76
Medical Management vs AVJ Ablation/CRT
All-cause mortality
Cardiovascular mortality
Ganesan AN et al. J Am Coll Cardiol. 2012;59(8):719-726
Conclusions •Ablate and pace is more effective that pharmacological therapy for control of AF •Controlling AF by AVJ ablation/pacing does not worsen HF •In patients with normal LVEF, it is reasonable to attempt RV pacing only but keep a close eye on the LVEF •In patients with LV dysfunction it is more prudent to use CRT
Does AF Worsen the Response to CRT
AF during CRT causes: •Irregular heart rate •Fusion/pseudofusion •Fast uncontrolled heart rate
Mechanisms of Dyssynchrony in Heart Failure
•Atrioventricular dyssynchrony •Interventricular dyssynchrony •Intraventricular dyssynchrony
Summary of Proposed Mechanisms Cardiac Resynchronization
Intraventricular Synchrony
↑ dP/dt, ↑ EF, ↑ CO (↑ Pulse Pressure) ↓ LVESV
Atrioventricular Synchrony
↓ MR
↓ LA ↑ LV Diastolic Pressure Filling
↓ LVEDV
Reverse Remodeling Yu C-M, Chau E, Sanderson J, et al. Circulation 2002;105:438-445
Interventricular Synchrony
↑ RV Stroke Volume
Proposed Mechanisms: Improved Atrioventricular Synchrony Improved Atrioventricular Synchrony
AF
Optimized AV Delay: ↓ Isovolumic Contraction Time1,2
↓ MR
1,4
↓ LA1 Pressure
↑ LV Diastolic Filling1,3
↓ LVEDV1,4
Yu C-M et al. Circulation 2002;105:438-445 2 Kindermann M et al. Pacing Clin Electrophysiol 1997; 20(I):2453-2462 3 Breithardt O et al. Am Heart J 2002;143:34-44 4 Søgaard P et al. Cardiology 2001;95:173-182 1
Does AF affect CRT?
All cause mortality
Higher mortality in AF patients with CRT did not reach significance
Upadhyay GA et al. J Am Coll Cardiol 2008; 52: 1247-1249
Does AF affect CRT? LVEF
AF: 25.3% to 35.2%
NSR: 24.6% to 33.8% P<0.001
* Calculation method of LVEF was not uniformly reported Upadhyay GA et al. J Am Coll Cardiol 2008; 52: 1247-1249
Does AF affect CRT? NYHA
Patients with AF showed slightly less functional improvement compared to SR (0.84), but was still significant
Upadhyay GA et al. J Am Coll Cardiol 2008; 52: 1247-1249
Does AF affect CRT? Functional Outcomes
6MWD 11.6 m
MLWHF
Upadhyay GA et al. J Am Coll Cardiol 2008; 52: 1247-1249
Conclusions
•The presence of AF does not fully negate CRT response in patients who are otherwise candidates, but may affect mortality benefit •Functional improvement in response to CRT may be diminished due to AF •Patients with AF undergoing CRT must be closely monitored for maximal BiV pacing
Management of AF and CRT Effect of maximizing BiV pacing
Koplan BA et al. J Am Coll Cardiol 2009; 53: 355-360
Management of AF and CRT
Gasparini M et al. Eur Heart J 2008; 29:1644-1652
AF ablation in Heart Failure •Case-control study: 58 pts with CHF (class II-IV) and LVEF < 45% underwent AF ablation •Control group: 58 patients matched for age, sex, AF classification •91% with persistent/permanent AF •Mean LVEF improved 21±13% •Greatest improvement (24±8%) in pts with no structural disease and high rates (tachyinduced)
Hsu L-F et al, N Engl J Med 2004; 351:2373-83
AF Ablation vs AVJ ablation + CRT in CHF
N Engl J Med 2008; 359: 1778-85
Conclusions
•AF control is very important especially in setting of CHF •AVJ/pacer is more effective than pharmacological therapy •Strongly consider CRT for patients with LV dysfunction undergoing AVJ ablation •Strongly consider AVJ ablation for CRT patients with uncontrolled AF •Consider AF ablation for rhythm control when suitable