A Randomised Controlled Trial of Catheter Ablation Versus Medical Treatment of Atrial Fibrillation in Heart Failure (THE CAMTAF TRIAL)
Does restoration of sinus rhythm by catheter ablation improve outcomes in patients with atrial fibrillation (AF) and congestive heart failure (CHF)?
Fifty patients were recruited to participate in this study (THE CAMTAF TRIAL). Patients with persistent AF and CHF (ejection fraction [EF] <50%) were randomized to catheter ablation versus medical therapy. Prior to randomization, all patients underwent optimization of rate-control and CHF therapy. The ablation protocol consisted of pulmonary vein isolation, biatrial defragmentation, and linear ablation. The primary endpoint was the left ventricular EF at 6 months.
Freedom from AF was achieved in 21/26 patients (81%) in the ablation arm without antiarrhythmic drugs (AADs) at 6 months after a mean of 1.7 procedures per patient. Procedural complications included one instance of stroke and tamponade. The mean EF improved from 32% to 40% (p = 0.015) in the ablation arm, and was unchanged among controls. There was an improvement in the peak oxygen consumption, and symptoms in the ablation group only.
A rhythm-control strategy consisting of catheter ablation restored sinus rhythm in most patients with persistent AF and systolic HF, and was associated with improvements in left ventricular performance and functional capacity.
A sinus rhythm strategy using AADs has not been shown to improve outcomes in patients with AF and CHF. The positive results of the current study are likely related to the fact that catheter ablation restores sinus rhythm more effectively than AADs, and that it does so without proarrhythmia and end-organ toxicity. Since rate control was optimized prior to ablation, this makes it unlikely that ventricular dysfunction was due to tachycardia. The results of this small study have possibly far-reaching implications, such as reducing CHF-related hospitalizations, candidacy for implantable defibrillator therapy, and perhaps overall mortality. Whether sinus rhythm and its salutatory effects will be maintained long-term require additional study. Although these results are possible at experienced centers, the complexity of the ablation procedure(s) for persistent AF in this population makes it difficult to generalize these findings.
Clinical Topics: Arrhythmias and Clinical EP, Heart Failure and Cardiomyopathies, Implantable Devices, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias, Acute Heart Failure
Keywords: Stroke, Ventricular Dysfunction, Oxygen Consumption, Pulmonary Veins, Heart Failure, Catheter Ablation, Defibrillators, Implantable, Tachycardia
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