Persistent atrial fibrillation after radiofrequency ablation: considerations in treating rheumatic mitral valve disease patients

Abstract

Atrial fibrillation (AF) in patients with rheumatic heart disease (RHD) results from hemodynamic consequences of valvular or myocardial heart disease and from direct tissue injury of the atrial myocardium by the underlying inflammatory process [1]. About 60% of patients with rheumatic valve disease develop AF. Several studies have clearly demonstrated a low probability of sinus rhythm recovery in patients with preoperative AF undergoing valve surgery for RHD [2,3]. Atrial fibrillation persistence is associated with worse clinical outcomes that include functional status, exercise capacity, quality of life and overall survival. A retrospective analysis was performed on a total of 793 patients who underwent mitral valve replacement with or without tricuspid valve repair [4]. At a mean follow-up of 8.6 ± 2.4 years of patients with preoperative AF, survival was 88.7%, compared with 96.6% in patients with preoperative sinus rhythm (p = 0.002). Several technical approaches and different energy sources have been employed to restore sinus rhythm in patients undergoing valve surgery. The proper way to verify success after an AF ablation procedure is controversial; continuous rhythm monitoring should be the gold standard of follow-up, but very few studies use it, thus results reported in literature are not easily comparable. It is conceivable that in patients followed with periodic ECG evaluation asymptomatic AF recurrences may occur, thus the true effectiveness might remain unknown. The surgical results of the maze procedure for AF associated with rheumatic mitral valve disease have been known to be less effective than for lone or nonrheumatic AF [5]. Preoperative patients characteristics (age, NYHA functional class at the time of surgery, type of prosthetic valve, proportion of paroxysmal and persistent AF, duration of the arrhythmia), concomitant surgical procedures (including vagal denervation) other than the modalities of success rate evaluation at followup, may explain the large variability (55–80%) of results reported in literature [6–9]. In a recent paper, our group demonstrated in patients undergoing radiofrequency (RF) ablation associated with mitral valve surgery that an increased left atrial area (HR: 1.07 per unit increase; 95% CI: 1.01–1.13) and rheumatic etiology of valve disease (HR: 4.52; 95% CI: 1.65–12.4) were significantly associated with the risk of persistence of AF at hospital discharge [10]. Less than 20% with atrial diameter greater than 55 mm and rheumatic mitral disease recovered sinus rhythm. At 6-year follow-up persistent sinus rhythm (SR) and overall survival in patients with rheumatic mitral valve disease in comparison with degenerative mitral (mitral valve prolapse) who underwent RF ablation and valve surgery were, respectively, 58 and 64%, and 84 and 90%. Persistent atrial fibrillation after radiofrequency ablation: considerations in treating rheumatic mitral valve disease patients