Impact of Mitral Regurgitation on Outcomes of Catheter Ablation for AF With Left Ventricular Systolic Dysfunction.

BACKGROUND

Atrial fibrillation (AF) and left ventricular (LV) systolic dysfunction (LVSD) may be associated with function mitral and tricuspid regurgitation (FMR/FTR). Prior studies have largely assessed impact of MR on AF ablation outcomes in the presence of preserved LV ejection fraction.

OBJECTIVES

This study sought to determine the impact of FMR on the outcomes of catheter ablation (CA) in patients with AF and LVSD.

METHODS

We examined baseline clinical characteristics, CA outcomes, and change in echocardiographic parameters (FMR and FTR severity, LV and left atrial [LA] dimensions, LVEF) at baseline and 12 months in individuals with AF and LVSD with at least mild FMR undergoing CA. Patients with primary mitral valve disease were excluded.

RESULTS

235 patients (age 62.8 years,16.2% female, NYHA functional class III (Q1-Q3: II-III)) underwent CA and were categorized by FMR severity at baseline (mild n = 117; moderate/severe n = 118). Baseline characteristics were comparable irrespective of degree of FMR, other than lower LVEF (LVEF 29% [Q1-Q3: 22.8%-35.0%] vs 35% [Q1-Q3: 30.0%-41.0%]; P < 0.001) and increased tricuspid regurgitation in moderate/severe MR (22%) vs mild MR (8%, P < 0.001). LA size did not differ significantly across FMR groups (P = 0.233). At 12 months following CA, recurrent atrial arrhythmia occurred in 101 of 235 (43.0%) including 42.7% in mild vs 43.2% in moderate-to-severe MR (P = 0.940). The severity of FMR did not influence arrhythmia recurrence (OR: 1.15; 95% CI: 0.54-1.86; P = 0.601) nor LV recovery (OR: 1.07; 95% CI: 0.67-1.25; P = 0.153). After CA, 89% of those with significant FMR and 85% with significant FTR exhibited ≥1 grade reduction at 12 months. Change in LV dimensions was associated with MR responders (OR: 0.93; 95% CI: 0.87-0.99; P = 0.022) with a greater reduction in LV size at 12 months in MR improvement (-5.0 (Q1-Q3: -9.3 to -1.0) vs non-improvement -1.0 (Q1-Q3: -5.0 to 2.5), P = 0.004) whereas change in LA size was not (OR: 0.98; 95% CI: 0.97-1.03; P = 0.984).

CONCLUSIONS

In patients with AF and LVSD, the degree of FMR did not impact the success of ablation. There was a significant reduction in FMR and FTR at 12 months following CA. Patients with AF and LVSD should be strongly considered for AF ablation irrespective of the degree of mitral regurgitation.