Impact of Residual Functional Mitral Regurgitation After Atrial Fibrillation Ablation on Clinical Outcomes in Patients With Left Ventricular Systolic Dysfunction

doi:10.1016/j.amjcard.2022.12.024

The American Journal of Cardiology

Volume 191, 15 March 2023, Pages 66-75

https://doi.org/10.1016/j.amjcard.2022.12.024 Get rights and content

Functional mitral regurgitation (FMR) negatively impacts the prognosis in patients with atrial fibrillation (AF) and reduced left ventricular (LV) ejection fraction (LVEF). Although structural reverse remodeling after AF ablation can reduce FMR severity, the prognostic impact of FMR and its evolution remain unclear. Of 491 patients with baseline LVEF <50% who underwent first-time AF ablation, 134 patients (27%) had grade 2 to 4 FMR at baseline. Among them, 88 patients (66%) exhibited FMR improvement to grade 0 to 1 FMR 6 months after AF ablation. Conversely, among 357 with baseline grade 0 to 1 FMR, 13 patients (3.6%) exhibited FMR worsening to grade 2 to 4 FMR despite AF ablation. Assessment with multidetector computed tomography revealed that an increase in the left atrial emptying fraction (odds ratio 3.55 per 10% increase; 95% confidence interval 2.12 to 5.95) and a reduction in the LV end-diastolic volume index (1.35 per 10-ml/m² decrease; 1.04 to 1.76) were identified as contributors to the FMR improvement. During a follow-up of 43 months, patients with postprocedural grade 2 to 4 FMR more frequently experienced hospitalizations for heart failure or cardiovascular death than those with grade 0 to 1 FMR (30.5% vs 4.6%, log-rank p <0.001). An age-adjusted multivariate Cox regression analysis including baseline and postprocedural FMR revealed that postprocedural grade 2 to 4 FMR (hazard ratio, 3.24; 95% confidence interval 1.43 to 7.35) was significantly associated with unfavorable events. In conclusion, AF ablation modified and often improved FMR severity in patients with reduced LVEF. Residual grade 2 to 4 FMR 6 months after AF ablation was associated with a poor prognosis.

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Methods

This single-center study retrospectively evaluated 4,122 consecutive patients who underwent first-time CA of AF between January 2012 and September 2021 at Sakurabashi Watanabe Hospital, Osaka, Japan. Of the 521 recruited patients with a baseline LVEF of <50%, we excluded a total of 30 patients with a history of surgical mitral valve treatment (n = 12), presence of severe degenerative mitral valve disease (n = 5), incomplete echocardiogram data (n = 5), or a follow-up period of <6 months

Results

The baseline characteristics of the study patients are described in Table 1. The etiology of the LV systolic dysfunction was nonischemic in 441 patients (90%). Among them, 397 had no apparent structural heart disease. A successful PVI was achieved in all patients. There were no occurrences of cardiac tamponade, strokes, or atrial-esophageal fistulae (Supplementary Table 1). Patients with baseline grade 2 to 4 FMR had a more unfavorable background than those with baseline grade 0 to 1 FMR. The

Discussion

The principal findings of this study were as follows: (1) In patients with LVEF of <50% eligible for CA of AF, 2/3 of the patients exhibited improvements in the FMR from grade 2 to 4 to grade 0 to 1 after CA. (2) Both the LA and LV structural and functional reverse remodeling were associated with an improvement in the FMR, and an increase in the LAEF and a reduction in the LVEDVI were the primary contributors in this study population. (3) Residual grade 2 to 4 FMR 6 months after CA was

Disclosures

Koichi Inoue has received honoraria from Johnson and Johnson KK, and Medtronic, Inc. Nobuaki Tanaka has received honoraria from Johnson and Johnson. The other authors have no conflicts of interest to declare.

Acknowledgment

The authors would like to thank the nursing staff, clinical engineers, radiological technologists, and office administrators of Sakurabashi Watanabe Hospital for their support in conducting this study. We also thank Mr. John Martin for his linguistic assistance with this manuscript.