Abstract 4363188: Impact of Atrial Fibrillation in Patients with Severe Mitral Regurgitation Undergoing Transcatheter Edge-To-Edge Repair

Background: Atrial fibrillation (AF) and mitral regurgitation (MR) are closely linked, and one may worsen the other. Objectives: To investigate the impact of baseline AF in patients with MR undergoing transcatheter edge-to-edge repair (M-TEER). Methods: One-hundred-fifty-six consecutive patients with symptomatic heart failure (HF) undergoing M-TEER for severe MR were studied. The primary endpoint was the composite outcome of death or HF hospitalization (HFH). Transthoracic echocardiograms were performed at baseline and follow-up. Results: Mean age was 80.8±8.8 years and 82 (52.6%) patients were female. MR etiology was primary in 69 (44.2%) and secondary in 87 (55.8%) patients. Atrial fibrillation or atrial flutter (AF) was present in 59 (37.8%) patients at baseline. M-TEER was successful (≤2+ MR) in 58 (98.3%) and 94 (96.9%) patients with and without AF respectively (p=0.59). During median 12.5 months follow-up, the primary endpoint occurred in 64 patients (2-year Kaplan-Meier estimated rate 41.0%), including death in 16 patients (10.3%) and HFH in 57 patients (36.5%). Baseline AF remained a significant independent predictor of death or HFH (aHR 2.03, 95% CI 1.12-3.69, p=0.02). Left ventricular end-diastolic volume, left atrial volume and right ventricular systolic pressure decreased during follow-up among patients in sinus rhythm but not among those in AF. AF was associated with an increased risk of severe MR recurrence (18.6% vs. 8.2%, p=0.05). Conclusion: In patients with HF and severe MR treated with M-TEER, baseline AF was associated with impaired right and left heart remodeling, more frequent MR recurrence, and more than doubling of the 2-year risk of death or HFH.