Chronic mitral regurgitation: Does atrial fibrillation impact outcome in patients managed with medical therapy only?

Abstract

Background: The AHA/ACC guideline recommends surgery for symptomatic chronic severe mitral regurgitation or percutaneous mitral valve repair for high surgical risk or inoperable patients. Although atrial fibrillation (AF) is a known predictor of survival after either of these interventional procedures, its impact on the outcome of patients treated only medically is less well defined. Materials and Methods: This was a retrospective review of adult patients with chronic mitral regurgitation seen at our heart center from August 2014 to December 2017. Results: There were 102 patients, with a mean age of 58.4 ± 15.8 years and 51% were males. Major comorbidities were AF (58.8%), hypertension (HTN) (53.9%), pulmonary HTN (18.6%), and diabetes mellitus (10.8%). Sixty-seven (65.7%) patients had primary and 35 (34.3%) had secondary mitral regurgitation. Eighty-eight (86.3%) patients were in New York Heart Association Class 3/4, 92 (90.2%) in AHA/ACC Stages C/D, and 70 (68.6%) had left ventricular (LV) dysfunction with ejection fraction (EF) <60. Patients were subdivided into Group 1 – 60 (58.8%) patients with AF and Group 2 – 42 (41.2%) patients without AF. AF frequency was higher with primary or degenerative mitral regurgitation (PMR) versus secondary mitral regurgitation (SMR), 75% versus 25%, P = 0.031, whereas HTN was higher in SMR versus PMR, 77.1% versus 41.8%, P = 0.001. Four patients underwent mitral valve replacement and two patients implantable cardioverter defibrillator. All patients were treated with the AHA/ACC guideline-directed medical therapy (GDMT). All-cause mortality for Groups 1 and 2 was 25% and 14.3%, respectively, odds ratio was 2.0, and 95% confidence interval was 0.705–5.677, P = 0.285. Overall, Kaplan–Meier survival at 30 months was 63%, and log-rank analysis survival was 56% and 79% for Groups 1 and 2, respectively, P = 0.345. Conclusion: In a cohort of patients with chronic mitral regurgitation treated only medically with GDMT in a low-resource country, all-cause mortality and intermediate survival were comparable between AF and non AF patients.