Surgical strategy and outcomes for atrial functional mitral regurgitation: All functional mitral regurgitation is not the same!

Abstract

Objective

Functional mitral regurgitation (FMR) is a cardiac pathology that causes the mitral valve to malfunction, leading to MR. The optimal strategy for FMR remains unclear, and FMR outcomes are poor. All etiologies of FMR may not be the same, and subdividing between FMR caused by atrial (AFMR) vs. ventricular (VFMR) pathology may be important. Here, we present outcomes of patients with AFMR to define this "new" population.

Methods

Patients undergoing mitral valve repair (MVr) for MR from 2000-2020 were reviewed. Patients with degenerative/myxomatous disease, ejection fraction <50% (VFMR), and miscellaneous etiologies including endocarditis and rheumatic disease were excluded to isolate a population of "pure" AFMR patients. Descriptive characteristics and outcomes data were analyzed.

Results

Among 123 total AFMR patients, mean preoperative left atrial dimensions were enlarged to 4.9 [95% confidence interval, 4.7-5.0] cm, while mean preoperative left ventricular diastolic dimensions remained near normal at 5.0 [95% confidence interval, 4.9-5.2] cm. Preoperative atrial fibrillation (AF) was noted in 61% (74/123). Echocardiogram was performed in 58% (71/123) of patients at a median of 569 (interquartile range, 75-1782) days after surgery. Of those, 72% (51/71) had trivial or no MR, 22% (16/71) mild and only 6% (4/71) moderate or greater MR. Only 1.6% (2/123) required redo mitral valve reoperation. Estimated 5-year survival was 74%.

Conclusions

Patients with AFMR do well following Mvr using an annuloplasty ring, with low rates of reoperation, mortality, and recurrence of MR. Mitral annuloplasty should be considered the surgical therapy of choice for AFMR.