Variable definitions and treatment approaches for atrial functional mitral regurgitation: A scoping review of the literature

Abstract

Objectives Atrial functional mitral regurgitation (AFMR) is a subtype of functional mitral regurgitation due to longstanding atrial fibrillation (AF) or heart failure with preserved ejection fraction. The variation in AFMR' definition and the common mode of treatment described in the literature remain unknown. Methods We performed a scoping review of studies that surgically treated AFMR to characterize the existing variability in the definition of AFMR, the type of operations performed for AFMR valvulopathy, and the treatment for the chronic AF. We searched Medline, EMBASE, Cochrane Library, Scopus, and Web of Science since their inceptions for studies of patients affected by AFMR and surgically treated for their valvulopathy. Results Twelve studies (n = 494 patients) met eligibility criteria. All studies excluded patients with signs of left ventricular (LV) dysfunction, but the way additional parameters were used to define AFMR at a more granular level varied across studies: nine studies (75%) used the presence of AF to define their AFMR cohorts, with five (41.2%) requiring a history of AF of >1 year; additionally, the threshold values for the LV ejection fraction differed (45%–55%). Isolated mitral annuloplasty was performed in 96.2% of patients. Broad variability was detected in the proportion of patients undergoing the Cox‐Maze procedure (range, 17.8%–79.5%), pulmonary vein isolation (0.0%–66.7%), and left atrial appendage ligation (0.0%–100.0%). Conclusions AFMR remains variably defined in surgical studies, making comparisons across studies difficult. Mitral annuloplasty was most commonly performed. The proportion of AFMR patients undergoing concomitant procedures for AF varied substantially.

Outcomes of transcatheter edge‐to‐edge repair for atrial functional mitral regurgitation: A meta‐analysis of observational studies

“…Recent evidence suggests that the prognosis of MR patients undergoing surgery is different between those with AFMR and VFMR, suggesting that distinguishing the two functional MRs for surgical candidates may have long‐lasting therapeutic implications. Two retrospective studies have found that mitral valve annuloplasty, the preferred surgical strategy to treat AFMR, 36 yielded better clinical outcomes, including long‐term survival in AFMR compared to VFMR 33,37 . While our study did not find any significant differences between AFMR and VFMR with TEER, our long‐term outcome for MR ≤ 2 of 97.1% was comparable to 93%–94% in mitral valve annuloplasty; thus, TEER may be a viable less invasive option for patients who are ineligible for surgery 33,38 .…”

Impact of secondary mitral regurgitation on survival in atrial and ventricular dysfunction

“…Ventricular dysfunction was defined as those with LVEF <55% regardless of atrial dimension or atrial arrhythmia histories. We adopted this definition while recognizing that prior studies have variably defined atrial dysfunction [ 16 ]. LVEF was estimated using 2D or 3D volumetric tracing.…”

Assessing emerging causes of mitral regurgitation: atrial functional mitral regurgitation

“… 88 Mitral valve surgery typically entails restricted ring annuloplasty. 89 A large annular area may impede coaptation unless the ring is significantly undersized. This, however, raises the likelihood of dehiscence and mitral stenosis.…”