RESUMEN
Objective: The effect of mitral valve (MV) surgery on the natural history of ventricular arrhythmia (VA) in patients with arrhythmic MV prolapse remains unknown. We sought to evaluate the cumulative incidence of VA at 1 year after surgical mitral repair. Methods: A retrospective review of progressively captured data identified 204 consecutive patients who underwent elective MV repair for significant degenerative mitral regurgitation as a first-time cardiovascular intervention in a quaternary reference center between January 2018 and December 2020. A subset of 62 consecutive patients with diagnosed arrhythmic MV prolapse was further evaluated for recurrent VA after MV repair. Results: The median age was 62 years (range, 27-77 years) and 26 of 62 (41.9%) were female. The median time from initial mitral regurgitation/MV prolaspe diagnosis-to-referral was 13.8 years (interquartile range [IQR], 5.4-25) and from VA diagnosis-to-referral was 8 years (IQR, 3-10.6). Using the Lown-Wolf classification, complex VA (Lown grade ≥3) was identified in 36 of 62 patients (58%) at baseline, whereas 8 of 62 (13%) had a cardioverter/defibrillator implanted for primary (4/8) or secondary (4/8) prevention. Left ventricular myocardial scar was confirmed in 23 of 34 (68%) of patients scanned at baseline. The prevailing valve phenotype was bileaflet Barlow (59/62; 95.2%). All patients underwent surgical MV repair by the same team. Surgical repair was stabilized with an annuloplasty prosthesis (median size 36 mm [IQR, 34-38]). Concomitant procedures included tricuspid valve repair (51/62; 82.3%), cryo-maze ± left atrial appendage exclusion (14/62, 23%), and endocardial cryoablation of VA ectopy (4/62; 6.5%). The 30-day and 1-year freedom from recurrent VA were 98.4% and 75.9%, respectively. Absent VA after mitral repair was uniformly observed in patients with minor VA at baseline. Absent VA after mitral repair was uniformly observed in patients with minor VA preoperatively. Complex baseline VA was the strongest predictor of recurrent VA (hazard ratio, 10.8; 95% confidence interval, 1.4-84.2; P = .024), irrespective of myocardial fibrosis. Conclusions: In a series of 62 consecutive patients operated electively for arrhythmic mitral prolapse, VA remained undetected in 75.9% of patients at 1 year. Freedom from recurrent VA was greater among patients without complex VA preoperatively, whereas baseline Lown grade ≥3 was the strongest independent risk factor for recurrent VA at 1 year. These findings attest to the importance of early recognition and prompt referral of patients with mitral prolapse and progressive VA to specialty interdisciplinary care.
RESUMEN
PURPOSE OF REVIEW: Surgical mitral valve repair is considered superior to replacement to treat primary mitral regurgitation. However, the heterogeneity of cohorts and the lack of consideration of confounding in the published literature raise potential biases. The aim of this study was to pool all available matched data comparing outcomes of mitral valve repair and replacement in the setting of primary mitral regurgitation. RECENT FINDINGS: We searched Medline, Embase and the Cochrane Library Central Register of Controlled Trials to identify propensity-matched studies or reports with multivariable adjustment comparing repair and replacement in patients with primary mitral regurgitation. The primary outcome was all-cause mortality. DerSimonian and Laird random effects were used to perform the meta-analysis. Eight observational studies were selected including 4599 patients (3064 mitral repairs and 1535 replacements). Mean age ranged from 62 to 69 years, and the mean follow-up duration ranged between 3 and 9 years. Replacement was associated with an increased risk of long-term all-cause mortality compared to repair (HR of 1.68, 95% confidence interval 1.35-2.09, p < 0.001, τ2 = 0.03). Surgical era and atrial fibrillation impacted the risk of mortality but not mitral anatomy. Neither repair nor replacement impacted significantly on the risk of re-operation after mitral surgery (HR 1.18, 95% CI 0.85-1.63, p = 0.33, τ2 < 0.01). Mitral valve replacement is possibly associated with higher long-term mortality than mitral valve repair in primary mitral regurgitation but often used as a bailout option in more complex anatomy. Despite this observation, both techniques have similar risk of re-operation.