Mitral valve repair versus replacement with extensive annular calcification: a systematic review and meta-analysis

Background: Mitral annular calcification (MAC) represents an important risk factor in mitral valve (MV) surgery. Despite several procedures have been described, no surgical treatment of choice has been yet established. Materials and Methods: A systematic review of the literature and meta-analysis on patients undergoing MV surgery associated to MAC was performed. The meta-analysis primary endpoints were 30-day mortality and late overall and cardiac-related mortality. Secondary endpoints were early reintervention, re-exploration for bleeding, postoperative pacemaker implantation, cerebrovascular accident, atrioventricular groove rupture, acute myocardial infarction and late recurrences of mitral regurgitation (MR) or paravalvular leak and reintervention. Primary and secondary endpoints were also evaluated in the subgroup analysis between MV repair and replacement surgery. Meta-regression was used to analyze the influence of decalcification and annular reconstruction on endpoints. Results: Among 1429 papers, 25 papers studying 1327 patients were included. In the pooled analysis, the 30-day mortality event rate was 2.89% (95%Confidence Interval [CI], 1.48%-5.57%) and 7.72% (95%CI, 2.95%-18.71%) for MV repair and replacement respectively. At mid-term follow-up, MV repair revealed a significantly lower incidence rate (IR) of death compared to MV replacement (p=0.043), with a trend of higher reoperation IR compared to replacement (p=0.051) and a trend of higher recurrent MR2+ in MV repair (p=0.071). Annular reconstruction was associated with a significant increase in re-exploration for bleeding at univariate analysis, but not at the multivariate meta-regression. Conclusions: The current meta-analysis suggests that MV repair in MAC patients may provide better short and mid-term survival outcomes when compared to replacement.