LAUSR

The Mitraclip is the most established percutaneous mitral valve intervention indicated for severe mitral regurgitation at high or prohibitive surgical risk. Risk stratification plays a critical role in selecting the appropriate treatment modality in high risk valve disease patients but have been rarely studied in this setting. We compared the performance of risk scores at predicting mortality after Mitraclip in this meta-analysis. MEDLINE, Embase and Cochrane databases from 1 January 1980 to 31 December 2018 were searched. Two authors reviewed studies which reported c-statistics of risk models to predict mortality after Mitraclip for inclusion, followed by data extraction and pooled analyses. Amongst 494 articles searched, 47 full-text articles were evaluated, and 4 studies totalling 879 Mitraclip cases were included for analyses. Operative mortality was reported at 3.3–7.4% in three studies, and 1-year mortality 11.2%-13.5% in two studies. C-statistics (95% confidence interval) for operative mortality were EuroSCORE 0.66 (0.57–0.75), EuroSCORE II 0.72 (0.60–0.85) and STS Score 0.64 (0.56–0.73). Respective Peto's odds ratios (95% confidence interval) to assess calibration were EuroSCORE 0.21 (0.14–0.31), EuroSCORE II 0.43 (0.24–0.76) and STS Score 0.36 (0.21–0.61). C-statistics (95% confidence interval) for 1-year mortality were EuroSCORE II 0.64 (0.57–0.70) and STS Score (0.58–0.64). All scores over-estimated operative mortality, and EuroSCORE II had the best moderate discrimination while the other two scores were only modestly prognostic. Development of Mitraclip-specific scores may improve accuracy of risk stratification for this procedure to guide clinical decision-making.