Predictors of mortality in ischaemic versus non-ischaemic functional mitral regurgitation after successful transcatheter mitral valve repair using MitraClip: results from two high-volume centres

Transcatheter edge-to-edge mitral valve repair using the MitraClip has been widely performed in surgical high-risk patients with reduced left ventricular systolic function and severe functional mitral regurgitation (FMR). Ischaemic heart disease is the leading aetiology of heart disease worldwide. We aimed to assess the clinical implications of ischaemic aetiology in patients with severe FMR who underwent MitraClip implantation. From two high-volume centres in Germany, we retrospectively compared the clinical outcomes and clinical predictors of all-cause mortality after MitraClip implantation in patients with ischaemic (I-FMR) and non-ischaemic FMR (NI-FMR). In the overall FMR cohort (n = 575), there were 336 (58%) patients with I-FMR and 239 (42%) with NI-FMR. There was no significant difference in survival between the two groups (log-rank p = 0.78). In a multivariable Cox regression analysis of all-cause mortality, different predictors were observed for either group. In I-FMR patients, decreasing tricuspid annular systolic excursion [adjusted hazard ratio (HRadj) 1.06, 95% confidence interval (95% CI) 1.01–1.14 /1 mm, p = 0.028] and increasing logistic EuroSCORE (HRadj 1.02, 95% CI 1.00–1.03, p = 0.037) were independent predictors, whereas in NI-FMR patients, NT-pro BNP (HRadj 1.05, 95% CI 1.02–1.08, p = 0.001) and age (HRadj 1.06, 95% CI 1.01–1.11, p = 0.013) were independently predictive of mortality. Despite the similar survival between ischaemic and non-ischaemic FMR, different predictors of all-cause mortality were demonstrated. Further clinical studies are mandated to focus on each FMR subgroup with stratification by ischaemic origin.