Effect of Chronic Kidney Disease on 5-Year Outcome in Patients With Heart Failure and Secondary Mitral Regurgitation Undergoing Percutaneous MitraClip Insertion

: Chronic kidney disease (CKD) is strongly related to outcomes in cardiovascular diseases. Limited data are available regarding the independent prognostic role of CKD after transcatheter mitral valve repair with MitraClip. We sought to evaluate the real impact of CKD in a large series of patients with heart failure (HF) and secondary mitral regurgitation (SMR) who underwent MitraClip treatment. The study included 565 patients with severe SMR from a multicenter international registry. Patients were stratified into 3 groups according to estimated glomerular filtration rate (eGFR) assessment before MitraClip implantation: normal eGFR (≥60 ml/min/1.73 m2) (n = 196), mild-to-moderate CKD (30 to 59 ml/min/1.73 m2) (n = 267), and severe CKD (<30 ml/min/1.73 m2) (n = 102). The primary end point was a composite of overall death and the first rehospitalization for HF, the secondary end points were overall death, cardiac death, and first rehospitalization for HF. CKD was present in about 2/3 of patients. At 5-year Kaplan-Meier analysis, primary clinical end point occurred in 60% of patients with normal eGFR, compared with 73% cases in patients with mild-to-moderate CKD and 91% in patients with severe CKD (p <0.001). Long-term overall death rate significantly decreased with increasing eGFR, and cardiac death and rehospitalization for HF rates. Multivariate Cox regression analysis identified severe CKD as the strongest independent predictor of adverse outcome (hazard ratio 2.136, 95% confidence interval 1.164 to 3.918, p = 0.014). In conclusion, CKD affected about 2/3 of patients who underwent MitraClip treatment for severe SMR, and it was a strong and independent predictor of 5-year adverse outcomes.