Effect of Renal Impairment on Clinical Outcomes After Mitral Valve Transcatheter Edge-to-Edge Repair

Background: Renal impairment is associated with poor clinical outcomes in patients with cardiovascular diseases. Some studies have revealed the impact of renal impairment on the clinical outcomes of patients who underwent mitral valve transcatheter edge-to-edge repair (M-TEER). However, limited data are available regarding the impact of baseline renal impairment after M-TEER in Asian-Pacific patients with heart failure and severe mitral regurgitation. Objectives: This study sought to examine the effect of renal impairment on clinical outcomes after M-TEER using a large-scale nationwide registry in Japan. Methods: A total of 2,150 patients enrolled in the OCEAN-Mitral (Optimized Catheter Valvular Intervention) registry were divided into 3 groups according to the estimated glomerular filtration rate (eGFR) before M-TEER: normal eGFR (≥60 mL/min/1.73 m²) (n = 291), renal impairment (<60 mL/min/1.73 m²) (n = 1,746), and dialysis (n = 113). The impact of renal impairment and dialysis on major adverse cardiovascular events (MACE) (a composite of all-cause death and hospitalization for heart failure) was examined. Results: Kaplan-Meier analysis revealed that the renal impairment and dialysis groups had a significantly higher incidence of MACE (survival rates at 2 years: normal eGFR, 74.2% [95% CI: 66.9%-80.1%] vs renal impairment, 63.9% [95% CI: 61.0%-66.6%] vs dialysis, 50.9% [95% CI: 38.2%-62.2%]; P < 0.001). Multivariate Cox regression analysis identified dialysis as the strongest independent predictor of MACE (HR: 1.95; 95% CI: 1.33-2.85; P < 0.001). Conclusions: Renal impairment was associated with an increased incidence of major adverse events, and dialysis was the strongest independent predictor of poor clinical outcomes after M-TEER in Asian-Pacific patients.