Effect of oral tolvaptan for 1 year in patients with functional mitral regurgitation

The effect of the oral selective vasopressin V2-receptor antagonist tolvaptan for chronic phase therapy on patients with FMR remains unclear. We aimed to determine the efficacy of oral tolvaptan in patients with significant functional mitral regurgitation (FMR) to reduce the mortality and rehospitalization due to worsening heart failure (HF). We enrolled 219 patients (mean age 76 ± 9 years, 59.4% men) who were admitted at our hospital due to congestive HF during different two 1-year periods. The patients were divided into 2 groups: those who had significant FMR (MR ≥ grade 2 [n = 76]) and those who did not (MR < grade 2 [n = 143]) at discharge. The patients were further divided into a study group that received tolvaptan during follow-up and a control group that did not receive tolvaptan. We used an inverse probability of treatment weighting method with the primary end point defined as overall all-cause mortality and rehospitalization due to worsening HF within 1 year. Of the 76 patients with significant FMR at discharge, 2 of 20 (10%) who were administered tolvaptan died and 8 (40%) were readmitted to a hospital. Of the 56 patients who did not receive tolvaptan, 2 (3.5%) died and 18 (27.5%) required rehospitalization. After multiple adjustments, there were no significant differences for overall survival and rehospitalization between the groups (log-rank p = 0.700 and 0.510, respectively). Our results suggest that oral tolvaptan administration in addition to conventional diuretics had less impact on outcomes in patients with significant FMR.