Impact of preoperative mitral regurgitation on LVAD patients: propensity-score matched analysis of the EUROMACS dataset

Introduction: Mitral regurgitation (MR) is frequently observed in patients undergoing left ventricular assist device (LVAD) implantation. We investigated the impact of preoperative MR on LVAD patients. Methods: A retrospective propensity score-matched analysis of adult patients enrolled in the EUROMACS registry between 01/01/2011 and 30/11/2021 was performed. Patients were divided into two groups according to the grade of preoperative MR: none-to-mild (MR 0-II) or moderate-to-severe (MR III-IV). Results: Following 1:1 propensity score matching, each group consisted of 914 patients. Incidence of postoperative temporary right ventricular support, reoperation for bleeding, and dialysis was similar. MR III-IV demonstrated shorter median ICU stay (14 d [6; 27.8] vs 10 d [5; 22], p = 0.004) and ventilation time (72 h [22, 320] vs 31 h [18, 150], p < 0.001).Mortality was lower for MR III-IV patients (SHR 0.66, 95% CI: 0.59-0.73, p < 0.001). The 1-year survival was 68.1% (95% CI: 65.1-71.3%) in MR 0-II and 75% (95% CI: 72.1-78%) in MR III-IV. A lower incidence of total complications (OR 0.93 [0.89-0.98], p = 0.003) and trend towards a lower risk of neurological dysfunction (SHR 0.79; 95% CI: 0.61-1.01, p = 0.063) and sustained ventricular tachycardia (OR 0.93 [0.54-1.03], p = 0.074) were demonstrated for MR III-IV. The risk of fatal stroke and pump thrombosis was similar. Conclusion: Moderate-to-severe MR in patients undergoing LVAD implantation is associated with better mid-term survival and lower incidence of total major adverse events and complications. The incidence of severe postoperative complications including fatal stroke and device thrombosis was similar.