Right Heart Dysfunction and Clinical Outcomes in Patients with Severe Mitral Regurgitation undergoing MitraClip

Background: At present, it is unclear whether right heart dysfunction (RHD) predicts adverse outcomes in patients with severe mitral regurgitation (MR) after transcatheter mitral valve repair. Methods: 74 consecutive patients treated with MitraClip at our institution were included in the analysis. Right heart catheterization (RHC) hemodynamics were assessed to determine right atrial pressure (RAP), right ventricular diastolic pressure (RVDP), RV +dP/ dT, RV systolic pressure (RVSP), mean pulmonary artery pressure (MPAP), right ventricular failure index (RVFI, ratio of RAP to pulmonary capillary wedge pressure (PCWP)), and pulmonary vascular resistance (PVR). Transthoracic echocardiograms were reviewed to determine RA volume index (RAVI), severity of tricuspid regurgitation (TR), RV diameter, tricuspid annular plane systolic excursion (TAPSE), DTI-derived tricuspid lateral annular systolic velocity (RV S'), severity of pulmonic regurgitation (PR), RVSP, PASP, and RFVI. Cox proportional hazard models were utilized to examine the relation between variables and mortality. Results: The median STS risk was 10%. RAP >15 mmHg (HR: 4.1, 95%CI: 1.1-16), RVDP >10 mmHg (HR: 13, 95%CI: 2.5-67), MPAP >40mmHg (HR: 3.5, 95% CI: 1.03-12), RVFI (RA/PCWP) >0.63 (HR: 3.0, 95%CI: 1.04-8.5), and PVR >3 Woods units (HR: 3.5, 95% CI: 1.2-10.1) were significantly associated with increased risk of death. In contrast, none of the echocardiographic variables were predictive of death after MitraClip. Conclusions: Invasively measured reduced RV systolic function (elevated RFVI (RA/PCWP)), elevated RH filling pressures (RAP and RVDP), and pulmonary artery hypertension (elevated MPAP and PVR) may identify patients with severe MR undergoing MitraClip who are at increased risk of adverse outcomes.