Acute haemodynamic changes after percutaneous mitral valve repair: relation to mid-term outcomes.

Background: Percutaneous mitral valve repair (MVR) using the Evalve MitraClip has been recently introduced as a potential alternative to surgical MVR.
Objective: To assess immediate haemodynamic changes after percutaneous MVR using right heart catheterisation. Design Single-centre longitudinal cohort study.
Setting: Tertiary referral centre.
Patients: Fifty consecutive non-surgical patients (age 74±14 years, EuroSCORE 26±14) with moderate to severe (3+) and severe (4+) mitral regurgitation (MR) due to functional (56%), degenerative (30%) or mixed (14%) disease were selected.
Interventions: MitraClip implantation was performed under general anaesthesia with fluoroscopy and echocardiographic guidance. Haemodynamic variables were obtained before and after MVR using standard right heart catheterisation and oximetry.
Main Outcome Measures: Haemodynamic changes immediately before and after MVR.
Results: Acute procedural success (reduction in MR to grade 2+ or less) was achieved in 46 (92%) patients. Mitral valve clipping reduced mean pulmonary capillary wedge pressure (mPCWP) (from 17±7 to 12±5 mm Hg), PCWP v-wave (from 24±11 to 16±7 mm Hg) and mean pulmonary artery pressure (mPAP) (from 29±12 to 24±6 mm Hg), and increased the cardiac index (CI) (from 3.1±1.0 to 3.9±1.1 l/min/m(2)) (all p<0.05). On Cox univariate regression analysis, mPCWP, PCWP v-wave- and mPAP-changes were associated with death, open-heart surgery for MR and/or hospitalisation for heart failure on follow-up.
Conclusion: In a heterogeneous population with predominantly functional MR, percutaneous MVR with the Evalve MitraClip system lowers mPCWP, PCWP v-wave and mPAP by 20%, 20% and 8%, respectively, and increases the CI by 32%.