• mitral regurgitation
• percutaneous mitral valve repair
• ventricular-arterial coupling

Aim of the study: The aim of the study was to analyse non-invasively global cardiovascular performance, in terms of arterial and ventricular elastances, and ventricular-arterial coupling, in patients undergoing percutaneous mitral valve repair (PMVR) with MitraClip. Moreover, we investigated these parameters correlation with patient long-term clinical outcome.
Methods and results: One hundred consecutive high surgical risk patients, who underwent PMVR with MitraClip System at three high-volume centres, were studied retrospectively. To the purpose of this study, cardiovascular performance (cardiac output (CO), cardiac index (CI), arterial (Ea) and ventricular elastances (Ees), and ventricular-arterial (VA) coupling) was assessed at baseline, discharge and 12-month follow-up. Study primary end-point was cardiovascular (CV) death. Results showed CO and CI significant increase after the procedure (p=0,005, p=0,02, respectively) with concomitant VA coupling and Ees worsening (p=0,03, p=0,004, respectively). All the parameters returned to the baseline values at 12-month follow-up. At univariate analysis, patients with CV death during the follow-up were characterized by higher EuroSCORE II values (p= 0,09), more severely enlarged left ventricle (LV end-diastolic diameter, p=0,03) and lower LV ejection fraction (p=0,07). Death was associated with impaired right ventricle systolic function (mean PVStdi, p=0,04) and higher systolic pulmonary artery pressure at baseline (p=0,05). Finally, the patient cohort, which responded to the procedure with VA coupling deterioration, was found to have better outcome (p=0,09). At multivariate Cox analysis the independent predictors of primary outcome were higher baseline LV end-diastolic diameter (OR=1,10, 95%CI=1,02-1,20, p=0,02) and absence of acute post-procedural VA coupling deterioration (OR=2,56, 95%CI=1,34-4,90, p=0,004). Patients who experienced VA coupling deterioration after MitraClip implantation demonstrated higher probability of overall survival and survival free from cardiovascular death at Kaplan-Meier analysis (Logrank test p=0,027, p=0,014, respectively).
Conclusion: In conclusion, PMVR leads to an acute modification in cardiovascular performance, mimicking surgical hemodynamic results. Post-procedural VA coupling deterioration resulted independently correlated with better clinical outcome; therefore, this parameter could be used as a marker of procedural efficacy.