Long-Term Hemodynamic Improvement after Transcatheter Mitral Valve Repair.
Background: Correction of mitral regurgitation (MR) alters the load on the left ventricle. There are few data on the long-term hemodynamic adaptations of the cardiovascular system after transcatheter mitral valve repair (TMVR). The aim of this study was to determine a comprehensive hemodynamic status using noninvasive pressure-volume analysis.
Methods: Pressure-volume parameters were calculated from echocardiography with simultaneous arm-cuff blood pressure measurements at baseline before TMVR and 12 months after TMVR. Eighty-eight consecutive patients undergoing edge-to-edge mitral clip implantation because of grade 3+ or 4+, symptomatic (79.5% in New York Heart Association functional class ≥III) MR were prospectively enrolled. The mean left ventricular (LV) ejection fraction was 42 ± 14%. Sixty-seven percent of the patients had secondary MR.
Results: Twelve months after TMVR, 17.7% of patients had died, and 19.0% were rehospitalized because of decompensated heart failure. MR grade was ≤2+ in 90% of surviving patients, and 77% were in New York Heart Association functional class ≤II. LV end-diastolic volume index decreased from 87 ± 38 to 77 ± 40 mL/m2 (P < .0001), end-systolic volume index changed from 54 ± 34 to 50 ± 36 mL/m2 (P = .018), hence total stroke volume index was reduced (from 34 ± 11 to 28 ± 7 ml/m2, P < .0001). Ejection fraction and global longitudinal peak systolic strain remained unchanged. Increased forward ejection fraction (30 ± 14% vs 41 ± 20%, P < .0001), cardiac index (from 1.7 ± 0.4 to 1.9 ± 0.5 mL/min/m2, P = .003), and peak power index (214 ± 114 vs 280 ± 149 mm Hg/sec, P = .0001) as well as similar end-systolic elastance at reduced LV volumes indicated improved LV performance. Cardiac efficiency, measured as cardiac index relative to myocardial energy, was improved (0.012 ± 0.008 vs 0.019 ± 0.010 mm Hg-1, P = .002). Logistic regression analysis revealed baseline values of total ejection fraction and diastolic pulmonary pressure gradient as predictors of clinical improvement (odds ratios, 1.076 [P = .009] and 0.812 [P = .015], respectively) after TMVR.
Conclusions: One year after TMVR, patients showed reverse remodeling and improved LV performance that was associated with improved symptom status. This hemodynamic improvement supports TMVR as long-term effective therapy for patients with symptomatic MR.