Abstract
Background/Introduction
Recently published, diverging data of the COAPT and Mitra.fr trials yielded discussion on the impact of the magnitude of mitral valve insufficiency and of left ventricular end-diastolic volume index (LVEDVI) in patients with functional mitral regurgitation (FMR) prior to MitraClip intervention on outcome measures.
Purpose
We sought to evaluate the leverage of the effective orifice area (EROA) and LVEDVI on long-term outcome in a real-life cohort.
Methods
We stratified 394 patients (74.4±8.6 years, 60.9% male) that had been treated by MitraClip from 09/2008 to 01/2018 into four subgroups: I (FMR, EROA ≤30mm2 [n=76]), II (FMR, EROA 30–40mm2 [n=87]), III (FMR, EROA >40mm2 [n=105]) and IV (degenerative MR [DMR], n=126). Follow-up was conducted at on-site visits 6 months and annually after MC procedure up to 60 months.
Results
At baseline, patients of subgroup IV were oldest (p=0.0011), while subgroups I to III demonstrated significantly higher rates of any cardiomyopathy (I: 78.4%, II: 93.1%, III: 86.7%, IV: 47.6%, p<0.001). The left ventricular ejection fraction (LVEF) differed significantly (I: 38±13%, II: 35±14%, III: 34±14%, IV: 54±12%, p<0.001), as did EuroSCORE values (median, I: 20.4%, II: 24%, III: 23%, IV: 18.4%, p<0.001). Procedural success (placement of ≥1 Clip, residual MR ≤2+) differed significantly (I: 96.1%, II: 96.6%, III: 89.5%, IV: 87.3%, p=0.039).
Up to 60 month follow-up lasting success was noted in 87.5% (I), 81.8% (II), 87.5% (III) and 77.8% (IV) and all subgroups demonstrated a significant improvement in New York Heart Failure Association classification.
In further stratification according to LVEDVI (A: ≤96ml/m2 and B: >96ml/m2), no differences were noted in Kaplan-Meier estimates for death (A: p=0.36 and B: p=53) or in post-hoc comparison of each group (I-IV). Likewise, the combined endpoint of death and cardiac rehospitalization (A: p=0.18, B: p=0.94), MACE (A: p=0.37, B: p=0.54) and MACCE (A: p=0.16, B: p=0.49) and post-hoc comparisons of each group (I-IV) yielded no significant differences in outcome measures.
Conclusions
Despite distinct differences in baseline characteristics of each subgroup, we observed high procedural success rates, long-lasting reductions of MR and beneficial clinical outcome in all patients. In this retrospective analysis of a real-life cohort, EROA and LVEDVI did not influence long-term outcome measures. These results indicate no limitation for MitraClip treatment based on advanced stages of FMR and its underlying pathology, yet mark the necessity for further pre-procedural stratification.