ABSTRACT
BACKGROUND: In secondary MR, data on left ventricular (LV) remodeling after MitraClip procedure are rare, even this information may impact patient selection. This study investigated changes in LV structure and function by cardiovascular magnetic resonance (CMR) following MitraClip implantation for secondary mitral regurgitation (MR) in order to assess extent and predictors of LV reverse remodeling (LVRR). METHODS AND RESULTS: Twenty-nine patients underwent CMR imaging prior to and six months after MitraClip procedure. LVRR was defined by a decrease of LV end-diastolic volume index (LVEDVi) > 15% compared to baseline. According to the definition of LVRR, 34% of patients displayed LVRR at follow-up CMR. Baseline LV stroke volume index (LVSVi), LV ejection fraction (LVEF), LV circumferential strain and MR volume at baseline were predictors of LVRR at follow-up. At second CMR, we detected an improvement in hemodynamic status as illustrated by an increase in effective LVSVi (28 ± 8 ml/m2 vs. 33 ± 8 ml/m2; p = 0.053) and cardiac index (2.0 ± 0.5 vs. 2.3 ± 0.5 l/min; p = 0.016), while LVEF and LV strain parameters did not change (p > 0.05). Improvements in effective LVSVi were associated with the decrease of MR volume (r = 0.509; p = 0.018) and MR fraction (r = 0.629; p = 0.002) by MitraClip. CONCLUSIONS: Together, MitraClip implantation is associated with LVRR in one third of patients. Baseline LV function and magnitude of MR are important predictors of LVRR. Improvement of hemodynamic status may be assessed by effective stroke volume index and correlates with the reduction of MR by MitraClip implantation, rather than an increase in LV contractility.
ABSTRACT
AIMS: To evaluate whether CMR-derived RV assessment can facilitate risk stratification among patients undergoing transcatheter mitral valve repair (TMVR). BACKGROUND: In patients undergoing TMVR, only limited data exist regarding the role of RV function. Previous studies assessed the impact of pre-procedural RV dysfunction stating that RV failure may be associated with increased cardiovascular mortality after the procedure. METHODS: Sixty-one patients underwent CMR, echocardiography and right heart catheterization prior TMVR. All-cause mortality and heart failure hospitalizations were assessed during 2-year follow-up. RESULTS: According to RV ejection fraction (RVEF) <46%, 23 patients (38%) had pre-existing RV dysfunction. By measures of RV end-diastolic volume index (RVEDVi), 16 patients (26%) revealed RV dilatation. Nine patients (15%) revealed both. RV dysfunction was associated with increased right and left ventricular volumes as well as reduced left ventricular (LV) ejection fraction (all p<0.05). During follow-up, 15 patients (25%) died and additional 14 patients (23%) were admitted to hospital due to heart failure symptoms. RV dysfunction predicted all-cause mortality even after adjustment for LV function. Similarly, RVEDVi was a predictor of all-cause mortality even after adjustment for LVEDVi. Kaplan-Meier survival analysis unraveled that, among patients presenting with CMR indicative of both, RV dysfunction and dilatation, the majority (78%) experienced an adverse event during follow-up (p<0.001). CONCLUSION: In patients undergoing TMVR, pre-existing RV dysfunction and RV dilatation are associated with reduced survival, in progressive additive fashion. The assessment of RV volumes and function by CMR may aid in risk stratification prior TMVR in these high-risk patients.
