Abstract
Background
Two randomized trials (MITRA-FR and COAPT) of transcatheter mitral valve repair (TMVR) for functional MR have shown symptomatic improvement but discordant results for heart failure hospitalizations compared to optimal medical therapy. Differences between real-world patients similar to the trial population in terms of symptomatic outcome and mortality have not been shown yet.
Purpose
Our study compared patients similar to both studies in terms of NYHA development and mortality at 1-year follow-up (FU).
Methods
In our center, 447 patients were treated with TMVR for MR grade 3 and 4 between 2012 and 2018. For the comparative analysis with MITRA-FR and COAPT, we applied filters to our database patients according to the published echocardiographic inclusion criteria and baseline data (COAPT: effective regurgitant orifice area [ERO]) 0.41±0.15cm2; left ventricular ejection fraction [LV-EF] 31.3±9.1%, left ventricular end-diastolic volume [LVEDV] 194.4±69.2ml; MITRA-FR: ERO 0.31±0.1 cm2; LV-EF 33.3±6.5, indexed LVEDV 136.2±37.4 ml).
Results
Out of our database, 91 patients were categorized as COAPT-like and 92 as MITRA-FR-like. COAPT-like patients had an ERO of 0.40±0.16cm2, LV-EF of 32.7±4.8%, LVEDV of 195±53.7ml and indexed LVEDV of 103.6±26.0ml/cm2 (Figure A). MITRA-FR-like patients had an ERO of 0.31±0.07 cm2, LV-EF of 31.7±5.0%, LVEDV of 221.7±60.8ml and indexed LVEDV of 117.9±29.1 ml/cm2. The difference of ERO and LVEDV between both groups was statistically significant. The majority of patients in both groups were in NYHA class III or IV at baseline (97% COAPT-like group, 98% MITRA-FR-like group, p=0.44).
MR reduction was equally effective in both groups, with 85 (93%) COAPT-like patients and 88 (96%) MITRA-FR-like patients having MR grade 1 or 2 at discharge. Clinical FU was available in 62 (68%) and 67 (73%) COAPT-like and MITRA-FR-like patients, respectively. The majority of patients improved symptomatically after TMVR. Before TMVR, 1 (98%) COAPT-like patient and 2 (97%) MITRA-FR-like patients were in NYHA class I or II compared to 36 (58%, p<0.01) COAPT-like patients and 38 (57%, p<0.01) MITRA-FR-like patients at FU (p=1.0 for intergroup comparison). Overall, 40 (65%) COAPT-like patients and 43 (64%) MITRA-FR-like improved at least one NYHA class (p=1.0 for intergroup comparison; Figure B). There were no differences in overall survival between groups with 68.9% of COAPT-like patients and 74.5% of MITRA-FR-like patients alive at 1-year FU (p=0.53, Figure C).
Figure 1
Conclusion
Our real-world data shows that TMVR leads to symptomatic improvement in both MITRA-FR-like and COAPT-like patients to a similar extent, despite substantial echocardiographic differences. Both patient groups have a similar survival rate.
Recurrence of Functional Versus Organic Mitral Regurgitation After Transcatheter Mitral Valve Repair: Implications from Three-Dimensional Echocardiographic Analysis of Mitral Valve Geometry and Left Ventricular Dilation for a Point of No Return
