Treatment of functional mitral regurgitation in chronic heart failure: can we get a 'proof of concept' from the MITRA-FR and COAPT trials?

Functional mitral regurgitation (FMR) is associated with poor outcomes in patients with heart failure (HF). However, it is not clear whether FMR is just a consequence of left ventricular (LV) remodelling or a factor contributing to cardiomyopathy progression. There will be more clarity about this controversy when the effects of FMR correction on outcomes will be shown. FMR correction can be performed surgically or, more often, percutaneously with the MitraClip procedure. MitraClip is the most widely used device with more than 70 000 implants performed to date. Observational studies suggest that MitraClip treatment of FMR is safe and associated with improved symptoms, quality of life and functional status in HF patients. Two recently randomized controlled clinical trials have investigated the impact of MitraClip on the outcomes of HF patients: Percutaneous Repair with the MitraClip Device for Severe Functional/Secondary Mitral Regurgitation (MITRA-FR) and Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation (COAPT). Both trials randomized patients to MitraClip plus guideline-directed medical therapy (GDMT) or GDMT alone. No reduction in the primary endpoint of all-cause mortality or HF hospitalizations was shown in MITRA-FR, whereas a significant reduction in HF hospitalizations (primary endpoint) as well as in mortality alone were shown in COAPT. The aim of this review is to summarize the pathophysiology, prevalence, prognostic role and management of FMR, focusing on the differences between MITRA-FR and COAPT and trying to provide possible explanations for the diverging results. We speculate that the two trials should be interpreted as complementary rather than opposite. Patients with severe FMR (effective regurgitant orifice area > 30 mm2 ) despite maximum tolerated GDMT (including cardiac resynchronization therapy), and without too advanced cardiomyopathy seem to be the best candidates for MitraClip treatment. MITRA-FR and COAPT provide us a long awaited 'proof of concept': FMR may be considered a leading actor in cardiomyopathy progression rather than a mere marker of severity.

Senni M ，Adamo M ，Metra M ，Alfieri O ，Vahanian A ... -  《-》

Association of Effective Regurgitation Orifice Area to Left Ventricular End-Diastolic Volume Ratio With Transcatheter Mitral Valve Repair Outcomes: A Secondary Analysis of the COAPT Trial.

Lindenfeld J ，Abraham WT ，Grayburn PA ，Kar S ，Asch FM ，Lim DS ，Nie H ，Singhal P ，Sundareswaran KS ，Weissman NJ ，Mack MJ ，Stone GW ，Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation (COAPT) Investigators ... -  《-》

Percutaneous repair of moderate-to-severe or severe functional mitral regurgitation in patients with symptomatic heart failure: Baseline characteristics of patients in the RESHAPE-HF2 trial and comparison to COAPT and MITRA-FR trials.

The RESHAPE-HF2 trial is designed to assess the efficacy and safety of the MitraClip device system for the treatment of clinically important functional mitral regurgitation (FMR) in patients with heart failure (HF). This report describes the baseline characteristics of patients enrolled in the RESHAPE-HF2 trial compared to those enrolled in the COAPT and MITRA-FR trials. The RESHAPE-HF2 study is an investigator-initiated, prospective, randomized, multicentre trial including patients with symptomatic HF, a left ventricular ejection fraction (LVEF) between 20% and 50% with moderate-to-severe or severe FMR, for whom isolated mitral valve surgery was not recommended. Patients were randomized 1:1 to a strategy of delivering or withholding MitraClip. Of 506 patients randomized, the mean age of the patients was 70 ± 10 years, and 99 of them (20%) were women. The median EuroSCORE II was 5.3 (2.8-9.0) and median plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) was 2745 (1407-5385) pg/ml. Most patients were prescribed beta-blockers (96%), diuretics (96%), angiotensin-converting enzyme inhibitors/angiotensin receptor blockers/angiotensin receptor-neprilysin inhibitors (82%) and mineralocorticoid receptor antagonists (82%). The use of sodium-glucose cotransporter 2 inhibitors was rare (7%). Cardiac resynchronization therapy (CRT) devices had been previously implanted in 29% of patients. Mean LVEF, left ventricular end-diastolic volume and effective regurgitant orifice area (EROA) were 31 ± 8%, 211 ± 76 ml and 0.25 ± 0.08 cm2, respectively, whereas 44% of patients had mitral regurgitation severity of grade 4+. Compared to patients enrolled in COAPT and MITRA-FR, those enrolled in RESHAPE-HF2 were less likely to have mitral regurgitation grade 4+ and, on average, HAD lower EROA, and plasma NT-proBNP and higher estimated glomerular filtration rate, but otherwise had similar age, comorbidities, CRT therapy and LVEF. Patients enrolled in RESHAPE-HF2 represent a third distinct population where MitraClip was tested in, that is one mainly comprising of patients with moderate-to-severe FMR instead of only severe FMR, as enrolled in the COAPT and MITRA-FR trials. The results of RESHAPE-HF2 will provide crucial insights regarding broader application of the transcatheter edge-to-edge repair procedure in clinical practice.

Anker SD ，Friede T ，von Bardeleben RS ，Butler J ，Khan MS ，Diek M ，Heinrich J ，Geyer M ，Placzek M ，Ferrari R ，Abraham WT ，Alfieri O ，Auricchio A ，Bayes-Genis A ，Cleland JGF ，Filippatos G ，Gustafsson F ，Haverkamp W ，Kelm M ，Kuck KH ，Landmesser U ，Maggioni AP ，Metra M ，Ninios V ，Petrie MC ，Rassaf T ，Ruschitzka F ，Schäfer U ，Schulze PC ，Spargias K ，Vahanian A ，Zamorano JL ，Zeiher A ，Karakas M ，Koehler F ，Lainscak M ，Öner A ，Mezilis N ，Theofilogiannakos EK ，Ninios I ，Chrissoheris M ，Kourkoveli P ，Papadopoulos K ，Smolka G ，Wojakowski W ，Reczuch K ，Pinto FJ ，Zmudka K ，Kalarus Z ，Adamo M ，Santiago-Vacas E ，Ruf TF ，Gross M ，Tongers J ，Hasenfuß G ，Schillinger W ，Ponikowski P ... -  《-》

Transcatheter Edge-to-Edge Repair in 5,000 Patients With Secondary Mitral Regurgitation: COAPT Post-Approval Study.

Real-world applicability of the COAPT (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation) randomized controlled trial (RCT) has been debated because of careful patient selection and the contrasting results of the MITRA-FR (Multicentre Study of Percutaneous Mitral Valve Repair MitraClip Device in Patients with Severe Secondary Mitral Regurgitation) RCT. The COAPT-PAS (COAPT Post-Approval Study) was initiated to assess the safety and effectiveness of the MitraClip in patients with secondary mitral regurgitation (SMR). COAPT-PAS is a prospective, single-arm, observational study of 5,000 consecutive patients with SMR treated with the MitraClip at 406 U.S. centers participating in the TVT (Transcatheter Valve Therapy) registry from 2019 to 2020. The 1-year outcomes from the COAPT-PAS full cohort and the COAPT-like and MITRA-FR-like subgroups who met RCT inclusion/exclusion criteria are reported. Patients in the COAPT-PAS had more comorbidities, more severe HF and functional limitations, and less guideline-directed medical therapy than those in the COAPT or MITRA-FR RCTs. Patients in the COAPT-PAS full cohort and the COAPT-like (n = 991) and MITRA-FR-like (n = 917) subgroups achieved a 97.7% MitraClip implant rate, a similar and durable reduction of mitral regurgitation to ≤2+ at 1 year (90.7%, 89.7%, and 86.6%, respectively), a large improvement in quality of life at 1 year (Kansas City Cardiomyopathy Questionnaire +29 COAPT-PAS, +27 COAPT-like, and +33 MITRA-FR-like), faster procedure times, similar or lower clinical event rates compared with the RCTs' MitraClip arms, and lower clinical event rates than the RCTs' guideline-directed medical therapy only arms. One-year heart failure hospitalizations was 18.9% in COAPT-PAS, 19.7% in COAPT-like compared with 24.9% in COAPT-RCT, and 28.7% in COAPT-PAS-MITRA-FR-like compared with 47.4% in MITRA-FR-RCT. This large, contemporary, real-world study reinforces the safety and effectiveness of the MitraClip System in patients with SMR, including those who met the COAPT or MITRA-FR RCT inclusion/exclusion criteria and patients excluded from the RCTs.

Goel K ，Lindenfeld J ，Makkar R ，Naik H ，Atmakuri S ，Mahoney P ，Morse MA ，Thourani VH ，Yadav P ，Batchelor W ，Rogers J ，Whisenant B ，Rinaldi M ，Hermiller J ，Lindman BR ，Barker CM ... -  《-》

One more option in heart failure: correction of mitral regurgitation with MitraClip(®).

Bini T ，Agostini C ，Stolcova M ，Meucci F ，Di Mario C ... -  《-》