Insights From the MATTERHORN: Transcatheter Repair vs. Mitral Valve Surgery For Secondary Mitral Regurgitation
Quick Takes
- Based on the results from the MATTERHORN (A Multicenter, Randomized, Controlled Study to Assess Mitral Valve Reconstruction for Advanced Insufficiency of Functional or Ischemic Origin), transcatheter edge-to-edge repair (TEER) is noninferior to mitral valve (MV) surgery in patients with heart failure and secondary mitral regurgitation at 1 year.
- Patient selection is key for success of any surgical or percutaneous MV interventions.
- Generalization of these results to the current heart failure with reduced ejection fraction (HFrEF) population is challenging because the MATTERHORN encompassed four generations of TEER devices, the study population was not enriched with a low ejection fraction population, and there have been major innovations in guideline-directed medical therapy for HFrEF since the study’s inception.
Transcatheter edge-to-edge repair (TEER) and mitral valve (MV) surgery (both replacement and repair) are two approaches for managing patients with heart failure (HF) and secondary mitral regurgitation (MR). The MATTERHORN (A Multicenter, Randomized, Controlled Study to Assess Mitral Valve Reconstruction for Advanced Insufficiency of Functional or Ischemic Origin) was a multicenter, prospective, randomized, parallel-controlled study from Germany whose results were recently published in the New England Journal of Medicine.1 The study investigators sought to determine whether TEER with the MitraClip™ device (Abbott Laboratories, Abbott Park, Illinois) is noninferior to MV surgery in patients with HF and clinically significant secondary MR who are deemed to be at high surgical risk. Baseline characteristics of this population were fairly balanced in the two groups. The mean age was 70.5 years, with 39.9% women, median Society of Thoracic Surgeons Predicted Risk of Mortality (STS-PROM) score 2%, mean left ventricular ejection fraction (LVEF) 43%, and median effective regurgitant orifice area 0.22 cm2. TEER was found to be noninferior in the primary composite endpoint, which included all deaths, HF hospitalizations, stroke, or assist device within 1 year, thereby supporting its use as a first-line treatment for patients with HF and secondary MR. TEER had a significantly lower rate of major adverse events (14.9%) than did MV surgery (54.8%), suggesting it to be a safer alternative for a select group of patients.
A retrospective cohort study using the Nationwide Readmissions Database (NRD) compared patients with primary and secondary MR who underwent TEER versus surgical MV repair. The study findings demonstrated that TEER had better short-term outcomes but significantly higher medium-term major adverse cardiovascular events than did MV surgery in both cohorts.2 In contrast, the MATTERHORN prospectively included patients with secondary MR only. However, the prespecified number of 210 patients was met over a prolonged duration from 2015 to 2022. During this time, the MitraClip had four generational changes and all the generations were used in the study. Additionally, guideline-directed medical therapy (GDMT) for HF has considerably improved and these improvements were implemented over the course of the study. When the study was initiated, secondary MR guidelines did not include TEER. Since then, study data have shown that, when added to GDMT for severe functional MR with low LVEF, TEER leads to lower all-cause mortality and HF hospitalization rates through 5 years of follow-up compared with GDMT alone.3 Since study initiation, US guidelines have given TEER a Class 2a recommendation if the anatomy is favorable and surgery a Class 2b recommendation,4 whereas European guidelines have given valve surgery a class I recommendation for secondary MR and TEER a class IIa recommendation if not appropriate for surgery.5
Although the MATTERHORN provided valuable data, the study's population may not fully represent all patients with HF and MR, potentially limiting the applicability of its findings. A 1-year follow-up may not capture long-term outcomes, such as late reintervention rates or persistent symptoms in patients with secondary MR. Almost 50% patients had LVEF >40%. The study data did not capture all the follow-up quality-of-life measures endpoints, which are crucial in evaluating the overall benefit of these interventions for patients with HF. Nonetheless, this study's results contribute significantly to the ongoing discussion regarding treatment options for HF with secondary MR. The results support TEER as a safe and effective alternative to surgical options, aligning with a broader trend in cardiology toward minimally invasive interventions. It remains difficult to gauge how the results of the MATTERHORN will impact clinical practice in the current era of isolated MV surgery for secondary MR becoming exceedingly rare and TEER undergoing rapid growth, with an exponential rise in the ratio of TEER to MV surgery this past decade.6
The management of secondary MR should continue to place the utmost importance of maximizing GDMT and TEER as an option for patients whose symptoms persist despite GDMT. Ultimately, the decision between TEER or MV surgery should involve multidisciplinary team discussions and should be based on the patient's characteristics, including age, comorbidities, LVEF, and the degree of MV disease.
References
- Baldus S, Doenst T, Pfister R, et al.; MATTERHORN Investigators. Transcatheter repair versus mitral-valve surgery for secondary mitral regurgitation. N Engl J Med 2024;Aug 31:[ePub ahead of print].
- Majumdar M, Patel KN, Doshi R, et al. Transcatheter versus surgical mitral valve repair in patients with mitral regurgitation. Eur J Cardiothorac Surg 2024;65:[ePub ahead of print].
- Stone GW, Abraham WT, Lindenfeld J, et al.; COAPT Investigators. Five-year follow-up after transcatheter repair of secondary mitral regurgitation. N Engl J Med 2023;388:2037-48.
- Otto CM, Nishimura RA, Bonow RO, et al.; Writing Committee Members. 2020 ACC/AHA guideline for the management of patients with valvular heart disease: a report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines. J Am Coll Cardiol 2021;77:e25-e197.
- Vahanian A, Beyersdorf F, Praz F, et al.; ESC/EACTS Scientific Document Group. 2021 ESC/EACTS guidelines for the management of valvular heart disease. Eur Heart J 2022;43:561-632.
- Young MN, Kearing S, Albaghdadi MA, Latib A, Iribarne A. Trends in transcatheter vs surgical mitral valve repair among Medicare beneficiaries, 2012 to 2019. JAMA Cardiol 2022;7:770-2.
Clinical Topics: Heart Failure and Cardiomyopathies, Valvular Heart Disease, Acute Heart Failure, Mitral Regurgitation, Invasive Cardiovascular Angiography and Intervention
Keywords: ESC Congress, ESC24, Mitral Valve Insufficiency, Mitral Valve, Heart Failure