Use of Echocardiography Studied in Patient Selection for TMVR
March 17, 2019—The American College of Cardiology (ACC) announced the presentation of a study suggesting that clinicians should utilize echocardiography when determining whether patients with heart failure and secondary mitral regurgitation are likely to benefit from valve repair. Federico M. Asch, MD, presented the findings at the ACC's 68th Annual Scientific Session, being held March 16–18 in New Orleans, Louisiana.
According to ACC, the study offers additional insights on the COAPT trial, which investigated transcatheter mitral valve repair (TMVR) with the MitraClip device (Abbott Structural Heart) in patients with secondary mitral regurgitation. The study was funded by Abbott.
In 2018, the COAPT investigators reported that patients undergoing TMVR with the MitraClip device had significantly better rates of survival at 2 years compared to those receiving standard medications alone.
According to ACC, the new study helps translate COAPT’s findings into practical guidance for clinical decision-making by detailing how echocardiography can be used to diagnose secondary mitral regurgitation. Additionally, it demonstrates the use of a multiparametric algorithm adapted from the American Society of Echocardiography and ACC guidelines to determine which patients were eligible to participate in the study and track the valve’s function over the course of 2 years.
The investigators note that there is no worldwide standard for diagnosing secondary mitral regurgitation with echocardiography; therefore, details on the study's methodology are important for informing clinical practice.
In the ACC announcement, Dr. Asch commented, “We found echocardiography is valuable for assessing patients with secondary mitral regurgitation on multiple levels. Echocardiography should be used to determine which patients are candidates for TMVR, and it should also be used after MitraClip implantation to see the results of the procedure.” Dr. Asch is Director of the Echocardiography Core Lab at MedStar Health Research Institute and Associate Professor of Medicine at Georgetown University in Washington, DC.
As summarized in the ACC announcement, COAPT enrolled 614 patients with heart failure and moderate-to-severe secondary mitral regurgitation. The patients were treated at 78 medical centers in the United States and Canada. Investigators randomized the patients to receive either the MitraClip or maximally tolerated medical therapy as recommended by clinical guidelines, which may include diuretics, ß-blockers and other medications, and cardiac resynchronization therapy.
Echocardiography was used to image patients’ hearts before enrollment and during follow-up visits at 1, 6, 12, 18, and 24 months. The investigators developed an algorithm that was used by echocardiographers to interpret the heart images, evaluate valve functioning, and determine whether patients were appropriate candidates for the MitraClip procedure. The repaired valve was effective at preventing mitral regurgitation through 2 years of follow-up.
In addition, the study focused on identifying characteristics of the heart, measurable with echocardiography, that may predict which patients would have a better or worse outcome after TMVR.
In this analysis, the investigators found that TMVR was equally beneficial across all subgroups analyzed, including size, function, or pressure of the heart chambers, leading them to conclude that all patients with similar characteristics to those in the trial should be considered for this intervention.
Dr. Asch stated, “MitraClip was shown to be beneficial in the study population in all subgroups analyzed, regardless of patients’ echocardiographic characteristics. While we learned that patients with higher pulmonary hypertension are at higher risk after they receive the MitraClip, they still do better than if they would not have had the intervention done. Doing an echocardiogram is critical in determining if a patient is a good candidate for MitraClip and in following these patients to evaluate results of the procedure in the long run.”