Frail Patients Benefit From MitraClip, With Gains in Function and Quality of Life

Frail patients who undergo transcatheter mitral valve repair have a higher risk of death at 6 weeks compared with non-frail patients, but if they survive, they experience similar relative improvements in functional capacity and quality of life as non-frail patients, a new study shows. 

At 6 weeks, frail and non-frail patients both had improvements in NYHA class, 6-minute walk distances, Minnesota Living with Heart Failure Questionnaire (MLWHFQ) scores, and mental and physical quality of life scores. The magnitude of improvement did not differ between frail and non-frail patients, but frail patients made larger gains in the MLWHFQ scores.

“You can treat even frail patients with a high degree of safety,” senior investigator Roman Pfister, MD (University of Cologne, Germany), told TCTMD. “From the patients’ perspective, it’s very important to say that even frail patients show substantial improvements in functional capacity and quality of life. The absolute values were still lower in frail patients after the procedure, but the relative benefit was at least of similar magnitude as the non-frail patients.”

Published September 13, 2017, in JACC: Cardiovascular Interventions, the new study included 213 patients admitted for transcatheter mitral valve repair with MitraClip (Abbott Vascular) at a single center between 2014 and 2016. One-third of patients had primary/degenerative, and 57% had secondary/functional mitral regurgitation (the remainder had combined degenerative and functional disease). Pfister said that given the age of the patients (median 78 years) and the number of their comorbidities, the prevalence of frailty would be expected to be quite high. Unknown, however, was how well these patients would fare in terms of procedural and short-term outcomes when compared with more robust patients.

You can treat even frail patients with a high degree of safety. Roman Pfister

“Frailty, as by its definition, means that patients are susceptible to any kind of stressor,” said Pfister. “They don’t have a high level of resistance. Even minor procedures can lead to a severe deterioration of frail patients. One might expect that patients undergoing the MitraClip procedure could have worsened functional capacity, at least in the first days and weeks after the procedure.”

Frailty was assessed based on Fried criteria, which include unintentional weight loss, weakness, self-reported exhaustion, slowness in walking, and low physical activity caused by heart failure symptoms. In total, 97 patients were classified as frail. These patients did not differ in terms of sex, mitral regurgitation pathology, and surgical risk scores but were older, more likely to have previous cardiac surgery, and worse renal function compared with non-frail patients.

Technical success of repair, defined as a reduction in mitral regurgitation to grade 2 or lower, was similar in frail and non-frail patients. Overall, 8.3% of frail patients had died by 6 weeks compared with 1.7% of non-frail patients (P = 0.03). Pro-NT-brain natriuretic peptide (BNP) levels decreased in both frail and non-frail patients, and to a larger extent in frail patients, although the between-group difference was not statistically significant. As noted, functional parameters and quality of life were significantly improved with MitraClip in the frail and non-frail patients.

After a median follow-up of 429 days, 17.8% of patients had died and 16.9% were hospitalized for heart failure. Frail patients had a higher mortality and hospitalization rate than non-frail patients, with the risk of death threefold higher in frail patients and hospitalization twofold higher. Frailty remained significantly associated with the risk of death and hospitalization after adjusting for baseline surgical risk scores. 

Mortality Curves Separate Early

To TCTMD, Pfister said transcatheter mitral valve repair with MitraClip is not expected to reduce mortality or hospital readmissions. Instead, the primary aim of treatment is improvement in symptoms and function. He noted that device success and complications were similar in frail and non-frail patients, which likely reflects the “low demand” on the patient compared with other procedures, such as TAVR. 

He added that the survival curves separated early—at 4 to 6 weeks—and continued to diverge over the follow-up period. “This also confirms that frailty is a very potent predictor of mortality no matter what patients you look at,” Pfister commented.

Tamim Nazif, MD (Columbia University Medical Center, New York, NY), who was not involved in the study, said one message from the analysis is that frailty has a similar impact in patients with severe symptomatic mitral regurgitation as it does in patients with aortic stenosis referred for TAVR.

“The device success and early mortality were similar in the frail and non-frail patients [with MitraClip],” he told TCTMD. “The frail patients had at least equivalent, if not better, functional improvements at the early time points. So I think that shows there’s benefit to the procedure in these frail patients.”

In the long term, though, the frail patients do worse than their non-frail counterparts, which is also observed in TAVR. “Patients can undergo the procedure safely,” said Nazif. “If they do, they have substantial benefits in function and quality of life, but in the long term they are still a very high-risk patient population. They have higher mortality and higher rehospitalization in the long term. . . . It speaks to the fact that they are a sicker patient population.”    

Improved QoL an Acceptable Outcome

Suzanne Arnold, MD (Saint Luke’s Mid America Heart Institute, Kansas City, MO), who wrote an editorial accompanying the study, said elderly patients considered for MitraClip are likely to be frail given that they are referred for the procedure if they are considered too risk for surgery. Patients who are not frail, she added, may be better served by traditional cardiac surgery.

To TCTMD, Arnold said the study results are reassuring.

“Frail patients, who we know will have higher long-term mortality, still can get through the procedure fairly well and have a good short-term quality-of-life benefit,” she said. “I think for a procedure that is fairly nonintrusive with a low complication rate, low length of stay, and not excessive in costs, a reasonable survival and improvement in quality of life is an acceptable outcome.”

Despite the minimal perioperative risk, MitraClip outcomes are still suboptimal compared with surgery, and the procedure should still be limited to patients who are unable to undergo the more definitive treatment of their mitral regurgitation, according to Arnold.

Clinical guidelines recommend a frailty assessment for patients with valvular heart disease considered for surgery, and while such an assessment is helpful in directing patients toward transcatheter mitral valve repair, it doesn’t necessarily add much information if the patient is already referred for the less invasive approach.

“The assessment of frailty does not alter the decision as to whether or not to [undergo transcatheter mitral valve repair], as the frail patients still had a benefit,” said Arnold. “Perhaps it could be used here to institute measures that might improve outcomes, but at this point, there haven’t been a lot of interventions that have been proven beneficial. As such, it is hard to argue for the assessment of frailty, which is fairly cumbersome, in patients in whom the decision for transcatheter mitral valve repair has already been made.”

Nazif said the impact of frailty is more established in aortic stenosis, with the development of TAVR leading to studies evaluating the effect of frailty on clinical outcomes.

“We know frailty is a syndrome that impacts not just patients with aortic stenosis, but other domains of cardiology,” Nazif told TCTMD. “Anywhere you have a population of elderly patients with multiple medical comorbidities, there is likely to be a burden of frailty and that’s what we’re seeing here. In TAVR, especially the early studies, we began to more intensively study elderly patients with comorbidities than had previously been done. We’re seeing the same thing now in these mitral patients.”