An analysis of the rates rehospitalisation and mortality in heart failure patients with secondary severe mitral regurgitation from the COAPT trial has found that transcatheter mitral valve repair (TMVr) with MitraClip (Abbott) reduced the total number of hospitalisations, including fatal rehospitalisation events.
This was according to Gennaro Giustino (Mount Sinai Hospital, New York, USA), who presented the findings of the analysis during a late-breaking trial session at TVT 2021 (The Structural Heart Summit, 20–22 July, Miami Beach, USA & virtual). Giustino told delegates that though the use of MitraClip compared with medical therapy alone, did reduce total hospitalisations, it not modify the association between non-fatal hospitalisation events and subsequent death.
In the opening to his presentation, Giustino remarked that the presence of secondary mitral regurgitation (MR) in patients with heart failure is associated with an increased risk of heart-failure related hospitalisation and death. “Among patients with heart failure, it has previously been shown that rehospitalisation events are associated with increased risk of morbidity mortality and healthcare costs,” he commented.
Giustino and colleagues aimed to test whether or not reducing the secondary MR with the MitraClip modulates the effect of rehospitalisation events on all-cause mortality, by characterising the impact of all-case and cause-specific hospitalisation on mortality among patients with heart failure and secondary MR treated with MitraClip plus guideline-directed medical therapy vs. guideline-directed medical therapy alone.
COAPT (Cardiovascular outcomes assessment of the MitraClip percutaneous therapy for heart failure patients with functional mitral regurgitation) is an open-label, multicentre, randomised trial evaluating the outcomes of edge-to-edge TMVr using MitraClip in symptomatic patients with heart failure and SMR. The trial found that TMVr with the MitraClip rapidly improved health status and reduced the long-term risks of death and heart failure hospitalisation in patients with heart failure and severe secondary MR who remained symptomatic despite guideline directed medical therapy.
Eligible patients had ischaemic or non-ischaemic cardiomyopathy with left ventricular ejection fraction (LVEF) of 20–50% and Left ventricular end-systolic diameter (LVESD) <7cm, moderate-to-severe (grade 3+) or severe (grade 4+ secondary MR, confirmed at an echocardiographic core laboratory before enrolment, and remained symptomatic (NYHA functional class II, III or ambulatory IV) despite maximally-tolerated guideline-directed medical therapy and cardiac resynchronisation therapy if appropriate.
Enrolled patients were randomly assigned in a 1:1 ratio to receive TMVr with the MitraClip, plus guideline-directed medical therapy or to medical therapy alone.
For the present analysis, the endpoints of interest included: all-cause hospitalisation, cardiovascular-related hospitalisation, heart failure-related hospitalisation, non-cardiovascular-related hospitalisation and all-cause mortality. Clinical follow-up was included out to two years. Giustino explained that heart failure related hospitalisation was defined as hospital admission, emergency department visit, or observation stay for >24 hours, including the presence of increased signs or symptoms of heart failure, and the administration or augmentation of IV heart failure therapy. Overnight stays at nursing home facilities, physical rehab or extended care facilities, including hospice, did not meet the protocol definition of hospitalisation.
Analyses were performed in the intention to treat population at two years post-randomisation, and the association between hospitalisation events and all-cause mortality was examined in time-varying Cox regression models including hospitalisation as a time-varying covariate. The study team evaluated the association of two-year all-cause mortality for each type of hospitalisation event, all hospitalisations and only non-fatal hospitalisations. The association between hospitalisations and mortality was evaluated separately in the MitraClip and medical therapy groups, with formal interaction testing to assess the heterogeneity of the effect of hospitalisation on mortality, according to the randomised assignment.
Detailing the results, Giustino explained that in the MitraClip group, most of the hospitalisations were non-cardiovascular related (46.37%), whereas in the guideline-directed medical therapy group they were mostly cardiovascular or heart failure related (46.03%). In terms of timing, in both groups most hospitalisations occurred between one month and one year, with most of the patients experiencing more than one hospitalisation event, Giustino added.
Outlining the findings of the time to first event analysis, Giustino revealed that MitrClip significantly reduced all-cause cardiovascular hospitalisations related to heart failure, but did not reduce cardiovascular hospitalisations not related to heart failure. There were no significant differences in terms of non-cardiovascular-related hospitalisation. Furthermore, Giustino noted that MitraClip resulted in significant reductions in all-cause fatal hospitalisation over two years, as well as heart failure-related fatal hospitalisation over the same timeframe. There were no significant differences in terms of the duration of hospitalisation, he added, a trend that was borne out across first, second and third hospitalisations in both groups.
Limitations of the study included that associations between non-fatal hospitalisations and subsequent death is subject to residual confounding, and the relatively limited time of follow-up.
Summing up the findings of the analysis, Giustino said that post-discharge hospitalisation events, particularly those that were heart failure and cardiovascular related, were associated with increased mortality. Furthermore, the use of MitraClip compared with medical therapy alone, reduced the total number of hospitalisations, including fatal rehospitalisation events, but did not modify the association between non-fatal hospitalisation events and subsequent death.