Exercise-based cardiac rehabilitation for adults with heart failure

BACKGROUND

People with heart failure experience substantial disease burden that includes low exercise tolerance, poor health-related quality of life (HRQoL), increased risk of mortality and hospital admission, and high healthcare costs. The previous 2018 Cochrane review reported that exercise-based cardiac rehabilitation (ExCR) compared to no exercise control shows improvement in HRQoL and hospital admission amongst people with heart failure, as well as possible reduction in mortality over the longer term, and that these reductions appear to be consistent across patient and programme characteristics. Limitations noted by the authors of this previous Cochrane review include the following: (1) most trials were undertaken in patients with heart failure with reduced (< 45%) ejection fraction (HFrEF), and women, older people, and those with heart failure with preserved (≥ 45%) ejection fraction (HFpEF) were under-represented; and (2) most trials were undertaken in a hospital or centre-based setting.

OBJECTIVES

To assess the effects of ExCR on mortality, hospital admission, and health-related quality of life of adults with heart failure.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, PsycINFO and Web of Science without language restriction on 13 December 2021. We also checked the bibliographies of included studies, identified relevant systematic reviews, and two clinical trials registers.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared ExCR interventions (either exercise only or exercise as part of a comprehensive cardiac rehabilitation) with a follow-up of six months or longer versus a no-exercise control (e.g. usual medical care). The study population comprised adults (≥ 18 years) with heart failure - either HFrEF or HFpEF.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were all-cause mortality, mortality due to heart failure, all-cause hospital admissions, heart failure-related hospital admissions, and HRQoL. Secondary outcomes were costs and cost-effectiveness. We used GRADE to assess the certainty of the evidence.

MAIN RESULTS

We included 60 trials (8728 participants) with a median of six months' follow-up. For this latest update, we identified 16 new trials (2945 new participants), in addition to the previously identified 44 trials (5783 existing participants). Although the existing evidence base predominantly includes patients with HFrEF, with New York Heart Association (NYHA) classes II and III receiving centre-based ExCR programmes, a growing body of trials includes patients with HFpEF with ExCR undertaken in a home-based setting. All included trials employed a usual care comparator with a formal no-exercise intervention as well as a wide range of active comparators, such as education, psychological intervention, or medical management. The overall risk of bias in the included trials was low or unclear, and we mostly downgraded the certainty of evidence of outcomes upon GRADE assessment. There was no evidence of a difference in the short term (up to 12 months' follow-up) in the pooled risk of all-cause mortality when comparing ExCR versus usual care (risk ratio (RR) 0.93, 95% confidence interval (CI) 0.71 to 1.21; absolute effects 5.0% versus 5.8%; 34 trials, 36 comparisons, 3941 participants; low-certainty evidence). Only a few trials reported information on whether participants died due to heart failure. Participation in ExCR versus usual care likely reduced the risk of all-cause hospital admissions (RR 0.69, 95% CI 0.56 to 0.86; absolute effects 15.9% versus 23.8%; 23 trials, 24 comparisons, 2283 participants; moderate-certainty evidence) and heart failure-related hospital admissions (RR 0.82, 95% CI 0.49 to 1.35; absolute effects 5.6% versus 6.4%; 10 trials; 10 comparisons, 911 participants; moderate-certainty evidence) in the short term. Participation in ExCR likely improved short-term HRQoL as measured by the Minnesota Living with Heart Failure (MLWHF) questionnaire (lower scores indicate better HRQoL and a difference of 5 points or more indicates clinical importance; mean difference (MD) -7.39 points, 95% CI -10.30 to -4.77; 21 trials, 22 comparisons, 2699 participants; moderate-certainty evidence). When pooling HRQoL data measured by any questionnaire/scale, we found that ExCR may improve HRQoL in the short term, but the evidence is very uncertain (33 trials, 37 comparisons, 4769 participants; standardised mean difference (SMD) -0.52, 95% CI -0.70 to -0.34; very-low certainty evidence). ExCR effects appeared to be consistent across different models of ExCR delivery: centre- versus home-based, exercise dose, exercise only versus comprehensive programmes, and aerobic training alone versus aerobic plus resistance programmes.

AUTHORS' CONCLUSIONS

This updated Cochrane review provides additional randomised evidence (16 trials) to support the conclusions of the previous 2018 version of the review. Compared to no exercise control, whilst there was no evidence of a difference in all-cause mortality in people with heart failure, ExCR participation likely reduces the risk of all-cause hospital admissions and heart failure-related hospital admissions, and may result in important improvements in HRQoL. Importantly, this updated review provides additional evidence supporting the use of alternative modes of ExCR delivery, including home-based and digitally-supported programmes. Future ExCR trials need to focus on the recruitment of traditionally less represented heart failure patient groups including older patients, women, and those with HFpEF.

Social network interventions to support cardiac rehabilitation and secondary prevention in the management of people with heart disease

BACKGROUND

Globally, cardiovascular diseases (CVD, that is, coronary heart (CHD) and circulatory diseases combined) contribute to 31% of all deaths, more than any other cause. In line with guidance in the UK and globally, cardiac rehabilitation programmes are widely offered to people with heart disease, and include psychosocial, educational, health behaviour change, and risk management components. Social support and social network interventions have potential to improve outcomes of these programmes, but whether and how these interventions work is poorly understood.  OBJECTIVES: To assess the effectiveness of social network and social support interventions to support cardiac rehabilitation and secondary prevention in the management of people with heart disease. The comparator was usual care with no element of social support (i.e. secondary prevention alone or with cardiac rehabilitation).  SEARCH METHODS: We undertook a systematic search of the following databases on 9 August 2022: CENTRAL, MEDLINE, Embase, and the Web of Science. We also searched ClinicalTrials.gov and the WHO ICTRP. We reviewed the reference lists of relevant systematic reviews and included primary studies, and we contacted experts to identify additional studies.  SELECTION CRITERIA: We included randomised controlled trials (RCTs) of social network or social support interventions for people with heart disease. We included studies regardless of their duration of follow-up, and included those reported as full text, published as abstract only, and unpublished data.

DATA COLLECTION AND ANALYSIS

Using Covidence, two review authors independently screened all identified titles. We retrieved full-text study reports and publications marked 'included', and two review authors independently screened these, and conducted data extraction. Two authors independently assessed risk of bias, and assessed the certainty of the evidence using GRADE. Primary outcomes were all-cause mortality, cardiovascular-related mortality, all-cause hospital admission, cardiovascular-related hospital admission, and health-related quality of life (HRQoL) measured at > 12 months follow-up.  MAIN RESULTS: We included 54 RCTs (126 publications) reporting data for a total of 11,445 people with heart disease. The median follow-up was seven months and median sample size was 96 participants. Of included study participants, 6414 (56%) were male, and the mean age ranged from 48.6 to 76.3 years. Studies included heart failure (41%), mixed cardiac disease (31%), post-myocardial infarction (13%), post-revascularisation (7%), CHD (7%), and cardiac X syndrome (1%) patients. The median intervention duration was 12 weeks. We identified notable diversity in social network and social support interventions, across what was delivered, how, and by whom.  We assessed risk of bias (RoB) in primary outcomes at > 12 months follow-up as either 'low' (2/15 studies), 'some concerns' (11/15), or 'high' (2/15). 'Some concerns' or 'high' RoB resulted from insufficient detail on blinding of outcome assessors, data missingness, and absence of pre-agreed statistical analysis plans. In particular, HRQoL outcomes were at high RoB. Using the GRADE method, we assessed the certainty of evidence as low or very low across outcomes. Social network or social support interventions had no clear effect on all-cause mortality (risk ratio (RR) 0.75, 95% confidence interval (CI) 0.49 to 1.13, I2 = 40%) or cardiovascular-related mortality (RR 0.85, 95% CI 0.66 to 1.10, I2 = 0%) at > 12 months follow-up. The evidence suggests that social network or social support interventions for heart disease may result in little to no difference in all-cause hospital admission (RR 1.03, 95% CI 0.86 to 1.22, I2 = 0%), or cardiovascular-related hospital admission (RR 0.92, 95% CI 0.77 to 1.10, I2 = 16%), with a low level of certainty. The evidence was very uncertain regarding the impact of social network interventions on HRQoL at > 12 months follow-up (SF-36 physical component score: mean difference (MD) 31.53, 95% CI -28.65 to 91.71, I2 = 100%, 2 trials/comparisons, 166 participants; mental component score MD 30.62, 95% CI -33.88 to 95.13, I2 = 100%, 2 trials/comparisons, 166 participants).  Regarding secondary outcomes, there may be a decrease in both systolic and diastolic blood pressure with social network or social support interventions. There was no evidence of impact found on psychological well-being, smoking, cholesterol, myocardial infarction, revascularisation, return to work/education, social isolation or connectedness, patient satisfaction, or adverse events.  Results of meta-regression did not suggest that the intervention effect was related to risk of bias, intervention type, duration, setting, and delivery mode, population type, study location, participant age, or percentage of male participants.  AUTHORS' CONCLUSIONS: We found no strong evidence for the effectiveness of such interventions, although modest effects were identified in relation to blood pressure. While the data presented in this review are indicative of potential for positive effects, the review also highlights the lack of sufficient evidence to conclusively support such interventions for people with heart disease. Further high-quality, well-reported RCTs are required to fully explore the potential of social support interventions in this context. Future reporting of social network and social support interventions for people with heart disease needs to be significantly clearer, and more effectively theorised, in order to ascertain causal pathways and effect on outcomes.

Exercise-based cardiac rehabilitation for people with implantable ventricular assist devices

BACKGROUND

Heart failure is the end stage of heart disease, and the prevalence and incidence of the condition is rapidly increasing. Although heart transplantation is one type of surgical treatment for people with end-stage heart failure, donor availability is limited. Implantable ventricular assist devices (VADs) therefore offer an alternative treatment to heart transplantation. Although two studies reported the beneficial effects of exercise-based cardiac rehabilitation (CR) on functional capacity and quality of life (QOL) by performing systematic reviews and meta-analyses, both systematic reviews included studies with limited design (e.g. non-randomised, retrospective studies) or participants with implantable or extracorporeal VADs.

OBJECTIVES

To determine the benefits and harms of exercise-based CR for people with implantable VADs.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library, MEDLINE, Embase, PsycINFO, Conference Proceedings Citation Index-Science (CPCI-S) on Web of Science, CINAHL, and LILACS on 3 October 2017 with no limitations on date, language, or publication status. We also searched two clinical trials registers on 10 August 2017 and checked the reference lists of primary studies and review articles.

SELECTION CRITERIA

Randomised controlled trials (RCTs) regardless of cluster or individual randomisation, and full-text studies, those published as abstract only, and unpublished data were eligible. However, only individually RCTs and full-text publications were included.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted outcome data from the included studies. We double-checked that data were entered correctly by comparing the data presented in the systematic review with the study reports. We had no dichotomous data to analyse and used mean difference or standardised mean difference with 95% confidence intervals (CIs) for continuous data. Furthermore, we assessed the quality of evidence as it relates to those studies that contribute data to the meta-analyses for the prespecified outcomes, using GRADEpro software.

MAIN RESULTS

We included two studies with a total of 40 participants in the review. Exercise-based CR consisted of aerobic or resistance training or both three times per week for six to eight weeks. Exercise intensity was 50% of oxygen consumption (VO2) reserve, or ranged from 60% to 80% of heart rate reserve. Two serious adverse events were observed in one trial, in which participants did not complete the study due to infections. Furthermore, a total of four participants in each group required visits to the emergency department, although these participants did complete the study. Summary scores from the 36-item Short Form Health Survey (SF-36) and the Kansas City Cardiomyopathy Questionnaire (KCCQ) were measured as quality of life. One trial reported that the KCCQ summary score improved by 14.4 points in the exercise group compared with 0.5 points in the usual care group. The other trial reported that the SF-36 total score improved by 29.2 points in the exercise group compared with 16.3 points in the usual care group. A large difference in quality of life was observed between groups at the end of follow-up (standardised mean difference 0.88, 95% CI -0.12 to 1.88; 37 participants; 2 studies; very low-quality of evidence). However, there was no evidence for the effectiveness of exercise-based CR due to the young age of the participants, high risk of performance bias, very small sample size, and wide confidence intervals, which resulted in very low-quality evidence. Furthermore, we were not able to determine the effect of exercise-based CR on mortality, rehospitalisation, heart transplantation, and cost, as these outcomes were not reported.

AUTHORS' CONCLUSIONS

The evidence is currently inadequate to assess the safety and efficacy of exercise-based CR for people with implantable VADs compared with usual care. The amount of RCT evidence was very limited and of very low quality. In addition, the training duration was very short term, that is from six to eight weeks. Further high-quality and well-reported RCTs of exercise-based CR for people with implantable VADs are needed. Such trials need to collect data on events (mortality and rehospitalisation), patient-related outcomes (including quality of life), and cost-effectiveness.