Exercise-based rehabilitation for heart failure.
BACKGROUND
Previous systematic reviews and meta-analyses consistently show the positive effect of exercise-based rehabilitation for heart failure (HF) on exercise capacity; however, the direction and magnitude of effects on health-related quality of life, mortality and hospital admissions in HF remain less certain. This is an update of a Cochrane systematic review previously published in 2010.


OBJECTIVE
To determine the effectiveness of exercise-based rehabilitation on the mortality, hospitalisation admissions, morbidity and health-related quality of life for people with HF. Review inclusion criteria were extended to consider not only HF due to reduced ejection fraction (HFREF or 'systolic HF') but also HF due to preserved ejection fraction (HFPEF or 'diastolic HF').


METHODS
We updated searches from the previous Cochrane review. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (Issue1, 2013) from January 2008 to January 2013. We also searched MEDLINE (Ovid), EMBASE (Ovid), CINAHL (EBSCO) and PsycINFO (Ovid) (January 2008 to January 2013). We handsearched Web of Science, bibliographies of systematic reviews and trial registers (Controlled-trials.com and Clinicaltrials.gov).


METHODS
Randomised controlled trials of exercise-based interventions with six months' follow-up or longer compared with a no exercise control that could include usual medical care. The study population comprised adults over 18 years and were broadened to include individuals with HFPEF in addition to HFREF.


METHODS
Two review authors independently screened all identified references and rejected those that were clearly ineligible. We obtained full-text papers of potentially relevant trials. One review author independently extracted data from the included trials and assessed their risk of bias; a second review author checked data.


RESULTS
We included 33 trials with 4740 people with HF predominantly with HFREF and New York Heart Association classes II and III. This latest update identified a further 14 trials. The overall risk of bias of included trials was moderate. There was no difference in pooled mortality between exercise-based rehabilitation versus no exercise control in trials with up to one-year follow-up (25 trials, 1871 participants: risk ratio (RR) 0.93; 95% confidence interval (CI) 0.69 to 1.27, fixed-effect analysis). However, there was trend towards a reduction in mortality with exercise in trials with more than one year of follow-up (6 trials, 2845 participants: RR 0.88; 95% CI 0.75 to 1.02, fixed-effect analysis). Compared with control, exercise training reduced the rate of overall (15 trials, 1328 participants: RR 0.75; 95% CI 0.62 to 0.92, fixed-effect analysis) and HF specific hospitalisation (12 trials, 1036 participants: RR 0.61; 95% CI 0.46 to 0.80, fixed-effect analysis). Exercise also resulted in a clinically important improvement superior in the Minnesota Living with Heart Failure questionnaire (13 trials, 1270 participants: mean difference: -5.8 points; 95% CI -9.2 to -2.4, random-effects analysis) - a disease specific health-related quality of life measure. However, levels of statistical heterogeneity across studies in this outcome were substantial. Univariate meta-regression analysis showed that these benefits were independent of the participant's age, gender, degree of left ventricular dysfunction, type of cardiac rehabilitation (exercise only vs. comprehensive rehabilitation), mean dose of exercise intervention, length of follow-up, overall risk of bias and trial publication date. Within these included studies, a small body of evidence supported exercise-based rehabilitation for HFPEF (three trials, undefined participant number) and when exclusively delivered in a home-based setting (5 trials, 521 participants). One study reported an additional mean healthcare cost in the training group compared with control of USD3227/person. Two studies indicated exercise-based rehabilitation to be a potentially cost-effective use of resources in terms of gain in quality-adjusted life years (QALYs) and life-years saved.


CONCLUSIONS
This updated Cochrane review supports the conclusions of the previous version of this review that, compared with no exercise control, exercise-based rehabilitation does not increase or decrease the risk of all-cause mortality in the short term (up to 12-months' follow-up) but reduces the risk of hospital admissions and confers important improvements in health-related quality of life. This update provides further evidence that exercise training may reduce mortality in the longer term and that the benefits of exercise training on appear to be consistent across participant characteristics including age, gender and HF severity. Further randomised controlled trials are needed to confirm the small body of evidence seen in this review for the benefit of exercise in HFPEF and when exercise rehabilitation is exclusively delivered in a home-based setting.
Institute of Health Research, University of Exeter Medical School, Exeter, UK, EX2 4SG.
Rod S
RS
Taylor
Viral A
VA
Sagar
Ed J
EJ
Davies
Simon
S
Briscoe
Andrew J S
AJ
Coats
Hayes
H
Dalal
Fiona
F
Lough
Karen
K
Rees
Sally
S
Singh
D000328:Adult; D000368:Aged; D002908:Chronic Disease; D005081:Exercise Therapy / Q000401:mortality; D017079:Exercise Tolerance; D006304:Health Status; D006333:Heart Failure / Q000401:mortality / Q000534:rehabilitation*; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D008875:Middle Aged; D011788:Quality of Life; D016032:Randomized Controlled Trials as Topic; D055815:Young Adult