Article type
Year
Abstract
Objectives: (1) To update the Cochrane systematic review of the effectiveness of exercise based cardiac rehabilitation in patients with coronary heart disease (CHD) (Jolliffe et al, 2001) (2) To use meta-regression to explore the impact of patient characteristics, intervention characteristics and trial quality on treatment effect.
Methods: Searches were undertaken on a number of electronic databases (from 1st January 1999 - end date of previous review) and bibliographies of included studies. Grey literature was sought through searches of specialist rehabilitation and health technology assessment sites and contact with experts. Randomised controlled trials (RCTs) were included for review if they included patients with CHD, employed an intervention that included exercise training and assessed outcomes that included mortality, morbidity, coronary risk factors and health related quality of life (HRQoL). Two independent reviewers undertook decisions on inclusion of studies and assessment of trial quality. In addition to meta-analysis. meta regression was undertaken using pre defined patient characteristics, intervention characteristics and trial quality.
Results: An additional 15 RCTs were identified, contributing to a total of 35 RCTs - 14 trials of exercise as a single intervention (EX) and 22 trials where exercise is a component of comprehensive cardiac rehabilitation (CCR). EX and CCR trials were pooled separately. EX, but not CCR, trials reduced total mortality (RR, 0.74, 95% CI, 0.59 to 0.98; RR 0.87, 0.74 to 1.02) while both EX and CCR reduced cardiac mortality (RR 0.73, 0.56 to 0.96; OR 0.80, 0.65 to 0.99). Significant reduction was observed in total cholesterol (WMD, -0.71, -0.83 to -0.60 mmol/l), LDL cholesterol (WMD, -0.52, -0.82 to -0.22), triglycerides (WMD, -0.27, -0.45 to -0.09), systolic blood pressure (WMD, -3.5, -6.1 to -0.9) and smoking cessation (RR 0.73, 0.56 to 0.95) in CCR trials. There was no significant benefit in these risk factors with EX trials. Although not pooled, there was evidence of a consistent improvement in HRQoL across the 10 trials reporting this outcome. Meta regression revealed that the beneficial effects of exercise based cardiac rehabilitation on total mortality were independent of patient characteristics (i.e. age, sex & CHD indication), intervention characteristics (i.e. duration, 'dose' & timing post cardiac event, dose of exercise) and trial quality. .
Conclusions: This updated review confirms that exercise-based cardiac rehabilitation improves both mortality and coronary risk factors and also indicates that it may have a positive effect on patient's HRQoL. Paradoxically EX trials appear to reduce mortality but do not influence risk factors while CCR trials have the opposite effect. Meta-regression revealed no evidence that benefits are restricted to any particular subgroup of CHD patients or characteristic of exercise training such as dose or timing.
Reference
Jolliffe J, Rees K, Taylor R, Oldridge N, Thompson D, Ehrahim S. Exercise-based rehabilitation for coronary heart disease. Cochrane Database Syst Rev. 2001;(1).
Methods: Searches were undertaken on a number of electronic databases (from 1st January 1999 - end date of previous review) and bibliographies of included studies. Grey literature was sought through searches of specialist rehabilitation and health technology assessment sites and contact with experts. Randomised controlled trials (RCTs) were included for review if they included patients with CHD, employed an intervention that included exercise training and assessed outcomes that included mortality, morbidity, coronary risk factors and health related quality of life (HRQoL). Two independent reviewers undertook decisions on inclusion of studies and assessment of trial quality. In addition to meta-analysis. meta regression was undertaken using pre defined patient characteristics, intervention characteristics and trial quality.
Results: An additional 15 RCTs were identified, contributing to a total of 35 RCTs - 14 trials of exercise as a single intervention (EX) and 22 trials where exercise is a component of comprehensive cardiac rehabilitation (CCR). EX and CCR trials were pooled separately. EX, but not CCR, trials reduced total mortality (RR, 0.74, 95% CI, 0.59 to 0.98; RR 0.87, 0.74 to 1.02) while both EX and CCR reduced cardiac mortality (RR 0.73, 0.56 to 0.96; OR 0.80, 0.65 to 0.99). Significant reduction was observed in total cholesterol (WMD, -0.71, -0.83 to -0.60 mmol/l), LDL cholesterol (WMD, -0.52, -0.82 to -0.22), triglycerides (WMD, -0.27, -0.45 to -0.09), systolic blood pressure (WMD, -3.5, -6.1 to -0.9) and smoking cessation (RR 0.73, 0.56 to 0.95) in CCR trials. There was no significant benefit in these risk factors with EX trials. Although not pooled, there was evidence of a consistent improvement in HRQoL across the 10 trials reporting this outcome. Meta regression revealed that the beneficial effects of exercise based cardiac rehabilitation on total mortality were independent of patient characteristics (i.e. age, sex & CHD indication), intervention characteristics (i.e. duration, 'dose' & timing post cardiac event, dose of exercise) and trial quality. .
Conclusions: This updated review confirms that exercise-based cardiac rehabilitation improves both mortality and coronary risk factors and also indicates that it may have a positive effect on patient's HRQoL. Paradoxically EX trials appear to reduce mortality but do not influence risk factors while CCR trials have the opposite effect. Meta-regression revealed no evidence that benefits are restricted to any particular subgroup of CHD patients or characteristic of exercise training such as dose or timing.
Reference
Jolliffe J, Rees K, Taylor R, Oldridge N, Thompson D, Ehrahim S. Exercise-based rehabilitation for coronary heart disease. Cochrane Database Syst Rev. 2001;(1).