Background Cardiac rehabilitation (CR) is a cost-effective, evidence-based approach to managing heart disease. Rates of uptake have and continue to vary despite recommendations from the NSF for CHD and NICE. The Evaluation of the Management and Methods of Acute Coronary Events (EMMACE) 1 and 2 studies are 2 large prospective multi-centre registries of care of acute coronary syndromes (ACS) in Yorkshire undertaken in 1995 and 2003 in respectively. We studied the temporal changes in referral for and long-term survival from CR in patients who were admitted to hospital with an acute myocardial infarction (AMI).
Methods Baseline characteristics were described as numbers (%) or as means with IQRs. For Continuous variables, the Kruskal Wallis test was used for comparisons. Discrete variables were assessed by the χ2 test. Unadjusted relative risk ratios (RRR) were calculated to assess mortality after referral for CR. Kaplan–Meier (KM) curves compared unadjusted survival stratified by CR referral and EMMACE study. Log rank tests compared the survival estimates. Sex, age, STEMI, heart failure, diabetes, COPD and mini-GRACE score, revascularisation, reperfusion, ACE-inhibitors, α-blockers, statins, anti-platelet agents and admitting cardiologist were regressed (backward logistic, p<0.10 and goodness of fit with a group of 10) on CR referral and represented as 95% CI OR. A Cox proportional model (Model 1: mini-GRACE score, Model 2: sex, age, STEMI, heart failure, diabetes, COPD, EMMACE risk score, revascularisation, reperfusion, ACE-inhibitor, α-blocker, statins, anti-platelet agent, admitting cardiologist) was used to compare the temporal long-term survival estimates (all cause mortality) by CR referral.
Results 4341 had AMI. CR referral was 44% in 1995 and 59 % in 2003(p<0.001). CR referral was associated with reduced mortality in 2003 (RRR, 95%CI: 0.54; 0.50 to 0.60), but was not in 1995 (1.02; 0.96 to 1.09). Unadjusted survival for patients not referral for CR in 1995 was similar to that for patients referred for CR in 1995; (Abstract 58 figure.1). For those referred for CR, the mean mini-GRACE score for CR referrals was lower in 2003 than 1995; 0.53 and 0.72, p<0.001. After adjustment using the min-GRACE score (Model 1), the impact (HR, 95% CI) of CR referral was 0.63, 0.55 to 0.73 in 2003 and 1.07, 0.92 to 1.3 in 1995. After adjustment using Model 2, the impact (HR, 95% CI) of CR referral was 0.57, 0.48 to 0.66 in 2003 and 1.31, 1.04 to 1.60 in 1995.
Conclusion Between 1995 and 2003, referral for CR increased and became a significantly important factor contributing to reduced mortality rates post-AMI. This is despite the differences in patient and treatment factors between the 2 studies periods. Even so, rate of referral for CR remain sub-optimal.
- Cardiac rehabilitation
- acute myocardial infarction