Clinical outcomes after cardiac rehabilitation in elderly patients with and without diabetes mellitus: The EU-CaRE multicenter cohort study

BACKGROUND: The prevalence of patients with concomitant cardiovascular disease and diabetes mellitus (DM) is increasing rapidly. We aimed to compare the effectiveness of current cardiac rehabilitation (CR) programs across seven European countries between elderly cardiac patients with and without DM. METHODS: 1633 acute and chronic coronary artery disease (CAD) patients and patients after valve intervention with an age 65 or above who participated in comprehensive CR (3 weeks to 3 months, depending on centre) were included. Peak oxygen uptake (VO(2) peak), body mass index, resting systolic blood pressure, low-density lipoprotein-cholesterol (LDL-C), and glycated haemoglobin (HbA1c) were assessed before start of CR, at termination of CR (variable time point), and 12 months after start of CR, with no intervention after CR. Baseline values and changes from baseline to 12-month follow-up were compared between patients with and without DM using mixed models, and mortality and hospitalisation rates using logistic regression. RESULTS: 430 (26.3%) patients had DM. Patients with DM had more body fat, lower educational level, more comorbidities, cardiovascular risk factors, and more advanced CAD. Both groups increased their VO(2) peak over the study period but with a significantly lower improvement from baseline to follow-up in patients with DM. In the DM group, change in HbA1c was associated with weight change but not with change in absolute VO(2) peak. 12-month cardiac mortality was higher in patients with DM. CONCLUSIONS: While immediate improvements in VO(2) peak after CR in elderly patients with and without DM were similar, 12-month maintenance of this improvement was inferior in patients with DM, possibly related to disease progression. Glycemic control was less favourable in diabetic patients needing insulin in the short- and long-term. Since glycemic control was only related to weight loss but not to increase in exercise capacity, this highlights the importance of weight loss in obese DM patients during CR. Trial registration NTR5306 at trialregister.nl; trial registered 07/16/2015; https://www.trialregister.nl/trial/5166