Peak oxygen uptake after cardiac rehabilitation: a randomized controlled trial of a 12-month maintenance program versus usual care.

Exercise capacity is a strong predictor of survival in patients with coronary artery disease (CAD). Exercise capacity improves after cardiac rehabilitation exercise training, but previous studies have demonstrated a decline in peak oxygen uptake after ending a formal rehabilitation program. There is a lack of knowledge on how long-term exercise adherence can be achieved in CAD patients. We therefore assessed if a 12-month maintenance program following cardiac rehabilitation would lead to increased adherence to exercise and increased exercise capacity compared to usual care.Two-centre, open, parallel randomized controlled trial with 12 months follow-up comparing usual care to a maintenance program. The maintenance program consisted of one monthly supervised high intensity interval training session, a written exercise program and exercise diary, and a maximum exercise test every third month during follow-up. Forty-nine patients (15 women) on optimal medical treatment were included following discharge from cardiac rehabilitation. The primary endpoint was change in peak oxygen uptake at follow-up; secondary endpoints were physical activity level, quality of life and blood markers of cardiovascular risk.There was no change in peak oxygen uptake from baseline to follow-up in either group (intervention group 27.9 (±4.7) to 28.8 (±5.6) mL·kg (-1) min (-1), control group 32.0 (±6.2) to 32.8 (±5.8) mL·kg (-1) min (-1), with no between-group difference, p = 0.22). Quality of life and blood biomarkers remained essentially unchanged, and both self-reported and measured physical activity levels were similar between groups after 12 months.A maintenance exercise program for 12 months did not improve adherence to exercise or peak oxygen uptake in CAD patients after discharge from cardiac rehabilitation compared to usual care. This suggests that infrequent supervised high intensity interval training sessions are inadequate to improve peak oxygen uptake in this patient group.ClinicalTrials.gov NCT01246570

Patient characteristics and medication use at baseline.

<p>Data are given as numbers with percentages in parenthesis when not otherwise specified. PCI; percutaneous coronary intervention, CABG; coronary artery bypass grafting, PAD; peripheral artery disease, ACE; angiotensin converting enzyme inhibitors, ARA; angiotensin II receptor antagonists. * Between group difference at baseline (p = 0.02).</p><p>Patient characteristics and medication use at baseline.</p

Self-reported physical activity.

<p>Data are given as numbers with percentages in parenthesis.</p><p>* Valid questionnaires for 19 patients at baseline and 21 patients at follow-up in the intervention group, and 22 patients at baseline and follow-up in the control group.</p><p>Self-reported physical activity.</p

Outcome measures at baseline and after 12 months follow-up.

<p>VO_2peak; peak oxygen uptake, RER_peak; respiratory exchange ratio at peak oxygen uptake, HR_peak; peak heart rate, HRR, 1 min; heart rate recovery the first minute after ending an exercise test, HR; resting heart rate, SBP; systolic blood pressure, DBP; diastolic blood pressure, BMI; body mass index, hsCRP; high-sensitive C-reactive protein, LDLc; low-density lipoprotein cholesterol, HDLc; high-density lipoprotein cholesterol, TG; triglycerides, HbA1c; glycosylated haemoglobin.</p><p>* indicates within-group changes from baseline to 12 months,</p>‡<p> indicates between groups changes in mean difference.</p><p>Outcome measures at baseline and after 12 months follow-up.</p

Flow chart of participants throughout the study.

<p>Flow chart of participants throughout the study.</p