Extended Cardiac Rehabilitation Does Not Improve Exercise Adherence More Than Usual Care

Abstract

PURPOSE: Exercise adherence is in general poor after cardiac rehabilitation (CR). In Norway, standard exercise-based CR typically offers 12 weeks of hospital-based supervised exercise at moderate or high intensity. The use of high-intensity interval training (HIT) in CR expands; however, it is still unclear how HIT affects exercise adherence. The purpose of this study was to assess the effect of an extended community-based or home-based CR program on long-term exercise adherence. METHODS: Between August 2014 and June 2017, 161 persons (27 women, age 62.3 (8.7) /134 men, age 60.1 (8.9)) were recruited. All had completed an HIT-based CR at St. Olav`s Hospital in Trondheim, Norway. They were randomized in a 1:1:1 ratio to an extended supervised community-based CR (ExCR) , a home-based CR (HCR) or a control group (CG). The extended CRs (ExCR and HCR) consisted of one HIT session and two additional sessions a week for eight weeks. The ExCR got a follow-up session every third month until one year after inclusion. The CG received usual care (standard advice for exercise and life style). Measurements were performed at baseline (T1), at 1 year (T2) and 2 years (T3) after inclusion. Primary outcome was peak oxygen uptake (VO2peak) at 2 years. Secondary outcome was achievement of current guidelines in regard of physical activity (PA) at moderate (MPA) and vigorous (VPA) intensity, measured with accelerometer. Data are analyzed with mixed linear model. RESULTS: Out of 161 participants, 144 (89%) completed the 2 year follow-up. VO2peak (ml/kg/min) was not significantly different between groups (p=0.777) at T1 (33.1 (7.7), 33.6 (8.5), 34.0 (7.2)), T2 (33.1 (7.9), 33.1 (8.4), 33.9 (7.4)) or T3 (30.9 (7.5), 32.2 (8.6) and 32.0 (7.3) for ExCR, HCR and CG, respectively). The decrease in VO2peak over time was significant from T2 to T3 (p=0.024). Daily average of minutes in MPA and VPA were not significantly different between groups (p=0.441 and p=0.557 respectively) at any time. There was a significant reduction from T1 to T2 in both MPA (107 (61) min to 100 (59) min, p=0.043) and VPA (14 (19) min to 11 (18) min, p=0.007). CONCLUSIONS: Extended cardiac rehabilitation did not enhance exercise adherence compared to usual care after a HIT-based CR program. Despite a decrease in VO2peak over two years, the amount of physical activity met the current guidelines.