Exercise-based cardiac rehabilitation for left ventricular function in patients with heart failure: A systematic review and meta-analysis

Aims: To evaluate the effect of exercise rehabilitation on the left ventricular (LV) function in patients with heart failure (HF). Methods: PubMed, Cochrane Library and Embase were searched until May 2023. Randomized controlled trials (RCTs) providing data on changes in LV function, comparing exercise to no-exercise controls with HF of any type, were included. Results: A total of 16 studies including 1443 participants were included. LV end-diastolic diameter (LVEDD) was significantly improved in the exercise group [mean differences (MD), −2.67; 95 % confidence interval (CI) (−4.88, −0.46); P=0.02], but left atrial volume index (LAVI), left ventricular end-systolic diameter (LVESD), E/e′ E/A, end-diastolic volume (EDV), end-systolic volume (ESV), left ventricular ejection fraction (LVEF) and LV mass were unaltered compared to the non-exercise group. High intensity interval training (HIIT) or with moderate exercise (MT) led to improvement in LVEDD [MD, 3.62; 95 %CI (2.55, 4.69); P<0.00001], but not LAVI, E/e′ and E/A. Sensitivity and subgroup analyses showed that the location, the type of HF and study duration may be the source of heterogeneity in LVEF. Age appears to be a source of heterogeneity in EDV and ESV. The Egger test indicated no significant publication bias. Conclusions: Exercise can partially improve LV function in patients with HF, with improvements appearing to be dependent on study quality, the type of HF, and race. However, there are some indicators that do not seem to improve or are even worse than the control group. Among all exercise modalities, HIIT shows the greatest benefit for HF patients.