High-intensity interval training versus moderate-intensity continuous training on exercise capacity and quality of life in patients with coronary artery disease: A systematic review and meta-analysis

Abstract

Background Exercise is an effective strategy for reducing total and cardiovascular mortality in patients with coronary artery disease. However, it is not clear which modality is best. We performed a meta-analysis to investigate the effects of high-intensity interval versus moderate-intensity continuous training of coronary artery disease patients. Methods We searched MEDLINE, PEDro, LILACS, SciELO and the Cochrane Library (from the earliest date available to November 2016) for controlled trials that evaluated the effects of high-intensity interval versus moderate-intensity continuous training for coronary artery disease patients. Weighted mean differences and 95% confidence intervals were calculated, and heterogeneity was assessed using the I test. Results Twelve studies met the study criteria, including 609 patients. High-intensity interval training resulted in improvement in peak oxygen uptake weighted mean difference (1.3 ml/kg/min, 95% confidence interval: 0.6-1.9, n = 594) compared with moderate-intensity continuous training. No significant difference in physical, emotional, and social domain of quality of life was found for participants for participants in the high-intensity interval training group compared with the moderate-intensity continuous training group. Sub-analysis of three studies with isocaloric exercise training showed no significant difference in peak oxygen uptake weighted mean difference (0.4 ml/kg/min, 95% confidence interval: -0.1-0.9, n = 137) for participants in the high-intensity interval training group compared with moderate-intensity continuous training group. Conclusions High-intensity interval training may improve peak oxygen uptake and should be considered as a component of care of coronary artery disease patients. However, this superiority disappeared when isocaloric protocol is compared.

Physical Activity in the Prevention and Treatment of Coronary Artery Disease

“…A recent meta‐analysis of studies comparing HIT and MCT in patients with CAD confirmed the equality of these exercise modalities in achieving peak oxygen uptake, at least when exercise training was isocaloric between groups. The authors, therefore, speculated that the total energy spent on exercise training is more important to increasing peak oxygen uptake than exercise intensity 117. The number of serious adverse events with HIT was low and did not differ from MCT in patients with CAD 116, 118.…”

High intensity interval training in coronary artery disease patients, is it worth the effort?

“…However, the novelty of this study is to be found in a subgroup analysis based on whether the exercise protocols were or were not isocaloric. When Gomes-Neto et al 15 pooled the data of four trials that matched their exercise interventions for energy expenditure (EE), they found similar improvements in exercise capacity (þ0.36 ml/kg/min (-0.14 to þ0.85) P ¼ 0.16) following HIIT and MCT. These results suggest that not the intensity nor the modality but the total EE of the exercise programmes determines the improvement in exercise capacity after training.…”

“…In the present issue of this journal, a systematic review and meta-analysis was performed by GomesNeto et al 15 to provide an updated analysis of data from randomised controlled trials comparing HIIT to MCT in patients with CAD. The primary outcomes were exercise capacity and quality of life.…”

“…The challenging part of the present meta-analysis 15 is observed when the data of seven trials that applied nonisocaloric exercise interventions were pooled for analysis. In this subgroup, the increase in exercise capacity following HIIT significantly exceeded that of MCT (þ1.87 ml/kg/min (1.1 to 2.64) P < 0.001).…”

“…Nevertheless, almost all studies included in the meta-analysis of Gomes-Neto et al 15 investigated short-term effects of HIIT and MCT. Only the SAINTEX-CAD study reported 1-year follow-up results on physical activity and exercise capacity and found similar results after both training protocols.…”