Effect of maximal-intensity and high-intensity interval training on exercise capacity and quality of life in patients with acute myocardial infarction: a randomized controlled trial.

BACKGROUND

An increase in V̇O2max is important for acute myocardial infarction morbidity, and recurrence rate and intensity have been suggested as important factors in improving V̇O2max.

AIM

The aim of this study was to compare the effects of maximal-intensity interval training (MIIT) and high-intensity interval training (HIIT) on exercise capacity and health-related Quality of Life (HRQoL) in patients with acute myocardial infarction (MI) at low and moderate cardiac risk in cardiac rehabilitation (CR). This study secondarily aimed to compare the effects of hospital-based phase II CR and usual care.

DESIGN

This study is a randomized controlled trial.

SETTING

Outpatient Rehabilitation Setting.

POPULATION

Fifty-nine patients with acute MI were randomly assigned to the MIIT (N.=30) or HIIT (N.=29) group, and 32 to the usual care group.

METHODS

Twice a week, an intervention was conducted for nine weeks in all groups. The maximum oxygen intake (V̇O2max) and MacNew Heart Disease HRQoL were evaluated before and after intervention.

RESULTS

A significant interaction was observed between time and group for V̇O2max (P<0.001). The MIIT group showed greater improvement than those exhibited by the HIIT and usual care groups (P<0.05). Similarly, a significant time and group interaction was observed on the MacNew Global, Physical, and Emotional scales (P<0.05), but not on the social scale (P>0.05).

CONCLUSIONS

Compared to HIIT and usual care, MIIT significantly increased the V̇O2max and was as safe as HIIT in patients with acute MI with low and moderate cardiac risk in CR. Additionally, MIIT and HIIT were superior to usual care in terms of improving the HRQoL.

CLINICAL REHABILITATION IMPACT

Our results suggest that increased intensity in phase II CR could result in better outcomes in terms of V̇O2max increment in patients with acute MI and low and moderate cardiac risk in CR.