High-intensity interval training improves exercise capacity in young patients with rToF

In adolescents and young adults with repaired tetralogy of Fallot (rToF), home-based high-intensity interval training (HIIT) helps increase peak oxygen consumption and maximal workload without increasing the risk of adverse events, as shown in a study.

The study included 34 patients between 12 and 30 years of age (median age 16 years) who had undergone surgical correction of ToF before age 2 years. These patients were randomly assigned to undergo a 12-week home-based HIIT programme (n=16) or receive standard of care (n=18).

The HIIT programme consisted of three 30-min sessions conducted weekly, with heart rate telemonitoring. Standard of care involved exercise as usual.

Coprimary endpoints included peak oxygen consumption (VO2) and maximal workload, analysed using linear mixed-effects (LME) models. Echocardiography, ECG, and MRI-derived measures of cardiac structure and function were also evaluated.

After the 12-week intervention, the HIIT showed a significantly greater increase in peak VO2 (mean difference, 4 mL/kg/min, 95 percent confidence interval [CI], 1.52–6.53; p=0.003) and maximal workload (mean difference, 17 W, 95 percent CI, 5–30; p=0.009) compared with those in the standard of care group.

There were no meaningful changes in cardiac volumes and ejection fraction observed after HIIT.

Notably, the improvements in VO2 in the HIIT group was observed independent of baseline fitness, BMI, and biventricular size. Lower right ventricular ejection fraction was associated with greater improvement in exercise capacity.

None of the patients experienced serious adverse events during the study.