Training-induced change of diastolic function in heart failure with preserved ejection fraction

Gevaert AB, Winzer EB, Mueller S, De Schutter S, Beckers PJ, Hommel J, Linke A, Wisløff U, Adams V, Pieske B, Halle M, Van Craenenbroeck EM, Van De Heyning CM

Question

In patients with HFpEF from the OptimEx-Clin randomized trial, does exercise training improve systolic or diastolic function measured during exercise echocardiography, and do those cardiac changes explain changes in VO2peak?

Summary

This prespecified OptimEx-Clin substudy tested whether exercise training improves cardiac function during exercise in older adults with heart failure with preserved ejection fraction. Participants were randomized to guideline advice, moderate continuous training, or HIIT; the two exercise groups were pooled for this echocardiography substudy. Exercise training improved VO2peak after 3 months, but only small changes in exercise E/e' were seen and these did not explain the fitness improvement.

Methodology

61 older adults with HFpEF in an exercise echocardiography substudy of OptimEx-Clin; 21 guideline control and 40 pooled exercise training participants.
61 participants.
Aerobic interval training and moderate continuous training.
Work intervals: HIIT: 4 min at 80%-90% heart-rate reserve.
Recovery: HIIT: 3 min exercise at 35%-50% heart-rate reserve between intervals.
Intensity: HIIT intervals 80%-90% heart-rate reserve; lower-intensity segments and MCT 35%-50% heart-rate reserve.
HIIT 38 min; MCT 40 min.
HIIT 3 times/week; MCT 5 times/week.
3 months.
Prespecified substudy of a multicentre randomized controlled trial, pooling HIIT and moderate continuous training groups against guideline control for exercise echocardiography analyses.
VO2peak, Exercise E/e' ratio, Peak workload, and RV-vascular coupling were tracked.

Outcomes

VO2peak

Exercise training increased VO2peak by +2.7 mL/kg/min compared with +0.2 mL/kg/min in guideline controls.

P-interaction = 0.006; table values training 16.8 +/- 5.7 to 19.5 +/- 5.6 mL/kg/min, control 17.3 +/- 4.7 to 17.5 +/- 5.5.

Improved

Percent predicted VO2peak

Percent predicted VO2peak increased more in training than control.

+7% versus +1%; P-interaction = 0.021.

Improved

Peak workload

Peak workload increased in the training group and decreased slightly in controls.

+11 versus -2 W; P-interaction < 0.001.

Improved

Exercise E/e' ratio

Training showed a smaller maximal exercise E/e' value at 3 months than control, but the E/e' change did not explain VO2peak improvement.

Maximal E/e' control 21.70 +/- 7.47 to 22.88 +/- 9.23, training 18.26 +/- 5.01 to 17.23 +/- 4.14; P-interaction = 0.044.

Mixed

Other resting or exercise echocardiography measurements

No significant between-group differences were found for LVEF, MAPSE, S', A', PAPs, TAPSE, or RV-vascular coupling.

Reported as P > 0.05 for those parameters.

No clear change

Insights

In supervised HFpEF rehabilitation, improved VO2peak may occur without major measured improvements in cardiac echocardiographic function.
HIIT evidence from this paper should be framed as clinical and indirect because HIIT and MCT were pooled.
Heart-rate-reserve interval prescriptions require monitoring and are not directly equivalent to app-only perceived-intensity workouts.

Limitations

Substudy sample size was not powered for all echocardiographic mechanisms.
HIIT and MCT groups were pooled.
Advanced HFpEF phenotype limits generalizability to earlier HFpEF.
Image quality and body habitus limited some echocardiographic measurements.
No stroke volume, cardiac output, or simultaneous VO2 plus echocardiographic measurement.
Not directly translatable to unsupervised consumer HIIT.

Safety

This substudy article does not report specific exercise-training adverse-event counts.
Exercise testing used clinical monitoring, including continuous ECG and heart rate plus blood pressure at each increment.
Training was delivered in cardiac rehabilitation and telemonitoring contexts.