Changes in diastolic function after exercise training in patients with and without diabetes mellitus after coronary artery bypass surgery. A randomized controlled trial.

BACKGROUND

Left ventricular diastolic dysfunction and diabetes were associated with prognosis after coronary artery bypass surgery (CABG).

AIM

This study investigated whether short-term exercise improves diastolic function in patients with and without diabetes mellitus (DM) after CABG and examined the relationship of these changes to exercise capacity.

DESIGN

RCT SETTING: Outpatient.

POPULATION

Patients with left ventricular ejection fraction ≥50% after CABG were included in this study.

METHODS

Participants were randomly assigned to a control (N.=33) or exercise (N.=28) group. The exercise group participated in three-month treadmill exercise training. We evaluated all participants on diastolic function, peak oxygen uptake (VO(2peak)), and concomitant stroke volume.

RESULTS

Exercise significantly enhanced VO(2peak) to a similar extent in all patients (P<0.05). Patients with DM improved in arteriovenous oxygen difference ([a-v] O(2) diff) after training (p=0.016), whereas those without DM improved in deceleration time of early filling (p=0.031) with exercise training. The magnitude of improvement in VO(2peak) correlated with the change in (a-v) O(2) diff in patients regardless of DM (r=0.442~0.542) and with baseline (a-v) O(2) diff only in patients with DM (r=-0.480).

CONCLUSION

After CABG, all patients showed similar improvements in VO(2peak) with exercise training, mainly through increased (a-v) O(2) diff, but those without DM showed greater improvements in deceleration time.

CLINICAL REHABILITATION IMPACT

Exercise training is beneficial for improving exercise capacity associated with restorations of peripheral oxygen utilization in both patients with and without DM.