Abstract 16693: The Effect of Exercise Training on Coronary Flow Velocity Reserve in Chronic Heart Failure Patients

Introduction: Exercise training improves physical function in heart failure (HF) patients, but the exact mechanisms are not fully understood. Coronary flow velocity reserve (CFVR) is a measure of microvascular function in patients without coronary artery stenosis and in HF a low CFVR is associated with a poor prognosis. Purpose: To determine the effect of moderate continuous training (MCT) and aerobic interval training (AIT) on CFVR measured by echocardiography in HF patients Methods: The study is a substudy to the international multicenter trial SMARTEX-HF where HF patients with LVEF Results: A total of 31 patients completed 12 weeks of training with valid measurements of CFVR. Mean age was 68 (9.6) years, LVEF 30 (5) %, VO 2 peak 17.9 (5.6) ml/min/kg, CFVR 1.98 (0.8) and 20 (65%) had ischemic HF. There was no difference in change in VO 2 peak between the groups, also when combining the AIT and MCT groups into one training group (0.26 vs. 0.23, p=0.96). There was a trend towards a significant improvement in CFVR between the training group and the RRE group (0.28 vs. -0.27, p=0.06). In the subgroup of patients with ischemic HF the improvement was statistically significant (0.31 vs. -0.54, p=0.03). Conclusion: Despite only modest effect on VO 2 peak, exercise training tended to improve CFVR in HF patients and CFVR improved significantly in patients with ischemic HF. This effect should be examined in a larger study but could be part of the overall benefit of exercise training in HF. Figure legend: Box plot showing the difference in CFVR before and after 12 weeks.