Abstract 5913: Effect of Exercise training on Myocardial Perfusion, Function and Dyssynchrony, in Heart Failure Patients: A Sub-Study of the HF-ACTION Trial
Background: Although studies have indicated that exercise training can improve exercise capacity, its effect on mortality is unclear. Furthermore, it is unclear whether exercise training improves myocardial perfusion in these patients, and if so, whether it contributes to improvements in exercise capacity and or mortality. The Heart Failure and A Controlled Trial Investigating Outcomes of Exercise TraiNing (HF-ACTION) gated SPECT imaging (gSPECT) substudy was designed to test the hypotheses that the extent and severity of resting perfusion abnormalities (SRS) on gSPECT will predict outcomes, and that exercise training will provide improvement in SRS and correlate with changes in exercise capacity.
Method: HF-ACTION was a multi-center, randomized controlled trial of aerobic exercise training vs. usual care in 2331 stable patients with LVEF ≤35% and NYHA class II-IV heart failure symptoms treated with optimal therapy. Participants randomized to exercise training underwent 36 supervised aerobic training sessions at a goal frequency of 3 times/week followed by home exercise training. Subjects enrolled in the HF-ACTION sub-study underwent resting Tc 99m tetrofosmin gSPECT at baseline (n=240) and at 12 months. Images were evaluated for extent and severity of perfusion abnormalities using a 17-segment and a 5-degree gradation severity score (SRS). LV function, volumes and dyssynchrony parameters were obtained using validated available commercial software.
Results: At baseline, participants had the following characteristics: 59 years of age, 33% female, 54% ischemic etiology. Results to be presented include time-to-event analysis using baseline SRS, LV function, volumes and dyssynchrony to predict the primary end point for this ancillary study (all-cause mortality or cardiovascular hospitalization). Changes in SRS, LV function and dyssynchrony over 12 months will also be presented.
Conclusions: The gSPECT Ancillary Study of HF-ACTION presents a unique opportunity to simultaneously evaluate LV function, perfusion, volumes and dyssynchrony, their response to exercise training, and their impact on changes in exercise capacity and survival in patients with HF due to reduced left ventricular systolic function.