Abstract 13341: Enhanced External Counterpulsation Attenuates Coronary Microcirculation Dysfunction in Coronary Artery Disease With Diabetes: Primary Results of EECP-CMD Study

Abstract

Introduction: Coronary microcirculation dysfunction (CMD) is recognized as a pivotal pathophysiological change of coronary artery disease (CAD) with diabetes, however, there is little evidence for CMD medication treatment. Though enhanced external counterpulsation (EECP), a non-invasive therapy to increase shear stress of coronary flow, has been proved to release angina and restore endothelial capacities, whether EECP could attenuate CMD remains unknown. Hypothesis: EECP could attenuate CMD in patients of CAD with diabetes. Methods: This is a single center, prospective, randomized, single blind, control clinical trial (ChiCTR1800019060). Forty-eight patients [age: (57.7±8.5) yrs, 30 males] diagnosed with CAD and diabetes were enrolled during March 2019 and October 2020 in the Eighth Affiliated Hospital of Sun Yat-sen University, Shenzhen, China. The main exclusion criteria are as follows: type 1 diabetes or diabetes history≤3 years; ≥ 70 years old; acute coronary syndrome; chronic total occlusion lesions and contraindications for EECP. All accepted coronary angiography and index of microcirculation resistance (IMR) test with pressure wire, then were randomized to EECP (n=24) or control (n=24) group. All followed standard medication therapy as guidelines recommended, EECP group took 35 times of EECP (60 minutes per time, 5 times a week and 7 weeks for whole procedure) after IMR test. Another IMR test would be done at the end of 12-week follow-up, the occurrence of angina and the metabolic parameters, FMD, PWV, CPET and TTE would also be evaluated. Results: The baseline IMR displayed no significant difference in both groups [EECP: (26.56±3.70) vs. Control: (26.91±4.22), P =0.74], while IMR markedly decreased in the EECP group than control at the end of follow-up [(24.02±3.15) vs. (26.78±4.63), P =0.02]. After multivariate linear regression analysis, FMD and PWV were found to independently correlated with IMR change [FMD: (β=0.45, P =0.014); PWV: (β=-0.27, P =0.038)]. Apart from above, EECP reduced angina occurrence and improved exercise tolerance, early diastolic function of left ventricular. Conclusion: EECP attenuates CMD in CAD with diabetes through coronary microcirculation resistance decrease.