Abstract 8793: Impact of Cardiorespiratory Fitness on Characteristics of Coronary Plaque: Assessment Using Integrated Backscatter Intravascular Ultrasound and Optical Coherence Tomography

Abstract

Background: Cardiorespiratory fitness (CRF) is a predicter for the future cardiovascular disease. Rupture of vulnerable plaque that often has a large lipid core with a thin fibrous cap results in acute coronary syndrome including sudden cardiac death. We hypothesized that preserved CRF is associated with low lipid composition and thick fibrous cap thickness of coronary plaques. Methods: Both integrated backscatter intravascular ultrasound (IB-IVUS) and optical coherence tomography (OCT) were performed for 77 non-culprit coronary plaques in 77 consecutive angina pectoris patients undergoing percutaneous coronary intervention (PCI). As an indicator of CRF of patient, percentage of achieved of predicted peak oxygen consumption (%PPeak Vo 2 ) calculated based on peak Vo 2 which were directly mesured using a cardiopulmonary exercise testing post PCI was adapted. Results: Patients were classified into two groups [those with preserved CRF (%PPeak Vo 2 >82%) (group I) or others (group II)]. Coronary plaques in patients of group I had significantly smaller lipid volume, greater fibrous volume, and thicker fibrous cap thickness than those in group II (32±14% vs. 45±13%, p<0.001; 57±11% vs. 49±11%, p<0.001; and 177.7±20.9μ m vs. 143.7±36.9μ m, p<0.001). After multivariate linear regression analysis, %PPeak Vo 2 had a significantly negative correlation with lipid volume and a positive correlation with fibrous volume and fibrous cap thickness (β=-0.418, p=0.001; β=0.361, p=0.006; and β=0.339, p=0.008). Conclusions: High %PPeak Vo 2 was associated with low lipid volume, high fibrous volume and thick fibrous cap thickness in coronary plaques. Those results may explain a decreased risk of cardiovascular events in patients with preserved CRF.