Abstract 15343: Incremental Significance of Endothelial Function Assessed by Reactive Hyperemia Peripheral Arterial Tonometry to Improve Risk Stratification in High Risk Patients for Cardiovascular Events
Introduction Endothelial dysfunction is a key component of plaque vulnerability resulting in future cardiovascular events. Reactive hyperemia-peripheral arterial tonometry (RH-PAT) can noninvasively evaluate endothelial function. The morphological coronary complexity could be assessed by angiographic Synergy Between PCI With Taxus and Cardiac Surgery (SYNTAX) Score.
Hypothesis We assessed the hypothesis that the physiological assessment of endothelial function can provide the additional clinical value to SYNTAX Score and Framingham Risk Score (FRS) in predicting cardiovascular events.
Methods We enrolled 510 high risk patients for cardiovascular events from August 2006 to December 2011, and prospectively followed up until March 2012. The RH-PAT index (RHI) was measured before coronary angiography and coronary complexity was assessed by SYNTAX Score. Cardiovascular event consists of cardiovascular death, nonfatal myocardial infarction, unstable angina, ischemic stroke, coronary revascularization, re-hospitalization for heart failure, nonfatal aortic disease and peripheral arterial disease.
Results During 1339 person years of follow-up, 89 patients developed cardiovascular events. Multivariate Cox proportional hazards analysis identified B-type natriuretic peptide (BNP), SYNTAX Score and RHI as independent predictors of cardiovascular events (natural logarithm BNP: hazard ratio [HR] per 0.1: 1.02, 95% confidence interval [CI]: 1.01 - 1.04, p = 0.01, SYNTAX Score: HR per tertile increase: 2.31, 95% CI: 1.69 - 3.15, p < 0.001; RHI: HR per tertile increase: 0.55, 95% CI: 0.41 - 0.74, p < 0.001). When RHI was added to FRS, BNP and SYNTAX Score, reclassification was improved (Net reclassification index: 16.0%, p < 0.001) with substantial increase of the C-statistics (C-statistics: FRS + BNP + SYNTAX Score 0.743, FRS + BNP + SYNTAX Score + RHI 0.775), indicating the incremental significance of RHI in predicting cardiovascular outcomes.
Conclusion Advanced endothelial dysfunction significantly correlated with future cardiovascular events in high risk patients. This physiological vascular measurement improved risk discrimination when added to FRS, BNP, and anatomical plaque complexity assessed by SYNTAX Score.
- © 2012 by American Heart Association, Inc.