Abstract 12289: Measurement of Flow-mediated Endothelial Vasomotor Function Remains Useful for Assessment of Residual Cardiovascular Risk in Patients With CAD After Achievement of LDL-cholesterol Goals by Statin

Abstract

Residual cardiovascular risk remains after achievement of low-density lipoprotein cholesterol (LDL-C) goals with statin treatment. Although endothelial vasomotor dysfunction is a strong predictor of cardiovascular (CV) events, endothelial dysfunction is reversed by statin administration via LDL-C reduction and its pleotropic effects. However, it is unclear whether endothelial function after statin treatment may have a predictive value for future CV events. This study examined hypothesis whether endothelial function may provide a prognostic information in patients with coronary artery disease (CAD) after achievement of LDL-cholesterol goals by statin.

Methods: Flow-mediated endothelium-dependent dilation (FMD, % increase in diameter from baseline) of the brachial artery was measured in 261 consecutive CAD patients with LDL-C levels <100 mg/dL on statin treatment. All patients were prospectively followed up for a period of ≤ 36 months or until occurrence of one of following CV events: cardiac death, non fatal myocardial infarction, unstable angina requiring coronary revascularization, or stroke.

Results: During a mean follow-up of 33 months, 18 (18%) patients with impaired FMD (<5.5%, 50^th percentile of the distribution of FMD in study patients)had CV events (1 patients in cardiac death, 5 in myocardial infarction, 9 in unstable angina, 3 in stroke), while 11 (7%) patient with preserved FMD (> 5.5%) had a CV event (2 in myocardial infarction, 7 in unstable angina, 2 in stroke) (p < 0.0001). Using multivariate logistic analysis, the impaired FMD had a significant predictor value of CV events (OR; 2.8, 95%CI; 1.2 - 6.9, p < 0.01) that was independent of the Framingham risk factors. Using a c-statistic analysis, the predictive value of impaired FMD was significantly incremental over that of the conventional known risks including age, hypertension, diabetes, smoking for CV events (AUC; combination with FMD 0.64, 0.66, 0.68 and 0.70 vs. without FMD 0.52, 0.57, 0.58 and 0.60, respectively, p < 0.05).

Conclusions: Measurement of flow-mediated endothelial vasomotor function remains useful for assessment of residual cardiovascular risk in patients with CAD after achievement of LDL-cholesterol goals by statin.