Combined assessment of flow-mediated dilation of the brachial artery and brachial-ankle pulse wave velocity improves the prediction of future coronary events in patients with chronic coronary artery disease

BACKGROUND AND PURPOSE

Measurement of either flow-mediated endothelium-dependent dilatation (FMD) of the brachial artery, brachial-ankle pulse wave velocity (baPWV), or intima-media thickness (IMT) of the carotid artery is useful for risk assessment of future cardiovascular events. This study examined whether combination of these vascular parameters may have an additive effect on the ability of traditional risk factors to predict coronary events in patients with chronic coronary artery disease (CAD).

METHODS

Patients (n=923) with stable CAD had measurements of FMD, baPWV, and maximum IMT (maxIMT), and were prospectively followed up for <8.5 years or until a coronary event - cardiac death, non-fatal myocardial infarction (MI) or unstable angina pectoris (uAP) requiring unplanned coronary revascularization.

RESULTS

During the follow-up period, 116 events occurred (29 cardiac deaths, 46 non-fatal MIs and 41 cases of uAP). A multivariate Cox proportional hazards analysis showed that FMD (HR 0.50, 95% CI 0.38-0.66) and baPWV (HR 1.52, 95% CI 1.27-1.82) but not maxIMT were significant predictors of coronary events. Based on the concordance statistics, the predictive value of traditional risk factors [area under the receiver operating characteristic curve (AUC), 0.67] was increased more by the addition of FMD and baPWV combined (AUC, 0.75) compared with the addition of either maxIMT, FMD, or baPWV alone, or the combination of maxIMT and FMD or maxIMT and baPWV (AUC, 0.67, 0.71, 0.71, 0.71 and 0.71, respectively).

CONCLUSIONS

The combined addition of FMD and baPWV to the risk assessment algorithms may be useful for risk stratification of chronic CAD patients.

Ultrasound assessment of brachial endothelial vasomotor function in addition to carotid plaque echolucency for predicting cardiovascular events in patients with coronary artery disease

BACKGROUND

Single assessment of either flow-mediated vasodilatation of the brachial artery (FMD) or carotid plaque echolucency provides prognostic information for both cerebrovascular and coronary events.

OBJECTIVES

This study tested the hypothesis that combined assessment using carotid plaque echolucency and FMD may have an additive effect when predicting cardiovascular events in patients with coronary artery disease (CAD).

METHODS

Ultrasound assessment of carotid plaque echolucency with integrated backscatter (IBS) analysis (calibrated IBS=intima-media IBS value-adventitia IBS) and FMD was performed in 547 consecutive patients with CAD. All the study patients were followed up prospectively for a period of ≤ 60 months until the occurrence of one of the following cardiovascular events: cardiac death, non-fatal myocardial infarction, unstable angina requiring coronary revascularization, or ischemic stroke.

RESULTS

During a mean follow-up period of 52 ± 10 months, 69 cardiovascular events occurred. A multivariate Cox proportional hazard model after 1000 bootstrapped resampling demonstrated that calibrated IBS and FMD were significant, independent predictors of future cardiovascular events after adjustment for known risk factors (calibrated IBS, HR 0.88, 95% CI 0.83-0.93; FMD, HR 0.76, 95% CI 0.68-0.85). The c-statistics, net reclassification improvement (NRI), and integrated discrimination improvement (IDI) analyses showed that the combination of calibrated IBS and FMD values had a greater incremental effect on the predictive value of known risk factors for cardiovascular events.

CONCLUSIONS

Combined assessment of brachial endothelial function and carotid plaque echolucency is an independent predictor of cardiovascular events and improves risk prediction when added to known risks.