[The ultrasonic measurement of the endothelial function of the brachial artery in suspected coronary heart disease].

BACKGROUND AND OBJECTIVE

A positive correlation between the presence of coronary artery disease (CAD) and peripheral endothelial dysfunction (ED) of the brachial artery has been shown in several studies. Aim of the present study was to evaluate whether the non-invasive determination of ED could also be used as a screening test in patients suspected of having CAD.

PATIENTS AND METHODS

122 patients were included. 112 had an exercise-ECG before hospital admission. Preceding coronary angiography, FMD% was measured by high-resolution ultrasound (13 Mhz). Longitudinal scans of the brachial artery were done at rest, during reactive hyperemia and after the sublingual administration of nitroglycerin.

RESULTS

In 101 of the 122 patients the presence of CAD was diagnosed by angiography, whereas 21 patients had normal coronary arteries. The extent of the vasodilation (FMD%) was found to be largely independent of the resting vessel diameters (FMD%/vessel diameter at rest: r = -0.32767 p = 0.0002). FMD% was significantly higher in patient without CAD than in the CAD group (7.01 +/- 3.5% vs. 3.73 +/- 4.11%, p < 0.001). Comparison of sensitivity and specificity to predict the presence of CAD between FMD% [sensitivity 71.3%, specificity 81%] and exercise-ECG [sensitivity 82.4%, specificity 57.1%] gave similar results. No correlation was found between the degree of the impairment of FMD% and the severely of CAD.

CONCLUSION

The determination of peripheral ED was found to be a sensitive and specific measure for predicting the presence of CAD in our cohort. Since this approach is non-invasive, non-radioactive and cost-effective it warrants further evaluation of its role as an additional screening test in patients clinically suspected of having CAD.