Predictive value of brachial reactive hyperemia and flow-mediated dilation in stable coronary artery disease.

BACKGROUND

The purpose of this study was to determine the predictive value of a single measurement of reactive hyperemia (RH) and brachial flow-mediated dilation (FMD) in patients with established stable coronary artery disease (CAD).

METHODS

RH and brachial artery FMD were ultrasonographically measured in 325 patients with stable CAD. Patients were followed for cerebro-cardiovascular events. The median follow-up was 3.7 years (range 0.01-5.7 years).

RESULTS

Sixty-seven patients (20.6%) had an cerebro-cardiovascular event. Patients with subsequent events had lower FMD (4.9 ± 3.3% versus 6.3 ± 3.5%, p = 0.003), higher brachial artery resting diameter (5.1 ± 0.7 mm versus 4.8 ± 0.7 mm, p = 0.002) and lower NMD (11.2 ± 5.1% versus 12.8 ± 5.4%, p = 0.02), while the mean hyperemic flow velocity and shear stress did not differ from patients without cerebro-cardiovascular events. Cox proportional hazard model adjusted for sex, age, BMI, and traditional cardiovascular risk factors revealed a hazard ratio of 0.84 for lower FMD (p = 0.01).

CONCLUSIONS

We conclude that single spot measurements of peak RH do not provide long-term prognostic information, but evaluation of conduit artery FMD predicts long-term cerebro-cardiovascular events in patients with stable CAD. The prognostic value of FMD is incremental to traditional cardiovascular risk factors and may therefore be of clinical importance.