Gender differences on brachial flow-mediated dilation and carotid intima-media thickness for prediction of spontaneous cardiovascular events.

BACKGROUND

Impaired brachial flow-mediated dilation (FMD) and increased carotid intima-media thickness (IMT) are associated with increased risk of cardiovascular events.

METHODS

We measured brachial FMD and a mean of 12 sites maximum carotid IMT (mmIMT) in 279 patients (mean age 62 +/- 12 y; 163 men) admitted for coronary angiography due to chest pain.

HYPOTHESIS: There are gender differences in the predictive values of FMD and IMT for cardiovascular events.

RESULTS

Univariable analysis showed that impaired FMD (p < 0.001), but not increased mmIMT (p = 0.056), significantly predicted spontaneous cardiovascular events. After adjusting for the extent of coronary artery disease (CAD) and other clinical variables, age (heart rate [HR] 1.05, 95% confidence interval [CI]: 1.01-1.09, p = 0.017) and FMD (HR 0.85, 95% CI: 0.75-0.97, p = 0.012) were independent predictors for cardiovascular events. A total of 148 (53%) patients had CAD (> or =50% diameter stenosis). Over a median follow-up of 16 mo, 36 (12.9%) patients experienced spontaneous cardiovascular events (cardiovascular death, stroke, acute myocardial infarction [MI], unstable angina pectoris, and congestive heart failure [HF]). Women were more likely than men to develop cardiovascular events in patients without significant CAD (11.9% versus 1.6%, odds ratio [OR] = 8.54, p = 0.033), but not in those patients with CAD (20.4 % versus 17.2%, OR = 1.24, p = 0.66). Moreover, women accounted for 8 (88.9%) events in non-CAD patients. Furthermore, impaired FMD predicted the occurrence of cardiovascular events in both men and women (p < 0.05).

CONCLUSION

Brachial FMD, rather than carotid IMT, was an independent predictor for cardiovascular events after adjusting for the extent of CAD. Moreover, impaired brachial endothelial function in women without significant CAD was associated with an increased risk of spontaneous cardiovascular events.