Endothelial dysfunction, intima-media thickness and coronary reserve in relation to risk factors and Framingham score in patients without clinical atherosclerosis.

BACKGROUND: Endothelial dysfunction, decreased coronary flow reserve (CFR) and increased intima-media thickness (IMT) are related to atherosclerosis and can be assessed non-invasively by echography.
OBJECTIVES: In order to describe the relationship between these parameters and with cardiovascular risk, this study investigated them simultaneously in patients without clinical atherosclerosis.
METHODS: A total of 106 subjects were studied, 91 with and 15 without cardiovascular risk factors. Cardiovascular disease was excluded in all cases. Doppler ultrasound was used to analyse endothelium-dependent vascular dilation in the brachial artery, IMT in the common carotid artery and CFR in the left anterior artery.
RESULTS: Patients with cardiovascular risk factors had impaired flow-mediated dilation (FMD; 3.7 +/- 3.2 versus 11.6 +/- 4.4%, P = 0.000); greater IMT (0.89 +/- 0.3 versus 0.56 +/- 0.14 mm, P = 0.000) and lower CFR (2.7 +/- 0.9 versus 4 +/- 1.2, P = 0.000). Correlation was found between IMT and FMD r = -0.240, (P = 0.013), IMT and CFR, r = -0.384 (P = 0.000), and between FMD and CFR of r = 0.289 (P = 0.007). All patients with IMT greater than 1 mm showed depressed FMD, most of them with low values of CFR, but patients with reduced FMD or CFR did not necessarily show increased IMT. There was a significant correlation between the three parameters and the Framingham risk score. Multiple linear regression analysis showed that IMT was the only factor related to the Framingham score.
CONCLUSION: In patients without clinical atherosclerotic disease, cardiovascular risk factors are associated with impaired FMD, CFR and increased IMT. Even though a correlation between these changes was found, they showed different dependence on cardiovascular risk factors and with global risk, IMT being the best correlated with the Framingham score.