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 U 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.