Association of carotid intima-media thickness with left main coronary artery disease.

BACKGROUND: Previous studies have shown that carotid intima-media thickness correlates well with the presence and extent of coronary artery disease. This study was conducted to determine whether it could reliably predict the presence of left main coronary artery disease. METHODS: Common carotid intima-media thickness was measured in 50 patients with angiographically proven significant (> or =50%stenosis) left main coronary artery disease and in another 50 age- and sex-matched patients with coronary artery disease without the involvement of the left main coronary artery. Measurements of the carotid intima-media thickness were made on the far wall 1 cm from the distal end of the common carotid artery bilaterally, and the average and the greater of the two values thus obtained for each patient were used for analysis. Plaques were not included in the measurement of carotid intima-media thickness. RESULTS: The average and greater of the two values were significantly higher in patients with left main coronary artery disease as compared to those without it (average intima-media thickness: 0.926 +/- 0.12 vs. 0.78 9 +/- 0.16 mm; p< 0.001; greater intima-media thickness: 0.994 +/- 0.13 vs. 0.844 +/- 0.20 mm; p< 0.001). The cut-off values of 0.81 mm for the average carotid intima-media thickness and 0.87 mm for the greater carotid intima-media thickness were found to have optimum sensitivity (92% and 90%, respectively) and specificity (60% and 64%, respectively) for the detection of left main coronary artery disease. A higher cut-off value of 1.0 mm increased specificity to 92% and 84%, respectively, for the average and greater thicknesses, but sensitivity decreased markedly. CONCLUSIONS: There is a significant association between increased carotid intima-media thickness and the presence of left main coronary artery disease. The measurement of carotid intima-media thickness can be used with reasonably good sensitivity and specificity for the detection of left main coronary artery disease in patients who are undergoing evaluation for suspectedcoronary artery disease.

Non-invasive assessment of endothelial function by brachial artery flow mediated vasodilatation and its association with coronary artery disease: an Indian perspective.

Endothelial dysfunction is the final common pathway through which various coronary risk factors culminate into atherosclerosis and subsequent coronary artery disease (CAD). Endothelial function can be reliably assessed by flow mediated vasodilatation (FMD) in the brachial artery using high-resolution ultrasonography and has been shown to be an excellent surrogate marker for the presence of CAD. Two hundred and forty-one individuals comprising of 101 patients with CAD (angiographically proven, or with history of documented myocardial infarction) and 140 individuals without CAD were included in the study. All subjects underwent clinical evaluation, fasting lipid profile, treadmill test and FMD assessment. Selected individuals underwent coronary angiography too. Brachial artery diameter and Doppler indices (systolic and diastolic velocity time integrals) were recorded using high resolution ultrasonography at baseline, immediately after and at one minute after release of cuff (occlusion time 5 minutes). FMD was calculated as percentage increase in brachial artery diameter at one minute. FMD index was calculated as the ratio of FMD and percentage increase in flow during reactive hyperaemia. Mean FMD was significantly higher in non-CAD group (8.71+/-4.77%) than in CAD group (3.77+/-2.03%; p < 0.0001). The FMD index was also significantly higher in the non-CAD group (0.031 ) than in CAD group (0.021; p=0.0117). On multiple regression analysis, FMD index was found to be significantly associated with presence of CAD (p=0.0015), independent of conventional cardiovascular risk factors. Endothelial function as assessed by FMD is significantly depressed in patients with established CAD and this association is independent of presence of conventional cardiovascular risk factors.

Carotid intima-media thickness and brachial-ankle pulse wave velocity in patients with and without coronary artery disease.

BACKGROUND: Carotid intima-media thickness and pulse wave velocity are non-invasive markers of atherosclerosis and have been shown to reliably predict presence and extent of atherosclerotic vascular disease. However, studies examining their association with each other have shown inconsistent results. Hence it was sought to assess correlation between carotid intima-media thickness and pulse wave velocity in patients with and without coronary artery disease. METHODS AND RESULTS: Sixty-four patients with angiographically proven coronary artery disease and 84 age-matched individuals without coronary artery disease but having one or more conventional cardiovascular risk factors were included in the study. Individuals with established cerebrovascular disease and peripheral vascular disease were excluded from the study. Carotid intima-media thickness of far wall was measured at three predefined sites (distal common carotid, carotid bifurcation and proximal internal carotid artery) on each side. Brachial-ankle pulse wave velocity was measured non-invasively using VP 1000 (Colin Corporation) automated ABI/ PWV analyzer. There was no significant difference in gender and presence of cardiovascular risk factors in the two groups. Mean and maximum carotid intima-media thickness and brachial-ankle pulse wave velocity were all significantly higher in coronary artery disease patients as compared to patients without coronary artery disease (0.842 v. ( 0.657 mm, p <0.0001; 1.076 v. 0.795 mm, p <0.0001; 1708.63 v. 1547.26 cm/s, p <0.0004 respectively). There was a significant correlation between brachial-ankle pulse wave velocity and both mean and maximum carotid intima-media thickness in patients with coronary artery disease (r = 0.47, p <0.0001 and r=0.41, p < 0.0008 respectively) but not in individuals without coronary artery disease (r=0.01 and -0.1 respectively). CONCLUSIONS: Presence of significant correlation between carotid intima-media thickness and brachial-ankle pulse wave velocity in patients with coronary artery disease but absence of the same in individuals without major atherosclerotic vascular disease suggests that the correlation between carotid intima-media thickness and brachial-ankle pulse wave velocity becomes stronger with increasing extent of atherosclerosis.