Neither endothelial function nor carotid artery intima-media thickness predicts coronary computed tomography angiography plaque burden in clinically healthy subjects: a cross-sectional study

Correlation of carotid artery reactivity with cardiovascular risk factors and coronary artery vasodilator responses in asymptomatic, healthy volunteers

OBJECTIVES

Carotid artery reactivity (CAR%), involving carotid artery diameter responses to a cold pressor test (CPT), is a noninvasive measure of conduit artery function in humans. This study examined the impact of age and cardiovascular risk factors on the CAR% and the relationship between CAR% and coronary artery vasodilator responses to the CPT.

METHODS

Ultrasound was used to measure resting and peak carotid artery diameters during the CPT, with CAR% being calculated as the relative change from baseline (%). We compared CAR% between young (n = 50, 24 ± 3 years) and older participants (n = 44, 61 ± 8 years), and subsequently assessed relationships between CAR% and traditional cardiovascular risk factors in 50 participants (44 ± 21 years). Subsequently, we compared left anterior descending (LAD) artery velocity (using transthoracic Doppler) with carotid artery diameter (i.e. CAR%) during the CPT (n = 33, 37 ± 17 years).

RESULTS

A significantly larger CAR% was found in young versus older healthy participants (4.1 ± 3.7 versus 1.8 ± 2.6, P < 0.001). Participants without cardiovascular risk factors demonstrated a higher CAR% than those with at least two risk factors (2.9 ± 2.9 versus 0.5 ± 2.9, P = 0.019). Carotid artery diameter and LAD velocity increased during CPT (P < 0.001). Carotid diameter and change in velocity correlated with LAD velocity (r = 0.486 and 0.402, P < 0.004 and 0.02, respectively).

CONCLUSION

Older age and cardiovascular risk factors are related to lower CAR%, while CAR% shows good correlation with coronary artery responses to the CPT. Therefore, CAR% may represent a valuable technique to assess cardiovascular risk, while CAR% seems to reflect coronary artery vasodilator function.

Dyslipidemia and cardiovascular changes in children

PURPOSE OF REVIEW

In this review, we firstly highlight the role of dyslipidemia as a trigger in the initiation and progression of endothelial dysfunction, considered the earliest atherosclerotic lesion and patent in children with risk factors.In this context, we also revise methods that reflect the impact of endothelial dysfunction not only on arterial stiffness but also on cardiovascular morphology, namely, the common carotid intima-media thickness and the ventricular geometry.

RECENT FINDINGS

In view of its atherogenic burden, the most widely studied lipoprotein has been low density lipoprotein cholesterol. However, the smaller, denser, low density lipoprotein cholesterol particles, the nonhigh density lipoprotein cholesterol fraction, appear to be more atherogenic and a more sensitive cardiovascular risk marker. Studies have shown that in children, atherogenic lipids have also been linked to cardiovascular morphological changes, such as the common carotid intima-media thickness and the ventricular geometry, both independent cardiovascular risk markers.

SUMMARY

In infancy, atherosclerosis is a preclinical disorder in which dyslipidemia plays a crucial role. Due to its impact on cardiovascular structures, potentially reversible during childhood, dyslipidemia ought to be managed aggressively to prevent further disease progression that will ultimately culminate in cardiac disease, a leading cause of mortality in adults.

Regular physical activity and cardiovascular biomarkers in prevention of atherosclerosis in men: a 25-year prospective cohort study

Background

The purpose of the study was to examine the association between leisure-time physical activity (LTPA), cardiovascular biomarkers and atherosclerosis among asymptomatic men with stable LTPA level throughout the 25-year prospective observation.

Methods

Out of 101 asymptomatic men prospectively observed for their lifestyle and cardiovascular risk factors, the cohort of 62 individuals (mean age 59.9 years) maintained a stable LTPA level during the 25-year observation. Regular check-ups with the assessment of traditional risk factors, detailed measurements of LTPA level and aerobic capacity were performed since baseline. At the latest follow-up (2011/12) a set of cardiovascular biomarkers was measured using enzyme-linked immunosorbent assay. Subclinical atherosclerosis was assessed by means of coronary artery calcification score and intima-media thickness (IMT). Endothelial function was evaluated by means of the reactive hyperemia index. The studied biomarkers and indices were analyzed in the three cohorts representing stable low-tomoderate (<2050 kcal/week), high (2050-3840 kcal/week) and very high LTPA (>3840 kcal/week).

Results

At baseline the three cohorts were comparable in terms of age and clinical characteristics. At follow-up, the cohort with stable high LTPA (2050-3840 kcal/week) had significantly lower concentrations of hs-CRP (2.20 ± 1.0 mg/L), oxidized-LDL (68.35 ± 67.7 ng/mL), leptin (4.71 ± 3.07 ng/mL) and irisin (0.47 ± 0.13 μmol/L), and the most favorable indices of atherosclerosis and endothelial function as compared with other groups (p < 0.05). Regular marathon runners had increased concentrations of hsCRP (3.12 ± 1.4 mg/L), oxidized-LDL (249.8 ± 129 ng/ml), Interleukine-6 (3.74 ± 2.4 pg/ml). A positive correlation was observed between hsCRP and IMT (r = 0.301; p < 0.01), and irisin and IMT (r = 0.223; p < 0.05).

Conclusions

The data suggest that stable high LTPA (2050-3840 kcal/week) is associated with the most favorable profile of key cardiovascular biomarkers and indices of atherosclerosis. Lifetime very high LTPA is associated with increased lowgrade inflammation and may, therefore, exert an atherogenic effect.

Use of imaging and clinical data to screen for cardiovascular disease in asymptomatic diabetics

Background

There is increasing evidence to suggest that not all individuals with type 2 diabetes mellitus (T2DM) have equal risk for developing cardiovascular disease. We sought to compare the yield of testing for pre-clinical atherosclerosis with various approaches.

Methods

98 asymptomatic individuals with T2DM without known coronary artery disease (CAD) were enrolled in a prospective study and underwent carotid ultrasound, exercise treadmill testing (ETT), coronary artery calcium (CAC) scoring, and coronary computed tomography angiography (CTA).

Results

Of 98 subjects (average age 55 ± 6, 64 % female), 43 (44 %) had coronary plaque detectable on CTA, and 38 (39 %) had CAC score >0. By CTA, 16 (16 %) had coronary stenosis ≥50 %, including three subjects with CAC = 0. Subjects with coronary plaque had greater prevalence of carotid plaque (58 % vs. 38 %, p = 0.01) and greater carotid intima media thickness (0.80 ± 0.20 mm vs. 0.70 ± 0.11 mm, p = 0.02). Notably, 18 of 55 subjects (33 %) with normal CTA had carotid plaque. Eight subjects had a positive ETT, of whom five had ≥ 50 % coronary stenosis, two had <50 % stenosis, and one had no CAD. Among these tests, CAC scoring had the highest sensitivity and specificity for prediction of CAD.

Conclusion

Among asymptomatic subjects with T2DM, a majority (56 %) had no CAD by CTA. When compared to CTA, CAC was the most accurate screening modality for detection of CAD, while ETT and carotid ultrasound were less sensitive and specific. However, 33 % of subjects with normal coronary CTA had carotid plaque, suggesting that screening for carotid plaque might better characterize stroke risk in such patients.