Established and emerging vascular risk factors and the development of aortic stenosis: an opportunity for prevention?

Aortic valve calcification in 499 consecutive patients referred for computed tomography

INTRODUCTION

Aortic valve calcification (AVC) is the most common cause of aortic stenosis. The aim of the study was to assess the prevalence of aortic valve, coronary artery and aortic calcifications and to evaluate the correlation between calcification of the aortic valve, coronary arteries and aorta.

MATERIAL AND METHODS

The study included 499 patients aged 60 years and over who underwent coronary computed tomography because of chest pain. Beside coronary artery calcium score (CAC), we evaluated AVC and ascending aorta calcifications (AAC).

RESULTS

Aortic valve calcification was found in 144 subjects (28.9% of the whole study population). Prevalence of CAC and AAC was higher than AVC and amounted to 73.8% and 54.0%. Prevalence of AVC, CAC and AAC was significantly lower in the group of patients ≤ 70 years than in the group of patients > 70 years of age (p = 0.0002, p < 0.0001, p < 0.0001). Aortic valve calcification was more often observed in men than women (34.7% vs. 25.4%, p = 0.02). Degree of aortic valve calcification was also significantly higher among men than women (median score 4 vs. 0, p = 0.01). Similar observations were true for CAC and AAC, where both prevalence and degree of calcification was higher among men than women. In the whole study population no correlation was noted between AVC and CAC or AAC (p = 0.34, p = 0.85). There was a significant correlation between AAC and CAC (p < 0.0001).

CONCLUSIONS

Despite some similarities in pathological mechanism and risk factors, a degenerative defect of the aortic valve could be independent of atheromatous lesions in the coronary arteries and aorta.

Relation between aortic valve sclerosis and ankle-brachial index in participants clinically free of atherosclerotic vascular disease

Most patients with peripheral arterial disease (PAD) are asymptomatic and have similar vascular morbidity and mortality with patients with symptomatic PAD. Despite being a very highly prevalent disease, physicians underdiagnose and undertreat PAD. A total of 100 participants with aortic valve sclerosis (AVS) and 100 participants without AVS and age-, gender-, and cardiovascular risk factor-matched participants were enrolled. Ankle-brachial index (ABI) and AVS were evaluated by handheld Doppler device and echocardiography, respectively. There was significantly lower ABI in participants with AVS compared with those without AVS (1.04 ± 0.14 v 1.11 ± 0.07, P = .001). There was a negative correlation between ABI and AVS (r = -.29, P < .001). Linear regression analysis demonstrated an independent association between ABI and AVS (95% confidence interval [CI]: -0.91 to -0.27, P < .001) and β-blocker use (95% CI: -0.96 to -0.02, P: .04). Our findings confirm an association between AVS and PAD that may be attributed to shared vascular risk factors.

The relationship between severity of calcific aortic stenosis and serum uric acid levels

Serum uric acid (SUA) level is a marker of endothelial dysfunction and oxidative stress. Consecutive patients (n = 64) with normal coronary angiography who demonstrated calcific aortic stenosis (AS) by transthoracic echocardiography were included in the study. The patients were categorized into 3 groups: 23 mild AS (12 males), 21 moderate AS (10 males), and 20 severe AS cases (10 males). Fasting SUA level was significantly higher in the severe AS group than in the moderate and mild AS groups (severe AS, 6.3 ± 1.6; moderate AS, 4.9 ± 1.3; mild AS; 4.6 ± 1.4 mg/dL; P < .001, respectively). There was a positive correlation between SUA level and maximum as well as mean aortic gradient (r = .521, P < .001 and r = .526, P < .001, respectively). There was a negative correlation between SUA level and aortic valve area (r = -.447, P < .001). Levels of SUA were increased in calcific AS cases. In addition, there was a positive correlation between severity of calcific AS and SUA levels.

Correlation of Peroxisome Proliferator-Activated Receptor-gamma (PPAR-gamma) and Retinoid X Receptor-alpha (RXR-alpha) expression with clinical risk factors in patients with advanced carotid atherosclerosis

Background

Peroxisome proliferator-activated Receptor-γ (PPAR-γ) and its nuclear partners, the Retinoid X Receptors (RXRs), have been recognized as crucial players in the pathogenesis of atherosclerosis. The present study aimed to assess the clinical significance of PPAR-γ and RXR-α expression in different cellular populations localized within advanced carotid atherosclerosis lesions.

Material/Methods

PPAR-γ and RXR-α expression was assessed by immunohistochemistry ïn 134 carotid atherosclerotic plaques obtained from an equal number of patients that underwent endarterectomy procedure for vascular repair, and was correlated with patients’ medical history, risk factors and medication intake.

Results

Increased incidence of low PPAR-γ expression in both macrophages and smooth muscle cells was noted in patients presenting coronary artery disease (p=0.032 and p=0.046, respectively). PPAR-γ expression in smooth muscle cells was borderline down-regulated in symptomatic compared to asymptomatic patients (p=0.061), reaching statistical significance when analyzing groups of patients with specific cerebrovascular events; amaurosis fugax (p=0.008), amaurosis fugax/stroke (p=0.020) or amaurosis fugax/transient ischemic attack patients (p=0.028) compared to asymptomatic patients. Low RXR-α expression in macrophages was more frequently observed in hypertensive (p=0.048) and hyperlipidemic patients (p=0.049). Increased incidence of low RXR-α expression in smooth muscle cells was also noted in patients presenting advanced carotid stenosis grade (p=0.015).

Conclusions

PPAR-γ and RXR-α expression down-regulation in macrophages and smooth muscle cells was associated with a more pronounced disease progression in patients with advanced carotid atherosclerotic lesions.

Aortic stenosis and lipids: does intervention work?

PURPOSE OF REVIEW

Aortic stenosis is a common disorder affecting increasing numbers of elderly patients, which is associated with markedly increased cardiovascular morbidity and mortality. Both histological and epidemiological studies have suggested that the process of valve degeneration may resemble atherosclerosis. This review investigates the potential role of lipid-lowering therapy in its management.

RECENT FINDINGS

The current treatment methods are surgical or endovascular intervention but it has been hoped that antiatherosclerotic therapies might result in a reduction in progression and need for intervention. There have been a number of retrospective studies of lipid-lowering therapy, which suggested that statins might be effective in reducing progression of aortic stenosis. Lately a series of trials of aggressive statin therapy on surrogate markers of progression have shown no benefit from these measures. The controversial Simvastatin-Ezetimibe and Aortic Stenosis (SEAS) endpoint trial did not show any benefit on a combined endpoint of valve-related and ischaemic events but hinted at a reduction in cardiovascular events in this high cardiovascular risk group.

SUMMARY

The data clearly shows statins have little effect in well established stenotic disease with calcification, but their effects earlier in the disease process (aortic valve sclerosis) remain to be determined.

Association between carotid and coronary artery disease in patients with aortic valve stenosis: an angiographic study

BACKGROUND

Patients with aortic stenosis have a high prevalence of coronary artery disease, but there is little information about the association of coronary artery disease and carotid artery disease.

METHODS

The study includes 317 consecutive patients with aortic stenosis, who underwent carotid and coronary angiography during the same catheterization before aortic valve replacement.

RESULTS

At univariate analysis, the prevalence of coronary artery disease was associated with (1) presence of carotid artery disease (P < .001); (2) angina pectoris as presentation symptom (P < .001); (3) age more than 65 years (P < .05); and (4) hypertension (P < .05). At multivariate analysis, only carotid artery disease, angina, and age emerged as independent predictors of coronary artery disease. The combination of 2 variables (carotid artery disease, angina) allowed the identification of 4 groups, with decreasing prevalence of coronary artery disease: (1) angina+/carotid artery disease+: 85%; (2) angina-/ carotid artery disease+: 50%; (3) angina+/carotid artery disease-: 41%; (4) angina-/carotid artery disease-: 21% (P < .001).

CONCLUSION

In patients with symptomatic aortic stenosis, the presence of significant carotid artery disease is a strong marker of significant coronary artery disease.