Riassunto analitico
The prevalence of coronary artery disease is significantly higher in HIV-infected patients compared to the general population, traditional and non traditional risk factors are involved, but the specific mechanisms remain unknown. However recent studies have shown that in HIV patients persistent immune activation and inflammation play a major role in the pathogenesis of cardiovascular disease with atherosclerosis characterized by atypical, high risk plaques. On histological analysis an unstable plaque contains a large lipid core, a thin fibrous cap, areas of micro-calcification and a substantial infiltration of inflammatory cells. Recent CT (Computed Tomography) angiography studies in HIV infected patients have demonstrated that these patients have a greater number of unstable plaques, larger plaque volume, a greater number of segments with plaque and non-calcified plaques than the general population. Calcification is a key feature of atherosclerosis and its macroscopic presence can be detected by cardiac computed tomography in the coronary arteries. Coronary Artery Calcium (CAC) is a sensitive marker of subclinical atherosclerosis, it is strongly associated with coronary atherosclerotic burden and it is a sensitive predictor of future cardiovascular events. Prediction can be improved by examining the progression of CAC; however with CT imaging to detect CAC it is currently impossible to identify the presence of high-risk plaques prone to rupture that eventually lead to acute myocardial infarction. Recent data show that PET (Positron Emission Tomography) imaging with 18F-Na helps determining whether a plaque is actively accumulating calcium and phosphorus and that this characteristic is an indication of plaque instability. Accordingly, we propose to investigate the relationship between CAC seen on CT and 18F-Na uptake on PET imaging in a cohort of HIV infected patients followed in the Metabolic Clinic at the University of Modena and Reggio Emilia. In addition we aim to study whether there is a relationship between coronary atherosclerosis activity assessed with PET and systemic inflammation and immune activation detected with different biomarkers.
We propose to utilize the new PET-CT 18F-Na technology to study a cohort of 50 HIV infected patients attending the Modena HIV Metabolic Clinic (MHMC) who underwent a cardiovascular risk stratification with two coronary CT scans at lest one years apart.
For this study the enrolment phase will last for about 48 weeks. Each patient will undergo a single visit during which it will be performed a clinical evaluation, a blood test and PET analysis.
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