Increase of renal resistive index and mineral metabolism disorder in patients with acute coronary syndrome with preserved renal function.

OBJECTIVE Coronary artery disease is one of the first causes of death in the Western world; for this reason, it is essential to identify new, systemic, non-invasive and low-cost cardiovascular risk markers. The acute coronary syndrome includes ST-Elevation Myocardial Infarction (STEMI) and Non-ST-Elevation Myocardial Infarction (NSTEMI), based on ECG findings. We aimed to evaluate Renal Resistive Index (RRI) as a marker of cardiovascular risk and assess the associations with other cardiovascular risk factors (metabolic indexes, mineral metabolism disorders and endothelial dysfunction and atherosclerosis markers) in STEMI and NSTEMI patients. PATIENTS AND METHODS Clinical, laboratory and instrumental examinations as metabolic and inflammation indexes, markers of atherosclerosis and endothelial dysfunction (renal function, mineral metabolism disorders, inflammation indexes, Intima Media Thickness (IMT), Ankle Brachial Pressure Index, Left Ventricular Mass Index, Relative Wall Thickness) were performed. RESULTS Eighty-one patients with STEMI and NSTEMI were enrolled. We showed a significant positive correlation between RRI and age (p<0.01), intact parathyroid hormone (p<0.01) and IMT (p<0.01), as well as a significant negative correlation between RRI and body surface area (BSA) (p=0.02), estimated Glomerular Filtration Rate (eGFR) (p<0.01), serum calcium (p<0.01) and 25-hydroxy-vitamin D (p=0.03). Moreover, we found a significant correlation between RRI and male patients (p<0.01), coronary artery disease history (CAD) (p=0.049), hypertension (p=0.025) and left ventricular eccentric hypertrophy (LVEH) (p=0.047). CONCLUSIONS Our study showed an association between RRI and the main traditional and non-traditional cardiovascular risk factors involved in atherosclerosis pathogenesis, such as age, BSA, hypertension, male sex, CAD history, mineral metabolism disorders and LVEH, in patients with preserved renal function. Moreover, we found a significant correlation between RRI and eGFR, suggesting that RRI could be useful in the evaluation of both renal function and progression of renal damage, even in an early stage with a conserved or only slightly reduced kidney function. We also showed a significant correlation with some markers of systemic atherosclerosis such as IMT and LVEH. For a more precise assessment of prognosis and cardiovascular risk in patients with high cardiovascular mortality, we suggest performing a systematic RRI evaluation, considering the non-invasive nature of the procedure, its reproducibility, easy execution, and low costs.