Estudio de la función endotelial mediante tomografía por emisión de positrones en pacientes con hipercolesterolemia / Endothelial function assessment by positron emission tomography in patients with hypercholesterolemia

Hypercholesterolemia prompts to endothelial dysfunction (ED) and ED predisposes to atherogenesis. ED appears early in the course of atherogenesis and it is considered a coronary artery disease (CAD) marker. OBJECTIVES: To assess endothelial function (EF) using Positron Emission Tomography (PET) in asymptomatic patients with recent dyslipidemia diagnosis and without history of ischemic heart disease and previous hypolipemiant treatment. MATERIAL AND METHODS: Fourteen asymptomatic patients with recent dyslipidemia diagnosis (< 6 months) were studied by obtaining a lipid profile, blood glucose, and a three phase 13N-ammonia PET scan: rest, cold pressor test (CPT) and pharmacologic stress with adenosine. EF was assessed by calculating the coronary flow reserve (CFR), endothelial-dependant vasodilatation index (EDVI), and coronary blood flow increase percentage in CPT (% Delta CF). RESULTS: 79% of patients with dyslipidemia had ED and all their values were lower than those previously published as normal: rest coronary flow 0.44 +/- 0.12 vs 0.57 +/- 0.147 (p = 0.002), CPT coronary flow 0.57 +/- 0.17 vs 0.88 +/- 0.26 (p = 0.001), stress coronary flow 1.24 +/- 0.05 vs 1.81 +/- 0.35 (p = 0.005), EDVI 1.28 +/- 0.25 vs 1.53 +/- 0.24 (p 0.017), CRF 2.79 +/- 0.94 vs 3.15 +/- 0.48 (p 0.198) and % Delta CF 29.08 +/- 24.62% vs 53 +/- 24.60% (p 0.022). Conclusions: Asymptomatic patients in early stages of dyslipidemia showed a greater ED prevalence that was detected by 13N-ammonia PET scan.

Tomografía computada multidetector de arterias coronarias: estado del arte. Parte I: aspectos técnicos / Computer multidetector tomography of coronary arteries: state-of-the-art. Part 1: technical aspects

The study of atherosclerotic disease in coronary arteries is fundamental since it is the first cause of death in the Western hemisphere. The gold standard for its diagnosis is invasive angiography, but it contributes to an increase in costs for this group of patients. Nowadays fourth generation computed tomography (CT) equipments can construct acquisition data of up to 256 images in only 400 milliseconds (ms), which is 900 to 1000 times faster than first generation apparatus. CT multidetector (CTMD) is the noninvasive choice diagnosis method for a vascular evaluation of the thorax. Its role in the study of the heart was limited, but today it is possible to obtain three-dimensional heart and whole body images in only seconds. CTMD is a fast, low-cost, noninvasive method that generates cardiac and extra cardiac images without adjacent structure interference. The higher temporal resolution due to an increase of the gantry's rotation and new reconstruction algorithms, as well as its higher spatial resolution and elevated time acquisition due to the presence of more detectors, have permitted CTMD to give significantly better and precise diagnosis of coronary arteries.