Lipoprotein a: Extreme Elevation and Genetic Polymorphism Association with Cardiac and Vascular Lesions Evaluated by Computed Tomography

Abstract

Background: Lipoprotein a [Lp(a)] has a complex structure, similar to low density lipoprotein, associated with one molecule of apolipoprotein a [apo(a)]. Elevated plasma levels of Lp(a) are related to greater risk of coronary artery disease and calcification of the aortic valve. This risk is mainly determined by genetic factors. Objectives: The aim of this study was to analyze a group of patients with extreme Lp(a) levels [>100 mg/dL] and their association with calcifications of the aortic valve, coronary arteries and thoracic aorta detected by computed tomography scan, and to evaluate three genetic polymorphisms associated with Lp(a) levels and lesions in these three regions. Methods: rs10455872 and rs2048327 polymorphisms were analyzed in 40 patients using high resolution melting and the number of KIV-2 repeats in the LPA gene was evaluated using quantitative PCR. Patient mean age was 52.9 years (37% women) and mean Lp(a)was 170.4 mg/dL. Results: Seventy-five percent of patients (30/40) presented at least one calcification in the computed tomography scan (valves, coronary arteries and/or thoracic aorta), and among them, 90% had at least one of the genetic factors associated with Lp(a) pathogenicity. Conclusion: In a group of patients with elevated Lp(a) levels, we found a significant number of cardiovascular thoracic calcifications and genetic determinants associated with different Lp(a) isoforms that could be related with elevated Lp(a)levels and high risk of developing valve or vascular lesions.