Abstract 14822: Lipoprotein (a) is a Residual Risk Factor of Aortic Valve Calcification in Patients With High Risk of Atherosclerotic Disease

Abstract

Introduction: The number of patients with aortic valve stenosis which results from aortic valve calcification (AVC), has been increasing in the elderly population. The risk factors of AVC include diabetes, dyslipidemia, and hypertension. However, control of these risk factors has not resulted in a decreased incidence of AVC. Increased Lipoprotein (LP) (a) and oxidized low-density lipoprotein (LDL), or decreased omega 3-fatty acids, are the candidates for serum biomarkers of residual risk factors. However, the most contributable risk factors for AVC has not been identified. Methods: We enrolled a total of 618 patients who underwent coronary angiography by computed tomography because of suspicion of coronary artery disease (CAD). Calcium scores were calculated using imaging software (3mensio Medical Imaging) and existence of coronary stenosis was evaluated. Patients who were suspected of having significant coronary stenosis underwent coronary angiography to confirm the existence of ischemic heart disease. Patients were evaluated for residual risk factors including Lp(a), oxidized LDL, omega 3- and 6-fatty acids, and C-reactive protein in addition to markers of conventional risk factors. Result: The calcium score in patients who received aortic valve replacement was significantly higher than that in patients who did not undergo AVR. There were no difference between the calcium scores in patients with CAD and those without CAD. Univariate analysis showed that the calcium score was associated with levels of Lp(a) (P<0.01) but not with omega 3- and 6-fatty acids, oxidative LDL, hemoglobin A1c, LDL- and HDL-cholesterol, triglycerides, and C-reactive protein. Multivariate analysis showed that increased Lp(a) and age were independently correlated with the calcium score (P<0.01), but sex and the existence of other conventional risk factors including hypertension, dyslipidemia, and chronic kidney disease were not. Conclusion: Serum Lp(a) is a potent risk factor for AVC in patients with high risk of atherosclerosis. Lowering Lp(a) may be a potential strategy for prevention of AVC. Intervention studies involving methods of lowering Lp(a) are needed to confirm the results.