Oxidized phospholipids and lipoprotein-associated phospholipase A_2 as important determinants of Lp(a) functionality and pathophysiological role

Lipoprotein（a） [Lp（a）] is composed of a low density lipoprotein（LDL）-like particle to which apolipoprotein（a）[apo（a）] is linked by a single disulfide bridge. Lp（a） is considered a causal risk factor for ischemic cardiovascular disease（CVD） and calcific aortic valve stenosis（CAVS）. The evidence for a causal role of Lp（a） in CVD and CAVS is based on data from large epidemiological databases, mendelian randomization studies, and genome-wide association studies. Despite the well-established role of Lp（a） as a causal risk factor for CVD and CAVS, the underlying mechanisms are not well understood. A key role in the Lp（a） functionality may be played by its oxidized phospholipids（OxPL） content. Importantly, most of circulating OxPL are associated with Lp（a）; however, the underlying mechanisms leading to this preferential sequestration of OxPL on Lp（a） over the other lipoproteins,are mostly unknown. Several studies support the hypothesis that the risk of Lp（a） is primarily driven by its OxPL content.An important role in Lp（a） functionality may be played by the lipoprotein-associated phospholipase A_2（Lp-PLA_2）,an enzyme that catalyzes the degradation of OxPL and is bound to plasma lipoproteins including Lp（a）. The present review article discusses new data on the pathophysiological role of Lp（a） and particularly focuses on the functional role of OxPL and Lp-PLA_2 associated with Lp（a）.

Tetralogy of Fallot with Absent Pulmonary Valve and Pulmonary Artery Aneurysm:A Case Report of Surgical Cure

Absent pulmonary valve is a rare congenital anomaly, characterized with a dysplastic or absent pulmonary valve tissue and severe pulmonary regurgitation. It is usually associated with tetralogy of Fallot （TOF）. A 7-year-old girl with absent pulmonary valve, pulmonary artery aneurysm and tetralogy of Fallot without cyanosis was operated and 10 months followed up result was reported

Incidence of coronary artery disease before valvular surgery in isolated severe aortic stenosis

Background Angina pectoris has been recognized as one of the principal symptoms of aortic valve stenosis （AS）,even in patients without significant coronary artery disease （CAD）.However,the incidence of angina pectoris and related CAD in such patients is controversial.There is continuing debate as to whether coronary angiography is necessary before aortic valve replacement （AVR） in patients with severe AS.The purpose of this study was to evaluate the incidence and predictors of CAD in patients with severe AS in a Korean population.Methods Data from all consecutive patients with severe AS undergoing AVR at a major tertiary cardiac and vascular center in Korea were entered in a prospective registry beginning in 1995.Clinical and echocardiographic follow-up data were recorded into the database annually.Significant CAD was defined as one or more major coronary arteries having an estimated narrowing of ≥70％ and left main coronary arteries having an estimated narrowing of ≥50％ on coronary angiography.We excluded patients with multiple valve disease,significant aortic regurgitation,or prior CAD or valve surgery.Results Totally 574 patients with severe AS （mean age,（65.9±9.6） years） were enrolled in this study.Significant CAD was found in 61 patients （10.6％）.Factors associated with increased likelihood of CAD were age,hypertension,diabetes mellitus,chronic renal failure,carotid disease,and aorta calcification.In Logistic regression analysis,the independent predictor of the presence of CAD was age （P=0.011）.The incidence of CAD increased significantly at 69.2 years of age.Having two risk factors for cardiovascular disease was the most useful cutoff to predict whether a patient was going to have significant CAD.Conclusions There was a low incidence of significant CAD in a population of Korean patients with severe AS.Therefore,coronary angiography before AVR will be considered in patients with multiple risk factors for cardiovascular disease or in patients more than 69 years of age without risk factors for cardiovascular disease.