Investigation of the Use of Bilirubin Oxidation as a Screening Test for Coronary Artery Disease

Abstract

Coronary artery disease (CAD) is a common cause of death in Japan, causing about 200,000 deaths each year . The use of percutaneous coronary intervention (PCI) and coronary artery bypass graft (CABG) have reportedly improved patient outcomes since their introduction . Thus, early detection and treatment for CAD may further reduce the mortality rate. Asymptomatic CAD occurs in 15% of patients aged <70 years and in 28% of those aged >70 years . Therefore, a highly sensitive screening method is required to detect CAD in these individuals. Some studies report that stress testing with electrocardiography, echocardiography, and scintigraphy monitoring, and the use of coronary computed tomography (CT) to measure the coronary calcium level are useful for CAD screening . However, these tests are expensive and time-consuming in some clinical settings, which reduces their feasibility. Repeated myocardial ischemia-reperfusion (MIR) occurs in patients with CAD, wherein intermittent blood fl ow restriction is followed by re-canalization . Reperfusion and reoxygenation after myocardial ischemia cause the release of a large number of reactive oxygen species (ROS) . We have focused on the oxidative stress that occurs in MIR. Serum bilirubin is part of the biological defense system that is activated in response to the presence of ROS . After reoxygenation, ROS rapidly oxidize Original Article