Microvascular Coronary Dysfunction in a Woman With Signs and Symptoms of Myocardial Ischemia but No Obstructive Coronary Artery Disease

Abstract

Women with signs and symptoms of myocardial ischemia often have no obstructive coronary artery disease by invasive coronary angiography when compared to men. Microvascular coronary dysfunction (MCD) is thought to be a key contributory mechanism for myocardial ischemia in women with chest pain and no obstructive CAD. We report a case of a 53-year-old post-menopausal female with hyperlipidemia evaluated for persistent chest pain following a non-ST elevation myocardial infarction (NSTEMI) and no obstructive CAD by coronary angiography. Vital signs and physical examination were within normal limits. Prior EKG showed diffuse abnormal T wave inversion and flattening in anterior and inferior leads. Echocardiography demonstrated an ejection fraction of 72% with no regional wall motion abnormalities. Laboratory values revealed a positive heterozygote factor V Leiden mutation. Given the constellation of persistent chest pain, no obstructive CAD, and prior NSTEMI, a diagnosis of MCD was suspected and she underwent coronary reactivity testing (CRT) with intracoronary infusions of adenosine, acetylcholine, and nitroglycerin to test non-endothelial and endothelial dependent, micro-and macrovascular coronary function. CRT results were consistent with a diagnosis of MCD. A statin and angiotensin converting enzyme inhibitor was added to her existing treatment of beta-blocker and nitrates. Additionally, she was started on warfarin therapy due to a positive factor V Leiden in the setting of prior NSTEMI. Her symptoms improved at one-month follow-up and she is currently asymptomatic by selfreport. In women with signs and symptoms of myocardial ischemia and no obstructive CAD, it is important to identify and diagnose MCD, as inadequate diagnosis is associated with an increased risk of adverse cardiovascular events including myocardial infarction, congestive heart failure, and sudden cardiac death. Identification of MCD and clinical awareness are vital for optimal medical therapy and reduced CVD risk. Clinical trials testing efficacy of traditional and novel interventions are needed in MCD populations.