Triglyceride Deposit Cardiomyovasculopathy Manifesting Coronary Artery Disease

Abstract

Coronary artery disease (CAD) is a leading cause of death worldwide, despite the recent remarkable progress in medical and interventional remedies. Cholesterol is an established causal factor and therapeutic target for CAD; however, the role of triglyceride (TG) in atherogenesis remains unknown. Triglyceride deposit cardiomyovasculopathy (TGCV) is a novel disease concept that was first reported in patients who required cardiac transplantation in 2008. Defective intracellular lipolysis of TG results in cellular steatosis and energy failure mainly in smooth muscle cells and cardiomyocytes. Patients with TGCV exhibit unique TG-deposit atherosclerosis, with diffuse narrowing of concentric stenosis in advanced cases. These pathological characteristics are different from those of classic cholesterol-induced atherosclerosis, which shows focal and eccentric stenosis. The Japan TGCV study group developed the diagnostic criteria for TGCV, in which a low washout rate of ¹²³I-β-methly-p-iodophenyl pentadecanoic acid in myocardial scintigraphy is an essential item. Patients with TGCV often complain of atypical cardiovascular symptoms and are resistant to cholesterol-lowering therapy and percutaneous coronary intervention with second-generation drug-eluting stents. Our recent registry study reported low 5-year overall and cardiovascular event-free survival rates in previously diagnosed patients. However, the administration of tricaprin to facilitate myocardial lipolysis of TG has been reported to regress diffuse atherosclerotic lesions in some cases of TGCV. Notably, a substantial number of patients with TGCV exist (most remain undiagnosed) in the population with acute and chronic CAD. In this review, we briefly present the disease concept, pathophysiology, diagnosis, and clinical characteristics of TGCV.