Diabetic cardiomyopathy: Pathophysiology, diagnostic evaluation and management

Abstract

Diabetes affects every organ in the body and cardiovascular disease accounts for two-thirds of the mortality in the diabetic population. Diabetes-related heart disease occurs in the form of coronary artery disease (CAD), cardiac autonomic neuropathy or diabetic cardiomyopathy (DbCM). The prevalence of cardiac failure is high in the diabetic population and DbCM is a common but underestimated cause of heart failure in diabetes. The pathogenesis of diabetic cardiomyopathy is yet to be clearly defined. Hyperglycemia, dyslipidemia and inflammation are thought to play key roles in the generation of reactive oxygen or nitrogen species which are in turn implicated. The myocardial interstitium undergoes alterations resulting in abnormal contractile function noted in DbCM. In the early stages of the disease diastolic dysfunction is the only abnormality, but systolic dysfunction supervenes in the later stages with impaired left ventricular ejection fraction. Transmitral Doppler echocardiography is usually used to assess diastolic dysfunction, but tissue Doppler Imaging and Cardiac Magnetic Resonance Imaging are being increasingly used recently for early detection of DbCM. The management of DbCM involves improvement in lifestyle, control of glucose and lipid abnormalities, and treatment of hypertension and CAD, if present. The role of vasoactive drugs and antioxidants is being explored. This review discusses the pathophysiology, diagnostic evaluation and management options of DbCM.

Keywords: Diabetic cardiomyopathy; Cardiac autonomic neuropathy; Coronary artery disease; Heart failure; Transmitral Doppler Echocardiography

Core tip: Cardiovascular disease accounts for most of the diabetes-related morbidity and mortality. Coronary artery disease (CAD), cardiac autonomic neuropathy and diabetic cardiomyopathy (DbCM) are the direct cardiac complications of diabetes. Heart failure risk is two to five times higher in diabetics than in nondiabetics. DbCM is a common, but often unrecognized, complication of diabetic heart disease. Diabetes-induced hyperglycemia, dyslipidemia and inflammation cause damage to the myocardial tissues that result in DbCM. Transmitral Doppler Echocardiography, tissue Doppler Imaging and cardiac Magnetic resonance imaging are used for diagnosis of DbCM. Management of DbCM should target healthy lifestyle, prompt control of diabetes and dyslipidemia, and treatment of hypertension and CAD, if coexistent.