Assessment coronary flow reserve in patients with end stage liver disease

In patients with end stage liver disease cardiac function seems to be normal at rest, however under conditions of pharmacological or physiological stress, cardiac function is impaired. Cirrhotic cardiomyopathy is a clinical syndrome with a variety of underlying pathogenetic mechanisms including abnormalities in beta adrenergic signaling pathway, defects in cardiomyocyte plasma membrane, increased level of cytokines. The role of coronary microvascular dysfunction in the development of cirrhotic cardiomyopathy remains unknown. The assessment of coronary flow reserve (CFR) by transthoracic echocardiography is a noninvasive method to evaluate microvascular dysfunction. In this study we aimed to evaluate coronary microvascular dysfunction by assessing CFR in patients with end stage liver disease. Thirthy eight cirrhotic patients with no coronary artery disease or diabetes mellitus and 32 healthy subjects were examined. Coronary flow was measured with pulsed Doppler from mid to distal part of the left anterior descending artery at baseline and after dipiridamol infusion in hyperemic condition. CFR was calculated as the ratio of hyperemic to baseline peak diastolic flow velocity. The mean age of the patients was 44.0 ± 11.2 and there were no differences in age and sex between patients and controls. The incidence of coronary artery disease risk factors like hypertension, hyperlipidemia, smoking and history of familial coronary artery disease were also similar between the two groups. When compared with the control group mean CFR was lower in cirrhotic patients (2.01 ± 0.31 ve 2.84 ± 0.62; p<0.0001). Increasing age, increased myocardial mass, high AST and ALT, low hemoglobin, high CFR, decreased cholesterol and platelet levels were found to be associated with the reduction in CFR. However among all these factors only the hemoglobin level and age were independent predictors for impaired CFR. CFR is impaired in end stage liver disease. This finding points out coronary microvascular dysfunction in cirrhotic patients. The coronary microvascular dysfunction can potentially contribute to the development of cirrhotic cardiomyopathy and atherosclerotic heart disease in these patients.