Higher serum gamma-glutamyltransferase levels are independently associated with impaired coronary microvascular function in patients with dilated cardiomyopathy

Background: Patients with idiopathic dilated cardiomyopathy (IDC) have impaired coronary flow reserve (CFR) and reduced CFR has been reported to be a poor prognostic indicator and independent predictor of subsequent cardiac events in patients with IDC. Serum gamma-glutamyltransferase (GGT) level is an independent risk factor for cardiovascular disease. Therefore, we aimed to determine whether serum GGT level is associated with CFR impairment in patients with IDC. Methods: We examined 32 patients with IDC. The patients were divided into two groups based on serum GGT levels. Results: There were no significant differences between the lower and higher GGT groups regarding clinical data, baseline hemodynamics, medications and biochemical data except GGT and hsCRP levels. Subjects with higher GGT had significantly impaired CFR as compared to those with lower GGT (1.86 +/- 0.28 vs. 2.27 +/- 0.38, P = 0.002). After adjusting for potential confounders, including age, sex, body mass index, blood pressure, lipids and glucose, We found that serum GGT levels were independently associated with CFR impairment (beta = -0.48, P = 0.001). We also found that GGT level was a good predictor of low CFR at the receiver-operating characteristic curve. Area under the curve was 81% (95% CI: 0.66-0.95), and GGT level was significantly predictive of low CFR (P = 0.003). Conclusion: These results showed that there was an independent association between serum GGT level and CFR in patients with IDC. (C) 2008 Elsevier Ireland Ltd. All rights reserved.