Measurement of Troponin T and I to detect cardioprotective effect of aminophylline during coronary artery bypass grafting.
The aim of the present study was to evaluate the possibility that aminophylline could serve as a potential myocardial protectant by measuring cardiac troponin T (TnT) and troponin I (TnI) during coronary artery bypass grafting (CABG). Twenty patients were randomly divided into two groups. Ten patients received aminophylline, 200 mg orally per day for 3 days preoperatively (aminophylline group, AG), and 10 patients received placebo (control group, CG). Blood samples were collected before induction of anesthesia (T0), after 30 min of aortic cross clamping (ACC) (T1), and 1, 24, and 48 h postoperatively (T2, T3, T4). Serum concentrations of TnT, TnI, and creatine kinase-MB (CK-MB) were measured. Perioperative hemodynamic data were recorded and cardiac hemodynamics were evaluated by echocardiography preoperatively and 5-7 days after surgery. There were no adverse events in either group. Preoperative serum levels of TnT and TnI were similar. Their concentrations increased after T1 and, peaked at T2 (0.50+/-0.30 vs. 0.30+/-0.40 ng/ml, and 0.50+/-0.30 vs. 7.90+/-2.70 ng/ml, respectively, P<0.001), and progressively declined until T4. The CK-MB levels of both groups also supported these results. After completion of cardiopulmonary bypass (CPB), the serum concentrations of all enzymes in both groups were significantly higher than before CPB (P<0.001), and serum TnT and TnI levels were significantly lower at T1, T2, T3, and T4 in AG (P<0.001). There was no significant difference in echocardiographic data, cardiac index, ejection fraction or any other hemodynamic parameter between the groups. Fewer patients needed inotropic support (one vs. three patients) (P=0.6) and experienced atrial fibrillation (AF) (one vs. four patients) (P=0.3) in the AG after surgery, although not statistically significant. Although there was no statistically valid evidence to indicate that aminophylline improved clinical outcome in this study, several biochemical endpoints suggested that it reduced I-R damage at the cellular level, and such subtle improvement could be clinically significant in high-risk patients.
Department of Thoracic and Cardiovascular Surgery, Faculty of Medicine, Hacettepe University, Ankara, Turkey. sk2249@columbia.edu
Sadi
S
Kaplan
Kanat
K
Ozisik
Jeffrey A
JA
Morgan
Riza
R
Dogan