Citoquinas e troponina-I em disfunção cardíaca após cirurgia de revascularização miocárdia com circulação extracorpórea

Abstract

Objective - The association between cytokines and troponin-I with cardiac function after cardiac surgery with cardiopulmonary bypass remains a topic of continued investigation. Methods - Serial measurements, within 24h following surgery, of tumor necrosis factor-α, its soluble receptors, and troponin-I were performed in patients with normal ejection fraction undergoing coronary artery bypass grafting. Ejection fraction was measured by radioisotopic ventriculography preoperatively, at 24h and at day 7 postoperatively. Results - Of 19 patients studied (59±8.5 years), 10 (group 1) showed no changes in ejection fraction, 53±8% to 55±7%, and 9 (group 2) had a decrease in ejection fraction, 60±11% to 47±11% (p=0.015) before and 24h after coronary artery bypass grafting, respectively. All immunological variables, except tumor necrosis factor-α soluble receptor I at 3h postoperation (5.5± 0.5 in group 1 versus 5.9±0.2 pg/ml in group 2; p=0.048), were similar between groups. Postoperative troponin-I had an inverse correlation with ejection fraction at 24h (r= -0.44). Conclusions - Inflammatory activity, assessed based on tumor necrosis factor-α and its receptors, appears to play a minor role in cardiac dysfunction after cardiac surgery. Troponin I levels are inversely associated with early postoperative ejection fraction.