Cross-clamp time is an independent predictor of mortality and morbidity in low- and high-risk cardiac patients

Objectives: We sought to assess the effects of aortic cross-clamp time (XCL) on outcome following cardiac surgery in low-and high-risk patients. Methods: This is a retrospective review of prospectively collected departmental data of all patients who underwent cardiac surgery over 8-year period. Our cohort consisted of 3799 consecutive patients subdivided into low-risk (Euro SCORE <6, n = 2691, 71%) and high-risk (Euro SCORE >= 6, n = 1108, 29%). Each class was further stratified into three groups based on their corresponding XCL time. Group 1 (XCL <= 60 min), group 2 (XCL > 60 but <= 90 min) and group 3 (XCL > 90 min). Postoperative morbidity and in-hospital mortality were analysed. Results: Univariate analysis showed the following to be significantly associated with increased XCL time in both low-and high-risk patients: low cardiac output, prolonged ventilation time, renal complications, prolonged hospital stay, blood transfusion and increased mortality (p < 0.05). By using multiple logistic regression, aortic XCL time > 60 min was independent risk factor for low cardiac output, prolonged ventilation, renal complication, blood transfusion, mortality and prolonged hospital stay in both groups. By using XCL time as a continuous variable, an incremental increase of 1 min interval in XCL time was associated with a 2% increase in mortality in both groups. Conclusion: Prolonged cross-clamp time significantly correlates with major post-operative morbidity and mortality in both low-and high-risk patients. This effect increases with increasing XCL time. Prior knowledge on this effect can help in preventing some of these complications. (C) 2010 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved.