Predictors of cardiac troponin release after mitral valve surgery

Objectives: Although cardiac troponin I (cTnI) measurement is used extensively as a marker of perioperative myocardial injury, limited knowledge exists in noncoronary artery bypass graft surgery. Design: Observational study. Setting: Single-center intensive care unit. Intervention: None. Participants: One hundred eighty-five consecutive adult patients undergoing mitral valve surgery for predominant mitral regurgitation were enrolled and underwent measurement of cTnI at 24 hours after surgery. Measurements and Main Results: CTnI release after mitral valve surgery was significantly associated with an adverse outcome. The optimal cTnI value for predicting adverse outcomes was 14 ng/mL. Univariate preoperative predictors of cTnI release were prior use of diuretics (p = 0.04) or a rheumatic (p = 0.006), ischemic (p = 0.004), or myxomatous (p = 0.005) etiology to mitral disease, whereas intraoperative variables predictive of cTnI release were cross-clamp time (p = 0.005), cardiopulmonary bypass time (p < 0.001), need for mitral valve replacement (p = 0.024), number of electrical cardioversions (p = 0.03), patent foramen ovale closure (p = 0.03), tricuspid valve repair (p = 0.04), need for epinephrine/norepinephrine (p = 0.004) or intra-aortic balloon pump (p = 0.03) in the operating room; and, finally, the surgeon who performed the surgery (p = 0.014). There were no postoperative predictors of excessive cTnI release. In multivariate analysis, the only predictors of cTnI release were the cardiopulmonary bypass time (odds ratio, 1.42; confidence intervals, 1.019-1.064; p = 0.001) and the infusion of epinephrine/norepinephrine in the operating room (odds ratio, 4.002; confidence intervals, 1.238-12.929; p = 0.02). Conclusions: After mitral surgery, the need for epinephrine/norepinephrine perioperatively and the cardiopulmonary bypass time independently predict a cTnI release significantly related to an adverse outcome. (C) 2010 Elsevier Inc. All rights reserved.