Predictors of Cardiac Troponin Release After Mitral Valve Surgery

Abstract

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. Observational study. Single-center intensive care unit. None. 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. 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). 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.