Impact of Blood Transfusion on Troponin I Levels and Outcomes after Cardiac Surgery: A Cohort Study.

OBJECTIVES

Increased cardiac troponin I (TI) has been suggested to be a sensitive indicator of intraoperative myocardial injury. We investigated the association of transfusion on TI levels post-surgery and outcomes in patients undergoing elective cardiac surgeries.

METHODS

We conducted a retrospective review of 542 patients. Patients were divided into two groups based on TI levels at 24 hours (TI24) (> 6.5 µg/L vs. ≤ 6.5 µg/L). The impact of transfusion on TI levels was estimated using logistic regression and adjusted for using a multivariable model that included aortic cross-clamp time and preoperative ejection fraction. The effect of TI on the clinical outcomes was examined.

RESULTS

Red blood cell (RBC) transfusion was found to be associated with high TI levels (odds ratio (OR) = 2.33, 0.007, 95% confidence interval (CI): 1.30-4.30). A trend was observed when aortic cross-clamp time and preoperative ejection fraction were adjusted for (OR = 2.06, 0.080, 95% CI: 0.90-4.70). An association was found between aortic cross-clamp time and high TI levels in the multivariable model (OR = 1.01, 0.028, 95% CI: 1.00-1.02). Elevated TI levels was associated with higher mortality (OR = 4.15, 0.017, 95% CI: 1.29-13.08), renal failure (OR = 2.99, 0.004, 95% CI: 1.41-6.32), and increased length of stay in-hospital (OR = 4.50, 0.020, 95% CI: 0.69-8.30).

CONCLUSIONS

RBC transfusion is associated with increased TI24 post-cardiac surgery and worse outcomes, albeit a confounding effect cannot be excluded. Larger studies are required to confirm these findings.