Plasma mitochondrial DNA level as an early marker of systemic inflammatory response syndrome and organ failure in patients undergoing cardiac surgery

Aim. To assess whether plasma mitochondrial DNA (mtDNA) levels in the early postoperative period can predict the development of systemic inflammatory response syndrome (SIRS) and multiple organ failure in patients undergoing cardiac surgery. Methods. This pilot, prospective, observational, cohort study included 85 patients undergoing cardiac surgery. Plasma mtDNA levels were determined immediately after the surgery, and the development of SIRS, acute kidney injury, acute heart failure, and adult respiratory distress syndrome was assessed. Results. The mtDNA levels showed good potential for predicting the development of SIRS within 1-2 days after the surgery (area under the curve = 0.74). Regarding the cut-off point, a mtDNA level of >0.54 ng/mL predicted the development of SIRS in the early postoperative period with a sensitivity of 73.7% and a specificity of 66%. The odds ratio for the development of acute kidney injury with/without SIRS was 3.4 [confidence interval (CI) = 1.279.08; p = 0.0149]; acute heart failure, 5.7 (CI = 2.20-14.84; p = 0.0003); and adult respiratory distress syndrome, 3.6 (CI = 1.01-11.10; p = 0.047). Conclusion. The plasma mtDNA levels in the early postoperative period can be used as a predictive marker for the development of SIRS and multiple organ failure in patients undergoing cardiac surgery. Moreover, SIRS is associated with the development of acute kidney injury, acute heart failure, and adult respiratory distress syndrome. Received 25 March 2019. Revised 3 April 2019. Accepted 8 April 2019.