Preoperative C-reactive protein predicts respiratory infection after coronary artery bypass graft surgery

Increased levels of high-sensitive C-reactive protein (hsCRP) in the preoperative evaluation for coronary artery bypass graft surgery (CABG) have been associated to poor outcomes in the postoperative period.

To evaluate the association of high levels of hsCRP with short-term outcomes after cardiac surgery.

Prospective cohort with 331 patients who underwent CABG surgery with cardiopulmonary bypass (CPB) at our Institution. Patients were assigned to two groups according to hsCRP levels, measured before surgery: normal (N group) with <3 mg/l hsCRP; and increased (A group) with ≥ 3 mg/l hsCRP. This cutoff of 3 mg/l had a sensitivity and specificity of 60% for predicting respiratory infection, with a power of 90%. The patients were followed-up during the in-hospital period.

The mean age was 60 years, and 71.6% of the patients were male. HsCRP was increased (group A) in 144 patients (43.5%). In-hospital mortality was 4.8% and the most frequent complications in both groups were: overall infections (18%), respiratory infections (16%), atrial fibrillation (15%) and acute myocardial infarction (7.6%). The incidence of postoperative overall infections was 14.4% in the N group and 23.6% in the A group (P=0.046). Respiratory infections were also more frequent in the A group (21.5% vs. 11.8%; p = 0.024). Multivariate analyses showed that hsCRP level represented an independent predictor of postoperative respiratory infection (OR=2.08, 95% IC = 1.14-3.79).

High preoperative hsCRP level is an independent predictor of respiratory infections in the mid-term postoperative period of elective coronary artery bypass graft surgery.