Perioperative heart-type fatty acid binding protein levels in atrial fibrillation after cardiac surgery

Background: Postoperative atrial fibrillation (POAF) is common and associated with poor outcomes. Perioperative ischemia can alter arrhythmic substrate. Objective: To demonstrate an association between perioperative measurements of heart-type fatty acid binding protein (HT-FABP), a sensitive marker of ischemic myocardial injury. Methods: Blood samples from 63 inpatients undergoing coronary artery bypass surgery, valve surgery, or both were obtained before and up to 4 days after surgery. Continuous telemetry monitoring was used to detect POAF. Fifty-nine patients had at least 3 HT-FABP measurements. The relationship of enzyme-linked immunosorbent assay-measured HT-FABP with POAF was assessed by using joint logistic regression adjusted for age and surgery type. Results: Thirty-five patients (55%) developed POAF; these were, on average, older (69.3±10 years vs 60±11 years; P =.0019), with a higher prevalence of heart failure (43% vs 17%; P =.034), chronic obstructive lung disease (26% vs 4%; P =.017), preoperative calcium channel blocker use (29% vs 7%; P =.031), and more likely to undergo combined surgery (21% vs 11%, P =.049). The joint age- and coronary artery bypass surgery-adjusted model revealed that postoperative but not preoperative HT-FABP levels predicted POAF (coefficient 1.9±0.87; P =.03). Longer bypass time, prior infarction, and worse renal function were all associated with higher postoperative HT-FABP. Conclusions: A greater rise of HT-FABP is associated with atrial fibrillation after cardiac surgery, suggesting that ischemic myocardial damage is a contributing underlying mechanism. Interventions that decrease perioperative ischemic injury may also decrease the occurrence of POAF.