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, order (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.