Abstract 3350: Plasminogen Activator Inhibitor-1 as a Predictor of Postoperative Atrial Fibrillation Following Cardiopulmonary Bypass
Background: Postoperative atrial fibrillation (AF), leading to significant morbidity and prolongation of hospital stay, complicates 20% to 40% of surgical procedures requiring cardiopulmonary bypass (CPB). This study tests the hypothesis that inflammatory markers predict the development of postoperative AF.
Methods and Results: We enrolled 253 adult patients undergoing elective cardiac surgery requiring CPB and who were in sinus rhythm at the time of surgery. Blood samples were obtained for measurement of inflammatory markers immediately after separation from CPB and administration of protamine. Patients who developed postoperative AF (67 subjects, 26.5%) were significantly older (P<0.001), more likely to have a remote history of AF (P<0.001) and tended to be more likely to have had valve surgery (P=0.082). Plasminogen activator inhibitor-1 (PAI-1, 17.2±1.2 ng/mL versus 14.6±0.7 ng/mL, P=0.014), interleukin(IL)-6 (380.6±151.1 pg/mL versus 174.8±16.9 pg/mL, P=0.019) and N-terminal prohormone brain natriuretic peptide (248.2±63.2 pg/mL versus 182.0±30.6 pg/mL, P=0.028) concentrations were significantly higher in the blood of patients who developed postoperative AF. Logistic regression identified age (P<0.001), remote history of AF (P=0.001), and PAI-1 (P=0.032) as independent predictors of postoperative AF. The Chi-squared Automatic Interaction Detection (CHAID) model indicated that age was the primary determinant for the development of postoperative AF (17% in age ≤67.3 years versus 49% in age >67.3 years). Within younger patients (age ≤67.3 years) without remote history of AF, PAI-1 antigen concentration next determined risk of AF (13% if PAI-1 ≤28.5 ng/mL versus 46% if PAI-1 >28.5 ng/mL). PAI-1 antigen concentration correlated with CPB time (P=0.008), age (P=0.005), body mass index (P<0.001) and IL-6 (P=0.001).
Conclusion: An elevated postoperative PAI-1 antigen concentration is an independent predictor for development of AF following CPB. Studies are needed to determine whether drugs that reduce PAI-1 concentrations can also reduce the risk of postoperative AF.