Influenza Vaccination Blunts the Inflammatory Response in Patients Undergoing Cardiopulmonary Bypass

Abstract

Coronary artery bypass grafting with cardiopulmonary bypass (CPB) induces an inflammatory reaction that is associated with postoperative complications. Influenza vaccination has been shown todecrease cardiovascular morbidity in patients withcardiovascular disease, possibly via its anti-inflammatoryproperties. We hypothesize that influenza vaccination would attenuate the inflammatory reaction after CPB. Thirty patients undergoing coronary artery bypass grafting were blindly randomized to receive the influenza vaccine (group I, n= 15) or a placebo (group II, n= 15) preoperatively. Serum samples of proinflammatory mediators (interleukin-6, interleukin-8, tumor necrosis factor, C-reactive protein) as well as the anti-inflammatory interleukin-10 were collected at different time points perioperatively. Assessment of myocardial dysfunction was investigated by measuring hemodynamic data, echocardiographic data, and troponin levels. Other clinical outcomes were collected prospectively. Proinflammatory cytokine levels were significantly reduced in the treatment group vs the placebo group (interleukin-6 [157.4 pg/dL vs 256 pg/dL, P= .043], interleukin-8 [65.03 pg/dL vs 118.56 pg/dL, P= .025], and tumor necrosis factor [12.05 pg/dL vs 20.8 pg/dL, P= .003]). These differences were observed at the end of CPB and persisted for 2 days postoperatively. Interestingly, the level of the anti-inflammatory marker interleukin-10 was significantly higher in group I (83.3 pg/dL vs 15.15 pg/dL, P= .008). Evidence of improved myocardial protection was observed in group I, as reflected by troponin measurements postoperatively (6020.2 pg/dL vs 12,098.01 pg/dL, P= .052). Influenza vaccination attenuates the inflammatory response to CPB as reflected by a reduction in the level of troponin and proinflammatory mediators and an increase in the anti-inflammatory cytokine interleukin-10.