Influenza Vaccination Blunts the Inflammatory Response in Patients Undergoing Cardiopulmonary Bypass
Background
Coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB) induces an inflammatory reaction that is associated with postoperative complications. Influenza vaccination has been shown to decrease cardiovascular morbidity in patients with cardiovascular disease, possibly via its anti-inflammatory properties. We hypothesize that influenza vaccination would attenuate the inflammatory reaction after CPB.
Methods
Thirty patients undergoing CABG were blindly randomized to receive the influenza vaccine (group I, N=15) or a placebo (group II, N=15) preoperatively. Serum samples of pro-inflammatory 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, echocardiographic data and troponin levels. Other clinical outcomes were collected prospectively.
Results
Pro-inflammatory cytokine levels were significantly reduced in the treatment group [interleukin-6 (157.4 pg/dL vs 256 pg/dL, p=0.043), interleukin-8(65.03 pg/dL vs 118.56 pg/dl, p=0.025) and tumor necrosis factor(12.05 pg/dl vs 20.8 pg/dl, p=0.003)]. 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=0.008). Evidence of improved myocardial protection was observed in group I as reflected by troponin measurements postoperatively (6020.2 pg/dl vs 12098.01 pg/dl, p=0.052).
Conclusions
Influenza vaccination attenuates the inflammatory response to CPB as reflected by a reduction in the level of troponin and pro-inflammatory mediators and an increase in the anti-inflammatory cytokine interleukin-10.
