MODIFYING RISK FOR EXTRACORPOREAL-CIRCULATION - TRIAL OF 4 ANTIINFLAMMATORY STRATEGIES

Background. Despite recent rediscovery of beating heart cardiac surgic al techniques, extracorporeal circulation remains appropriate for most heart operations. To minimize deleterious effects of cardiopulmonary bypass, antiinflammatory strategies have evolved. Methods. Four state- of-the-art strategies were studied in a prospective, randomized, preop eratively risk stratified, 400-patient study comprising primary (n = 3 58), reoperative (n = 42), coronary (n = 307), valve (n = 27), ascendi ng aortic (n = 9), and combined operations (n 23). Groups were as foll ows: standard, roller pump, membrane oxygenator, methylprednisolone (n = 112); aprotinin, standard plus aprotinin (n = 109); leukocyte deple tion, standard plus a leukocyte filtration strategy (n 112); and hepar in-bonded circuitry, centrifugal pumping with surface modification (n = 67). Results. Analysis of variance, linear and logistic regression, and Pearson correlation were applied. Actual mortality (2.3%) was less than half the risk stratification predicted mortality (5.7%). The tre atment strategies effectively attenuated markers of the inflammatory r esponse to extracorporeal circulation. Compared with the other groups the heparin-bonded circuit had highly significantly decreased compleme nt activation (p = 0.00001), leukocyte filtration blunted postpump leu kocytosis (p = 0.043), and the aprotinin group had less fibrinolysis ( p 0.011). Primary end points, length of stay, and hospital charges, we re positively correlated with operation type, age, pump time, body sur face area, stroke, pulmonary sequelae, predicted risk for stroke, pred icted risk for mortality, and risk strata/treatment group interaction (p 0.0001). In low-risk patients, leukocyte filtration reduced length of stay by 1 day (p = 0.02) and mean charges by $2,000 to $6,000 (p = 0.05). For high-risk patients, aprotinin reduced mean length of stay u p to 10 fewer days (p = 0.02) and mean charges by $6,000 to $48,000 (p = 0.0007). Conclusions. These pharmacologic and mechanical strategies significantly attenuated the inflammatory response to extracorporeal circulation. This translated variably into improved patient outcomes. The increased cost of treatment was offset for selected strategies thr ough the added value of significantly reduced risk. (Ann Thorac Surg 1 998;66:747-54) (C) 1998 by The Society of Thoracic Surgeons.