Modifying risk for extracorporeal circulation: trial of four antiinflammatory strategies.
BACKGROUND
Despite recent rediscovery of beating heart cardiac surgical 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, preoperatively risk stratified, 400-patient study comprising primary (n = 358), reoperative (n = 42), coronary (n = 307), valve (n = 27), ascending aortic (n = 9), and combined operations (n = 23). Groups were as follows: standard, roller pump, membrane oxygenator, methylprednisolone (n = 112); aprotinin, standard plus aprotinin (n = 109); leukocyte depletion, standard plus a leukocyte filtration strategy (n = 112); and heparin-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 treatment strategies effectively attenuated markers of the inflammatory response to extracorporeal circulation. Compared with the other groups the heparin-bonded circuit had highly significantly decreased complement activation (p = 0.00001), leukocyte filtration blunted postpump leukocytosis (p = 0.043), and the aprotinin group had less fibrinolysis (p = 0.011). Primary end points, length of stay, and hospital charges, were positively correlated with operation type, age, pump time, body surface area, stroke, pulmonary sequelae, predicted risk for stroke, predicted 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 up 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 through the added value of significantly reduced risk.
Department of Biostatistics, Emory University, Carlyle Fraser Heart Center, Crawford Long Hospital of Emory University, Atlanta, Georgia 30365, USA.
J P
JP
Gott
W A
WA
Cooper
F E
FE
Schmidt
W M
WM
Brown
C E
CE
Wright
J D
JD
Merlino
J D
JD
Fortenberry
W S
WS
Clark
R A
RA
Guyton
D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use; D007611:Aprotinin / Q000627:therapeutic use; D002315:Cardiopulmonary Bypass / Q000191:economics / Q000379:methods*; D013504:Cardiovascular Surgical Procedures / Q000191:economics; D005845:Georgia; D006490:Hemostatics / Q000627:therapeutic use; D017722:Hospital Charges; D006801:Humans; D007902:Length of Stay; D007958:Leukocyte Count; D008297:Male; D008775:Methylprednisolone / Q000627:therapeutic use; D011183:Postoperative Complications / Q000517:prevention & control*; D011446:Prospective Studies; D012044:Regression Analysis; D018570:Risk Assessment
D000894:Anti-Inflammatory Agents, Non-Steroidal; D006490:Hemostatics; D007611:Aprotinin; D008775:Methylprednisolone