The influence of cardiopulmonary bypass flow characteristics on the clinical outcome of 1820 coronary bypass patients.
OBJECTIVE
To determine whether pulsatile perfusion is clinically beneficial for adult cardiac operations.


METHODS
Data concerning consecutive patients undergoing isolated coronary bypass surgery (n=1820) from January 1, 1997 to July 31, 1999 were reviewed.


RESULTS
Nine hundred fifteen patients received pulsatile perfusion (PP) while perfusion in the remaining 905 patients was nonpulsatile (NP). Patients in the PP group were older (64.0 +/- 9.2 years versus 63.1 +/- 9.9 years) and experienced more of the following: urgent operations (42.4% versus 38.0%), preoperative intra-aortic balloon pump (4.8% versus 1.8%), preoperative cerebrovascular accidents (CVA; 3.1% versus 1.3%) and renal insufficiency (10.5% versus 7.0%). The PP group had higher incidence of early postoperative mortality (2.6% versus 1.5%), CVA (3.1% versus 1.3%), need for dialysis (3.2% versus 2.2%) and longer hospital stay (9.2 +/- 8.3 days versus 8.5 +/- 5.8 days). The incidence of postoperative myocardial infarction and renal dysfunction was similar in both groups (2.0% versus 2.2% and 3.3% versus 3.9% respectively; not significant). Because of the significant difference in preoperative parameters for the PP and NP groups, the following three statistical techniques were used to isolate the effect of perfusion characteristics on operative outcome: multiple regression, propensity score and risk stratification. Multivariate analysis did not find PP to be protective against mortality, morbidity and mortality, and CVA or for the development of postoperative renal dysfunction. When propensity score analysis was applied, the incidence of cardiac morbidity and mortality was strongly associated with the quintile (first quintile 6.7%, fifth quintile 27.0%, P<0.001). Multivariate analysis including quintiles did not find PP to be an independent predictor for mortality or for morbidity and mortality. Risk stratification was performed for age and for preoperative creatinine clearance levels. In all groups, PP did not seem to reduce the incidence of morbidity, morbidity and mortality, or the development of postoperative renal dysfunction. In patients with preoperative renal dysfunction, mean postoperative creatinine levels and the need for dialysis following surgery were similar in the PP and NP groups.


CONCLUSIONS
Pulsatile flow does not appear to offer any clinical benefit over nonpulsatile flow for cardiac surgery patients.
Abramov
Dan
D
Department of Cardiovascular Surgery, Sunnybrook Health Science Centre, University of Toronto, Ontario. abramov2@zahav.net.il
Tamariz
Miguel
M
Serrick
Cyril I
CI
Sharp
Edon
E
Noel
Dionne
D
Harwood
Stephen
S
Christakis
George T
GT
Goldman
Bernard S
BS
D000368:Aged; D002315:Cardiopulmonary Bypass / Q000379:methods*; D001026:Coronary Artery Bypass / Q000009:adverse effects / Q000379:methods* / Q000401:mortality; D003326:Coronary Circulation; D003404:Creatinine / Q000097:blood; D005260:Female; D018056:Hemorheology; D017052:Hospital Mortality; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011673:Pulsatile Flow; D051437:Renal Insufficiency / Q000097:blood / Q000209:etiology; D012189:Retrospective Studies; D020521:Stroke / Q000097:blood / Q000209:etiology; D016896:Treatment Outcome
D003404:Creatinine