Predictors of low cardiac output syndrome after isolated aortic valve surgery.
BACKGROUND
Low cardiac output syndrome (LCOS), defined as the need for postoperative intraaortic balloon pump or inotropic support for >30 minutes in the intensive care unit, remains a relatively common complication of aortic valve (AV) surgery. The aim of this study is to identify the preoperative predictors of LCOS in patients undergoing isolated AV surgery.


RESULTS
We conducted a retrospective review of data prospectively entered into an institutional database. Between 1990 and 2003, 2255 patients underwent isolated AV surgery with no other concomitant cardiac surgery. The independent predictors of LCOS and operative mortality (OM) were determined by stepwise logistic regression analysis. The overall prevalence of LCOS was 3.9%. The independent predictors of LCOS were (odds ratio in parentheses) renal failure (5.0), earlier year of operation (4.4), left ventricular ejection fraction <40% (3.6), shock (3.2), female gender (2.8), and increasing age (1.02). Overall OM was 2.9%. The OM was higher in patients who experienced LCOS (38% versus 1.5%; P<0.001). The independent predictors of mortality were (odds ratio in parentheses) preoperative renal failure (8.3), urgency of surgery (3.4), previous stroke (2.9), congestive heart failure (2.6), previous cardiac surgery (2.3), hypertension (1.7), and small AV size (1.3).


CONCLUSIONS
Low-output syndrome is associated with significantly increased morbidity and mortality. Novel strategies to preserve renal function, optimization of preexisting heart failure symptoms, and avoidance of prosthesis-patient mismatch may reduce the incidence of LCOS and lead to improved results after AV surgery.
Maganti
Manjula D
MD
Division of Cardiovascular Surgery, Toronto General Hospital, University of Toronto, Ontario, Canada.
Rao
Vivek
V
Borger
Michael A
MA
Ivanov
Joan
J
David
Tirone E
TE
D000368:Aged; D001021:Aortic Valve / Q000601:surgery*; D002303:Cardiac Output, Low / Q000188:drug therapy / Q000453:epidemiology* / Q000209:etiology / Q000601:surgery; D002316:Cardiotonic Agents / Q000627:therapeutic use; D003422:Critical Care; D016208:Databases, Factual; D005260:Female; D006801:Humans; D007423:Intra-Aortic Balloon Pumping; D007676:Kidney Failure, Chronic / Q000150:complications; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011183:Postoperative Complications / Q000188:drug therapy / Q000453:epidemiology* / Q000209:etiology / Q000601:surgery; D015995:Prevalence; D011446:Prospective Studies; D012189:Retrospective Studies; D012307:Risk Factors; D013318:Stroke Volume; D016896:Treatment Outcome
D002316:Cardiotonic Agents