title: Timing of surgery after acute myocardial infarction.
abstract: OBJECTIVE
  We wished to determine if timing of surgery, when other co-morbid variables are controlled, influenced outcome after operations for acute myocardial infarction.
  
  
  METHODS
  Between 3/20/1990 and 6/17/1994, data was prospectively collected on 338 patients undergoing operation for either evolving infarcts (n=73) or up to 21 days after infarction (mean 7.9 days).
  
  
  METHODS
  Tertiary hospital referral center.
  
  
  METHODS
  Infarction was diagnosed by CK enzymes or EKG Q-waves preoperatively in 338 patients undergoing surgery. The mean age of the patients was 66.1 years (SD+/-10.5 years), 76 had emergency operations immediately after catheterization (50 following PTCA complications), 223 had urgent operations, and 39 were elective.
  
  
  METHODS
  Seventy-three had preoperative ballon pumps, and 259 had one or more mammary artery bypasses with a mean of 3.27 (SD+/-1.0) distal anastomoses.
  
  
  RESULTS
  In-hospital and 30-day survival rate was 95.6% (323/338). Of the 73 variables evaluated by step-wise logistic regression analysis, the multivariate independent preoperative predictors of death were: aortic valve regurgitation, chronic pulmonary disease, preoperative diuretic administration, preoperative balloon pump, preoperative inotropes, and the need for additional concomitant noncardiac surgery. Including the operative variables, the predictors were: preoperative balloon pump, preoperative inotropes, the presence of left main stenosis, preoperative renal failure, chronic pulmonary disease, valve disease, ischemic arrhythmia, pump perfusion time, valve surgery, and homologous blood transfusion volume required. When the postoperative variables were included, the predictors were: preoperative inotropes, postoperative balloon pump, postoperative epinephrine, postoperative permanent stroke, and postoperative acute renal failure. The time between infarction and operation was not an independent prediction (p>0.4) in any of the logistic regression models.
  
  
  CONCLUSIONS
  Early operation after acute infarction is not in itself a risk factor, rather comorbid disease and preoperative hemodynamic status determine outcome after surgery.
authors.affiliation: Lahey Hitchcock Clinic, Department of Cardiovascular and Thoracic Surgery, Burlington, MA 08105, USA.
authors.forename: L G
authors.initials: LG
authors.lastname: Svensson
authors.forename: H
authors.initials: H
authors.lastname: Cruz
authors.forename: J
authors.initials: J
authors.lastname: Sun
authors.forename: S
authors.initials: S
authors.lastname: D'Agostino
authors.forename: W A
authors.initials: WA
authors.lastname: Williamson
authors.forename: D M
authors.initials: DM
authors.lastname: Shahian
mesh_terms: D006439:Hemodynamics; D006801:Humans; D016015:Logistic Models; D009203:Myocardial Infarction / Q000401:mortality / Q000503:physiopathology / Q000601:surgery*; D011446:Prospective Studies; D012307:Risk Factors; D015996:Survival Rate; D013997:Time Factors; D016896:Treatment Outcome