title: In-hospital mortality and long-term survival after coronary artery bypass surgery in young patients.
abstract: OBJECTIVE
  Coronary artery bypass graft (CABG) is performed for symptomatic and prognostic reasons. We aimed to determine the factors that contribute to in-hospital mortality and long-term survival in young patients (aged less than 65) undergoing CABG.
  
  
  METHODS
  A prospective database was retrospectively analysed and cross-correlated with the United Kingdom's Strategic Tracing Service to evaluate survival in patients under the age of 65, following isolated primary CABG. Univariate-, multivariate logistic with Cox regression- and neural network analyses were performed.
  
  
  RESULTS
  Patients under the age of 65, who had undergone isolated CABG between April 1997 and March 2010 were studied;n = 5967. In-hospital mortality was 1.1% and long-term mortality was 13.5%; median follow-up 7.9 years. Multivariate analysis demonstrated that atrial fibrillation, 'urgent' operation status, postoperative creatinine kinase (CKMB), moderate or poor left ventricular (LV) function, and female sex were significant factors predicting in-hospital mortality. Cox regression demonstrated that age, diabetes (oral and insulin controlled), moderate and poor LV function, cerebrovascular disease, dialysis, left internal mammary artery (LIMA) usage, postoperative CKMB, atrial fibrillation, 'urgent' operation status, and peripheral vascular disease were significant factors determining long-term survival. Radial artery use, off-pump surgery, composite arterial grating and graft number had no effect on in-hospital mortality or long-term survival. Neural network analysis confirmed the factors identified by logistic and Cox multivariate analysis.
  
  
  CONCLUSIONS
  The risk factors for in-hospital mortality in patients under the age of 65 include postoperative CKMB, urgent operation status, LV function, female sex and atrial fibrillation. Significant factors determining long-term survival in the under-65 age group include age, atrial fibrillation, diabetes (diet and insulin controlled), LV function, cerebrovascular disease, dialysis, LIMA usage, 'urgent' operation status, CKMB and peripheral vascular disease.
authors.affiliation: Department of Cardiac Surgery, Liverpool Heart and Chest Hospital, Liverpool, UK.
authors.forename: Neeraj
authors.initials: N
authors.lastname: Mediratta
authors.forename: John
authors.initials: J
authors.lastname: Chalmers
authors.forename: Mark
authors.initials: M
authors.lastname: Pullan
authors.forename: James
authors.initials: J
authors.lastname: McShane
authors.forename: Mathew
authors.initials: M
authors.lastname: Shaw
authors.forename: Michael
authors.initials: M
authors.lastname: Poullis
mesh_terms: D000704:Analysis of Variance; D019295:Computational Biology; D001026:Coronary Artery Bypass / Q000401:mortality*; D016208:Databases, Factual; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D016571:Neural Networks, Computer; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012044:Regression Analysis; D012189:Retrospective Studies; D006113:United Kingdom / Q000453:epidemiology