title: Long-term impact of diabetes and its comorbidities in patients undergoing isolated primary coronary artery bypass graft surgery.
abstract: BACKGROUND
  The objective of this study was to identify the impact of diabetes and related comorbidities, namely chronic renal failure, peripheral vascular disease, and low ejection fraction (<35%), on long-term survival of patients undergoing coronary artery bypass graft surgery.
  
  
  RESULTS
  A unicenter study was conducted on 9125 survivors of isolated coronary artery bypass graft surgery between 1992 and 2002. There were 6581 nondiabetic patients and 2544 diabetics, including 1809 patients with noninsulin-dependent diabetes mellitus and 735 patients with insulin-dependent diabetes mellitus. Cardiac-specific survival at 5 and 10 years was lower in insulin-dependent diabetes mellitus compared with both nondiabetic mellitus patients and patients with noninsulin-dependent diabetes mellitus (P<0.0001). However, freedom from cardiac-related death was similar for patients with noninsulin-dependent diabetes mellitus and nondiabetes mellitus patients up to 6 years (P=0 0.08) after surgery and was significantly lower thereafter (P=0.004). Cardiac-specific survival after coronary artery bypass graft surgery in patients with one or more comorbidities was comparable (P=0.4) for both nondiabetes mellitus patients and patients with noninsulin-dependent diabetes mellitus, but was significantly lower for those requiring insulin therapy (P<0.0001). Noninsulin-dependent diabetes mellitus was not an independent predictor of long-term cardiac death (hazard ratio: 1.09, P=0.41); however, insulin-dependent diabetes mellitus, chronic renal failure, peripheral vascular disease, and low ejection fraction were all independent risk factors for late cardiac death (all P<0.0001). The impact of comorbidities on the long-term risk of cardiac death was similar for the 3 groups.
  
  
  CONCLUSIONS
  Noninsulin-dependent diabetes is not an independent predictor of late cardiac death after coronary artery bypass graft surgery, because cardiac-related survival is similar to that of nondiabetic patients for 6 years after surgery. In diabetic and nondiabetic patients, cardiac survival is adversely affected by the need for insulin therapy and/or the presence and number of comorbidities such as chronic renal failure, peripheral vascular disease, and low ejection fraction.
authors.affiliation: Department of Cardiac Surgery, Laval Hospital, Québec City, QC, Canada.
authors.forename: Siamak
authors.initials: S
authors.lastname: Mohammadi
authors.forename: François
authors.initials: F
authors.lastname: Dagenais
authors.forename: Patrick
authors.initials: P
authors.lastname: Mathieu
authors.forename: John G
authors.initials: JG
authors.lastname: Kingma
authors.forename: Daniel
authors.initials: D
authors.lastname: Doyle
authors.forename: Stephane
authors.initials: S
authors.lastname: Lopez
authors.forename: Richard
authors.initials: R
authors.lastname: Baillot
authors.forename: Jean
authors.initials: J
authors.lastname: Perron
authors.forename: Eric
authors.initials: E
authors.lastname: Charbonneau
authors.forename: Eric
authors.initials: E
authors.lastname: Dumont
authors.forename: Jacques
authors.initials: J
authors.lastname: Metras
authors.forename: Denis
authors.initials: D
authors.lastname: Desaulniers
authors.forename: Pierre
authors.initials: P
authors.lastname: Voisine
mesh_terms: D000368:Aged; D015897:Comorbidity; D001026:Coronary Artery Bypass; D048909:Diabetes Complications / Q000453:epidemiology* / Q000601:surgery; D003920:Diabetes Mellitus / Q000453:epidemiology* / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006331:Heart Diseases / Q000453:epidemiology / Q000601:surgery; D006801:Humans; D007676:Kidney Failure, Chronic / Q000453:epidemiology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D016491:Peripheral Vascular Diseases / Q000453:epidemiology / Q000601:surgery; D011446:Prospective Studies; D012189:Retrospective Studies; D015996:Survival Rate / Q000639:trends; D013995:Time; D016896:Treatment Outcome