title: Glycemic Control in Type 1 Diabetes and Long-Term Risk of Cardiovascular Events or Death After Coronary Artery Bypass Grafting.
abstract: BACKGROUND
  Patients with type 1 diabetes mellitus (T1DM) have a high risk of cardiovascular events.
  
  
  OBJECTIVE
  The aim of this study was to investigate whether preoperative hemoglobin A1c (HbA1c) levels could predict cardiovascular events or death after coronary artery bypass grafting (CABG).
  
  
  METHODS
  This was a nationwide population-based observational cohort study that included all patients with T1DM who underwent primary isolated nonemergency CABG in Sweden between 1997 and 2012, according to the Swedish National Diabetes Register and the SWEDEHEART (Swedish Web-system for Enhancement and Development of Evidence-based care in Heart disease Evaluated According to Recommended Therapies) register. We calculated the crude incidence rates and 95% confidence intervals (CIs) and used Cox regression and multivariable hazard ratios (HRs) to estimate the risk of both all-cause mortality and major adverse cardiovascular events (MACE), defined as myocardial infarction, stroke, heart failure, or repeat revascularization, in relation to HbA1c levels.
  
  
  RESULTS
  In total, 764 patients with T1DM were included. During a median follow-up of 4.7 years, 334 (44%) patients died or had MACE (incidence rate: 82 events/1,000 person-years). After multivariable adjustment, the HR (95% CI) for death or MACE in patients with HbA1c levels of 7.1% to 8.0%, 8.1% to 9.0%, 9.1% to 10.0%, and >10.0% were 1.34 (0.82 to 2.21), 1.59 (1.00 to 2.54), 1.73 (1.03 to 2.90), and 2.25 (1.29 to 3.94), respectively, compared with the reference category. When HbA1c was used as a continuous variable, the HR for a 1% increase in HbA1c level was 1.18, and the 95% CI was 1.06 to 1.32.
  
  
  CONCLUSIONS
  In patients with T1DM, poor glycemic control before CABG was associated with increased long-term risk of death or MACE. (HeAlth-data Register sTudies of Risk and Outcomes in Cardiac Surgery [HARTROCS]; NCT02276950).
authors.affiliation: Department of Clinical Science and Research, Karolinska Institutet, Stockholm, Sweden; Division of Internal Medicine, Södersjukhuset, Stockholm, Sweden.
authors.forename: Thomas
authors.initials: T
authors.lastname: Nyström
authors.affiliation: Department of Emergency Medicine, Karolinska University Hospital, Stockholm, Sweden; Department of Internal Medicine, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Holzmann
authors.affiliation: Institute of Medicine, University of Gothenburg, Sahlgrenska University Hospital, Gothenburg, Sweden.
authors.forename: Björn
authors.initials: B
authors.lastname: Eliasson
authors.affiliation: Department of Cardiovascular Medicine, Danderyds Hospital, Stockholm, Sweden; Department of Clinical Sciences, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Jeanette
authors.initials: J
authors.lastname: Kuhl
authors.affiliation: Department of Cardiothoracic Surgery and Anesthesiology, Karolinska University Hospital, Stockholm, Sweden; Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden. Electronic address: Ulrik.Sartipy@karolinska.se.
authors.forename: Ulrik
authors.initials: U
authors.lastname: Sartipy
mesh_terms: D000368:Aged; D001786:Blood Glucose; D002318:Cardiovascular Diseases / Q000175:diagnosis / Q000401:mortality / Q000601:surgery; D002423:Cause of Death; D016001:Confidence Intervals; D001026:Coronary Artery Bypass / Q000379:methods / Q000706:statistics & numerical data; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000453:epidemiology / Q000628:therapy; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016016:Proportional Hazards Models; D012042:Registries; D013548:Sweden / Q000453:epidemiology; D013995:Time
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin
keywords: coronary artery bypass grafting; diabetes mellitus type 1; glycosylated hemoglobin A; prognosis