title: An unexpected inverse relationship between HbA1c levels and mortality in patients with diabetes and advanced systolic heart failure.
abstract: BACKGROUND
  In diabetes, poor glycemic control, as indexed by hemoglobin A1c (HbA1c), is associated with increased risk of cardiovascular events and new-onset heart failure (HF). However, in patients with diabetes and HF, the relationship between glucose control and survival has not been investigated. Our study aimed to evaluate the relationship between HbA1c levels and mortality in patients with diabetes and advanced systolic HF.
  
  
  METHODS
  We studied a cohort of 123 patients with diabetes and advanced systolic HF referred to a single center with HbA1c values measured at presentation. The patients were grouped based on HbA1c: HbA1c < or = 7.0 (n = 49) and HbA1c > 7.0 (n = 74).
  
  
  RESULTS
  The cohort was 70% men, ejection fraction of 25% +/- 7, 59% ischemic etiology, HbA1c 7.9 +/- 1.8, and diabetes duration of 8.6 +/- 9.0 years. The HbA1c groups were similar in age; sex; New York Heart Association class; body mass index; diabetes duration; and insulin, metformin, and glitazone use. HbA1c > 7.0 was associated with higher ejection fraction, increased beta-blocker, and sulfonlyurea use. Patients with HbA1c < or = 7.0 had significantly increased all-cause mortality, compared with those with HbA1c > 7.0 (35% vs 20%, hazard ratio 2.6, 95% CI 1.3-5.2, P < .01). In multivariate analysis, HbA1c < or = 7.0 remained associated with increased mortality (hazard ratio 2.3, 95% CI 1.0-5.2).
  
  
  CONCLUSIONS
  Paradoxically, elevated HbA1c levels were associated with improved survival in this cohort of patients with diabetes and advanced HF. Further investigation is necessary to determine the nature of this relationship and optimal HbA1c in patients with diabetes and HF.
authors.affiliation: Cedars Sinai Medical Center, Los Angeles, CA, USA.
authors.forename: Shervin
authors.initials: S
authors.lastname: Eshaghian
authors.forename: Tamara B
authors.initials: TB
authors.lastname: Horwich
authors.forename: Gregg C
authors.initials: GC
authors.lastname: Fonarow
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D048909:Diabetes Complications / Q000097:blood* / Q000150:complications / Q000401:mortality* / Q000503:physiopathology; D018450:Disease Progression; D005260:Female; D006442:Glycated Hemoglobin; D006333:Heart Failure / Q000097:blood* / Q000150:complications / Q000401:mortality* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011498:Protein Precursors / Q000097:blood*; D015996:Survival Rate; D013599:Systole
chemical_list: D006442:Glycated Hemoglobin; D011498:Protein Precursors; C040839:pre-hemoglobin A, glycosylated