Hyperglycemia on admission and hospitalization outcomes in patients with atrial fibrillation

Background: We evaluated the association of admission blood glucose (ABG) and mortality in patients with and without diabetes mellitus (DM) hospitalized for atrial fibrillation (AF). Hypothesis: Hyperglycemia on admission is a bad prognostic marker in patients with AF. Methods: Observational data were collected from electronic records of patients age ≥ 18 years hospitalized for AF in 2011–2013. Twelve-month data were available in all cases. ABG levels were classified as follows: 70 to 110 mg/dL, normal; 111 to 140 mg/dL, mildly elevated; 141 to 199 mg/dL, moderately elevated; ≥200 mg/dL, markedly elevated. Cox proportional hazards model was used to assess overall survival by ABG categories, adjusted for study variables. Primary outcome measure was mortality at end of follow-up. Results: The cohort included 1127 patients (45% male; median age, 75 ± 13 years), of whom 331 had DM. Mortality rates by ABG levels were 19% (77/407 patients), normal ABG; 26% (92/353 patients), mildly elevated ABG; 28% (69/244 patients), moderately elevated ABG; and 41% (50/123 patients), markedly elevated ABG. Data were analyzed for the entire cohort following adjustment for age, sex, CHADS₂ score, ischemic heart disease, smoking, and alcohol consumption. Compared with normal ABG, the adjusted hazard ratio for mortality was higher in patients with moderately elevated ABG (2.1, 95% confidence interval: 1.19-7.94, P < 0.05) and markedly elevated ABG (1.6, 95% confidence interval: 1.02-5.31, P < 0.05). Conclusions: In patients with and without DM hospitalized for AF, moderately to markedly elevated ABG levels are associated with increased mortality.