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, CHADS 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.