Pre-Diabetes Increases Stroke Risk in Patients With Nonvalvular Atrial Fibrillation

BACKGROUND Diabetes mellitus (DM) increases the risk of embolism in nonvalvular atrial fibrillation (NVAF). The association between pre-diabetes and risk of ischemic stroke has not been studied separately in this population. OBJECTIVES The purpose of this study was to evaluate whether pre-diabetes is associated with increased risk of stroke and death in patients with NVAF. METHODS We conducted a historical cohort study using the Clalit Health Services electronic medical records. The study population included all members aged >= 25 years, with a first diagnosis of NVAF between January 1, 2010, and December 31, 2016. We compared 3 groups of individuals: those with pre-diabetes, those with diabetes, and normoglycemic patients. RESULTS A total of 44,451 cases were identified. The median age was 75 years, and 52.5% were women. During a mean follow-up of 38 months, the incidence rates of stroke (per 100 person-years) were: 1.14 in normoglycemic individuals, 1.40 in those with pre-diabetes, and 2.15 in those with diabetes. In both univariate and multivariate analyses, pre-diabetes was associated with an increased risk of stroke compared with normoglycemic persons (adjusted hazard ratio [adjHR]: 1.19; 95% confidence interval [CI]: 1.01 to 1.4) even after adjustment for CHA(2)DS(2)-Vasc risk factors and use of anticoagulants, while diabetes conferred an even higher risk (vs. normoglycemia (adjHR: 1.56; 95% CI: 1.37 to 1.79). The risk for mortality was higher for individuals with diabetes (adjHR: 1.47; 95% CI: 1.41 to 1.54) but not for those with pre-diabetes (adjHR: 0.98; 95% CI: 0.92 to 1.03). CONCLUSIONS In this cohort of patients with incident NVAF, pre-diabetes was associated with an increased risk of stroke even after accounting for other recognized risk factors. (C) 2021 by the American College of Cardiology Foundation.

Automated summary

Pre-diabetes is associated with an increased risk of stroke in patients with nonvalvular atrial fibrillation (NVAF), even after adjustment for other risk factors. Diabetes confers an even higher risk of stroke compared to normoglycemic individuals. Mortality risk is higher in individuals with diabetes but not in those with pre-diabetes.