Abstract 8688: Incident Stroke and Mortality Associated with First-detected Atrial Fibrillation in Patients Hospitalized with Severe Sepsis

Introduction: First-detected fibrillation (AF) has been reported in 6-20% of patients with severe sepsis. Whereas chronic AF is a known risk factor for stroke and death, the clinical significance of first-detected AF in the setting of sepsis is uncertain. Our objective was to determine the in-hospital stroke and in-hospital mortality risks associated with first-detected AF in patients with severe sepsis. Hypothesis: First-detected AF during severe sepsis is associated with increased risk for in-hospital stroke and in-hospital mortality. Methods: Retrospective population-based cohort derived from 2007 California State Inpatient Database administrative claims data. Data was available from 3,147,787 hospitalized adults. Severe sepsis [N=49,082 (1.56%)] was defined by validated ICD-9-CM code 995.92. First-detected AF was defined as AF that occurred during the hospital stay, after excluding AF cases present at admission. A priori outcome measures were in-hospital ischemic stroke ( ICD-9-CM 433, 434, or 436) and mortality. Analyses of stroke and mortality outcomes were adjusted for demographics, comorbidities, and acute factors. Results: Patients with severe sepsis were 69±16 years old and 48% were women. First-detected atrial fibrillation occurred in 5.9% of patients with severe sepsis versus 0.6% of patients without severe sepsis [multivariable-adjusted odds ratio (OR), 6.82; 95% confidence interval (CI), 6.54-7.11; P <0.001]. Severe sepsis was present in 14% of all first-detected AF in hospitalized adults. Participants with severe sepsis and first-detected AF had in-hospital ischemic stroke at a rate of 34.5 (95% CI, 27.2-43.3) strokes/100 patient-years. Compared with severe sepsis patients without first-detected AF, patients with first-detected AF during sepsis had greater risks of in-hospital stroke (0.6% vs. 2.6%, adjusted OR 2.70; 95% CI, 2.05-3.57; P <0.0001) and in-hospital mortality (39% vs. 56%, adjusted relative risk, 1.07; 95% CI, 1.04-1.11; P <0.0001). Conclusion: First-detected AF during severe sepsis is associated with clinically significant adverse outcomes including higher risk of stroke and death. Investigation of strategies to decrease risks associated with incident AF during severe sepsis are warranted.