Background: The annual incidence of sepsis is about 1.7 million in the United States and about 270,000 Americans die as a result of sepsis each year. Atrial fibrillation is the most common arrhythmia seen in hospitalized patients and has shown to unfavorably alter the cardiovascular hemodynamics in patients admitted with sepsis. However there are only limited published data on the association of AF with outcomes of elderly patients hospitalized with sepsis. So we conducted this study to analyze the association of AF with in-hospital outcomes and 30-day readmission rate following hospitalization of elderly patients with sepsis.

Methods: We queried the 2014 Nationwide Readmission Databases using the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) diagnosis codes 995.91, 995.92 to identify all patients >70 years of age hospitalized with a diagnosis of sepsis. Among these patients with sepsis, we identified the AF patients using the ICD-9-CM diagnosis code 427.31. Thirty day readmission rate was calculated in the patients who survived to discharge. Association of AF with in-hospital mortality, mean length of stay, mean hospital costs, and 30-day readmission rate following sepsis hospitalizations were analyzed after adjusting for demographics, hospital characteristics and co-morbidities, using multivariate logistic regression for categorical variables and using multivariate linear regression after log transformation for continuous variables.

Results: Of the 644,343 index sepsis hospitalizations in elderly patients (52.7% women, mean age 80±6 years), AF was documented in 208,150 (32.3%) patients and 285,872 (44.3%) patients had severe sepsis. Patients with AF in this cohort were more likely to be male, hypertensive, with kidney disease, coronary artery disease, congestive heart failure and severe sepsis. Among these elderly patients hospitalized with sepsis, in-hospital mortality was 19%, and 30-day readmission rate was 15.8%. A significant increase in in-hospital mortality (23% vs 17.1%, adjusted OR 1.24, 95% CI 1.23-1.26, p<0.001), mean length of stay (9 vs 8 days, p<0.001), hospital costs ($23,664 vs $19,082, p<0.001) and 30-day readmission rate (17.8% vs 14.9%, adjusted OR 1.15, 95% CI 1.13-1.17, p<0.001) were seen in AF patients compared to those without AF.

Conclusions: AF is associated with increase in in-hospital mortality, mean length of stay, mean hospital costs and 30-day readmission rate in elderly patients hospitalized with sepsis. AF portends a poor prognosis in elderly patients hospitalized with sepsis.