New-onset atrial fibrillation in severe sepsis and risk of stroke and death: a critically appraised topic

Abstract

Background: Severe sepsis has been associated with an increased risk of new-onset arrhythmias, namely atrial fibrillation (AF). Single-center and small-center studies suggest that new-onset AF is associated with higher mortality and prolonged hospitalization during severe sepsis. However, the relationship between new-onset AF in severe sepsis to prognosis is unknown.

Objective: To determine whether new-onset AF increases the risk of stroke and death in severe sepsis.

Methods: The objective was addressed through the development of a structured, critically appraised topic. This incorporated a clinical scenario, background information, a structured question, literature search strategy, critical appraisal, results, evidence summary, commentary, and bottom-line conclusions. Participants included consultant and fellow-level neurologists, a medical librarian, clinical epidemiologists, and context experts in the fields of vascular neurology, hospital neurology, critical care medicine, and cardiovascular medicine.

Results: A recent retrospective, population-based cohort study was selected and appraised to address this prognostic question. Patients were obtained from the California State Inpatient Database administrative claims data from nonfederal acute care hospitals from January 1 through December 31, 2007. Of the 3,144,787 patients, 49,082 (1.56%) had severe sepsis, defined by the validated International Classification of Disease, 9th Revision, Clinical Modification code 995.92. The a priori outcome measures included in-hospital ischemic stroke and mortality. New-onset AF occurred in 5.9% of patients with severe sepsis versus 0.65% of patients without severe sepsis [odds ratio, 6.82; 95% confidence interval (CI), 6.52-7.11; P<0.001]. Compared with severe sepsis patients without new-onset AF, patients with new-onset AF during severe sepsis had greater risks of in-hospital ischemic stroke (2.6% vs. 0.6% strokes; adjusted odds ratio, 2.70; 95% CI, 2.05-3.57; P<0.001) and in-hospital mortality (56% vs. 39% deaths; adjusted relative risk, 1.07; 95% CI, 1.04-1.11; P<0.001). Findings were robust across 2 separate definitions of severe sepsis and multiple sensitivity analyses.

Conclusions: In patients with severe sepsis, new-onset AF seems to increase the risk of in-hospital stroke and mortality compared with patients with no or preexisting AF.