RATIONALE

Patients admitted to intensive care units with sepsis are prone to developing cardiac dysrhythmias, most commonly atrial fibrillation.

OBJECTIVES

To determine the incidence, risk factors, and outcomes of atrial fibrillation in a cohort of critically ill patients with sepsis.

METHODS

We assessed the association between atrial fibrillation and mortality using time-dependent competing risks survival analysis. Subsequently, for development of a risk score estimating the probability of a first occurrence of atrial fibrillation within the following 24 hours, we performed logistic regression analysis.

MEASUREMENTS AND MAIN RESULTS

Among 1,782 patients with sepsis admitted to two tertiary intensive care units in the Netherlands between January 2011 and June 2013, a total of 1,087 episodes of atrial fibrillation occurred in 418 (23%) individuals. The cumulative risk of new-onset atrial fibrillation was 10% (95% confidence interval [CI], 8-12), 22% (95% CI, 18-25), and 40% (95% CI, 36-44) in patients with sepsis, severe sepsis, and septic shock, respectively. New-onset atrial fibrillation was associated with a longer stay (hazard ratio [HR], 0.55; 95% CI, 0.48-0.64), an increased death rate (HR, 1.52; 95% CI, 1.16-2.00), and an overall increased mortality risk (subdistribution HR, 2.10; 95% CI, 1.61-2.73) when considering discharge as a competing event. A simple risk score for daily prediction of atrial fibrillation occurrence yielded good discrimination (C statistic, 0.81; 95% CI, 0.79-0.84) and calibration (chi-square, 9.38; P = 0.31), with similar performance in an independent validation cohort (C statistic, 0.80; 95% CI, 0.76-0.85).

CONCLUSIONS

Atrial fibrillation is a common complication of sepsis and independently associated with excess mortality. A simple risk score may identify patients at high risk of this complication. Clinical trial registered with www.clinicaltrials.gov (NCT 01905033).