Predictors for sustained new-onset atrial fibrillation in critically ill patients: a retrospective observational study.

Abstract

Although new-onset atrial fibrillation (AF) is frequently observed in the intensive care unit (ICU), the incidence and predictors for sustained new-onset AF have not been investigated, except for cardiac surgery patients. We have evaluated potential predictors for sustained new-onset AF in a mixed ICU. In this retrospective observational study, we screened non-cardiac surgery patients who were admitted to the ICU between January 2010 and December 2013 and had been hospitalized for > 24h in the ICU. We collected information about heart rhythm 6h after the onset of AF. We compared detailed patient characteristics between patients with sinus rhythm (SR) and those with sustained AF at 6h after the onset of AF. Additionally, we applied variable selection using backward elimination based on Akaike's Information Criterion (AIC). Calibration was performed based on the Hosmer-Lemeshow test. New-onset AF occurred in 151 of 1718 patients and 99 patients converted to SR at 6h. Backward elimination identified predictors as follows (AIC = 175.3): CHADS2 score, elective surgery, infection on ICU admission, serum potassium > 4.0mmol/L, male sex, mechanical ventilation, and diagnostic grouping. The model showed good calibration for sustenance of AF at 6h after the onset using the Hosmer-Lemeshow Chi-square value of 4.36 (degrees of freedom = 4, p = 0.360) indicating a good fit. These predictors might be useful in future interventional studies to identify patients who are likely to sustain new-onset AF.