Treatment of new-onset atrial fibrillation in noncardiac intensive care unit patients: a systematic review of randomized controlled trials.

OBJECTIVE: Atrial fibrillation is a common problem associated with morbidity and mortality in critically ill patients; however, evidence-based treatment recommendations are lacking. The objective of this systematic review was to evaluate the efficacy of pharmacologic rhythm control of new-onset atrial fibrillation in noncardiac, critically ill adults. DATA SOURCE: Citations identified from an electronic search of Medline, the Cochrane register of controlled trials, and Embase databases (1966 to August 2006) were independently reviewed by two investigators. STUDY SELECTION: All prospective randomized controlled trials evaluating pharmacologic rhythm conversion regimens for new-onset atrial fibrillation in (noncardiac surgery) critically ill adult patients were included. The primary end point was atrial fibrillation resolution. DATA EXTRACTION: Using a standardized data extraction form, data related to study design, population characteristics, pharmacologic intervention, and outcome measures were collected. DATA SYNTHESIS: Four trials met inclusion criteria from 1995 citations screened. Of the 143 evaluable patients in these trials 89 (76%) had atrial fibrillation while the remaining ones had other atrial tachyarrhythmias. Drugs evaluated for rhythm conversion included amiodarone (n = 26), procainamide (n = 14), magnesium (n = 18), flecainide (n = 15), esmolol (n = 28), verapamil (n = 15), and diltiazem (n = 27). The definition of treatment success ranged from conversion within 1 hr to conversion within 24 hrs. No study evaluated maintenance of conversion, and one study included hemodynamically unstable patients. Lack of methodologic homogeneity prevented any pooled analysis.
CONCLUSIONS: Using the current published literature, we cannot recommend a standard treatment for atrial fibrillation in noncardiac critically ill adult patients. Clinical trials evaluating rhythm conversion in critically ill populations outside of cardiac surgery are lacking. Further trials that address goals of care in hemodynamically stable and unstable patients and utilize standardized definitions of successful cardioversion are required.