(194) The Use of Direct Current Cardioversion for Unstable Atrial Fibrillation in Critically Ill Patients

Introduction: There is substantial practice variation in the management strategies for atrial fibrillation (AF) with rapid ventricular rate (RVR) and hemodynamic instability in critically ill patients. This study aimed to evaluate the use and effectiveness of direct current cardioversion (DCCV) for unstable RVR AF in the intensive care unit (ICU).

Methods: In this multicenter retrospective cohort study, we identified adult patients who developed paroxysmal RVR AF with hemodynamic instability during ICU stay in the Mayo Clinic hospitals, excluding cardiac ICUs. To compare DCCV with medical management, patients were 1:2 propensity-score matched. Primary outcomes were in-hospital mortality, hospital-, ICU-, and organ support-free days.

Results: Among 691 patients eligible for inclusion, 47 (6.8%) received emergent DCCV in ICUs. The frequency of DCCV was higher for patients located in surgical ICUs (14.5% vs 6.1%, p= 0.04). The comparative analyses were conducted on 141 patients. Those who underwent DCCV were more likely to restore sinus rhythm (SR) (odds ratio [95% confidence interval], 5.20 [1.30, 20.76]). However, DCCV was not associated with increased odds of having SR at discharge, lower mortality, or higher number of ICU-, or hospital-free days. The number of organ support-free days was significantly lower in the DCCV group (estimate ± standard error = -7.17 ± 2.04, p < 0.001; -5.03 ± 1.97, p = 0.012, respectively). The mortality rate for patients who underwent DCCV was 30%, compared to 21% in the control group (p = 0.132).

Conclusions: Emergency DCCV is rarely used to treat unstable AF in the ICU. Despite increased likelihood of immediate SR restoration, DCCV was not associated with any improvement in patient-centered outcomes. Prospective studies are warranted to evaluate harms and benefits of DCCV in critically ill patients.