Clinical prediction scores and early anticoagulation therapy for new-onset atrial fibrillation in critical illness: a post-hoc analysis

Abstract

Purpose: This study sought to describe the epidemiology of anticoagulation therapy for critically ill patients with new-onset atrial fibrillation (NOAF) according to CHA2DS2-VASc and HAS-BLED scores and to assess the efficacy of early anticoagulation therapy.

Method: Adult patients who developed NOAF during intensive care unit stay were included. We compared the patients who were treated with and without anticoagulation therapy within 48 h from AF onset. The primary outcome was a composite outcome that included mortality and ischemic stroke during the period until hospital discharge.

Results: In total, 308 patients were included in this analysis. Anticoagulants were administered to 95 and 33 patients within 48 h and after 48 h from NOAF onset, respectively. After grouping the patients into four according to their CHA2DS2-VASc and HAS-BLED bleeding scores, we found that the proportion of anticoagulation therapy administered was similar among all groups. After adjustment using a multivariable Cox regression model, we noted that early anticoagulation therapy did not decrease the composite outcome (adjusted hazard ratio [HR] 0.77; 95% confidence interval [CI] 0.47‒1.23). However, in patients without rhythm control drugs, early anticoagulation was significantly associated with better outcomes (adjusted HR 0.46; 95% CI; 0.22‒0.87, P = 0.041).

Conclusions: We found that clinical prediction scores were supposedly not used in the decision to implement anticoagulation therapy and that early anticoagulation therapy did not improve clinical outcomes in critically ill patients with NOAF. Trial registration UMIN-CTR UMIN000026401. Registered 5 March 2017.

Keywords: Anticoagulation therapy; Critical illness; Ischemic stroke; New-onset atrial fibrillation; Rhythm control therapy.

Fig. 1

Patient flow diagram. AF, atrial fibrillation; ICU, intensive care unit

Fig. 2

Anticoagulation therapy and clinical outcomes in the group divided by CHA2DS2-VASc and HAS-BLED scores. a) For anticoagulation therapy and b) for mortality and the incidence of ischemic stroke and bleeding complocations. Stroke risk was determined using the CHA2DS2-VASc score (high risk of stroke [HS] ≥ 2; low risk of stroke [LS] < 2), and bleeding risk was determined using the HAS-BLED score (high risk of bleeding [HB] ≥ 3; low risk of bleeding [LB] < 3). We divided the patients into four groups based on both risks (HS/LB, HS/HB, LS/LB, and LS/HB). Only two patients were included in the LS/HB group

Fig. 3

Primary outcome in the stratified groups. The primary outcome, which was the composite of mortality or cerebral infarction from AF onset to hospital discharge, was adjusted by the following factors: age, sex, APACHE II score, CHA2DS2-VASc score, HAS-BLED bleeding score, mechanical ventilation, renal replacement therapy, and infection at AF onset. Rhythm control drugs used during AF from the initial onset included amiodarone, pilsicainide, magnesium sulfate, and other any antiarrhythmic agents. Rate control drugs used during AF from the initial onset included diltiazem, verapamil, landiolol, propranolol, other β-blocking agents, and digoxin. AF, atrial fibrillation; DC, direct current cardioversion