# Early vs. Late Anticoagulation in Acute Ischemic Stroke for Non-Atrial Fibrillation Indications

## TL;DR

This study compares early and late anticoagulation timing in stroke patients without atrial fibrillation, finding that early anticoagulation may reduce risks.

## Contribution

The study provides guidance on anticoagulation timing for non-AF stroke patients, an area with limited prior research.

## Key findings

- Early anticoagulation was not linked to higher bleeding risks.
- Late anticoagulation increased composite risks of bleeding, stroke recurrence, and mortality.
- The secondary outcome showed higher rates in the late cohort (43.8% vs. 15.4%).

## Abstract

In persons whose sole indication for anticoagulation is atrial
fibrillation (AF), early therapeutic anticoagulation after acute ischemic
stroke (AIS) may decrease ischemic risk without increasing hemorrhagic risk.
However, literature to guide anticoagulation timing in patients with a
non-AF indication remains extremely limited.

This retrospective cohort study compared outcomes of early (within
≤4 days of AIS) versus late anticoagulation (5–14 days) for
persons with AIS and non-AF indications for anticoagulation. The primary
outcome was a composite of intracranial hemorrhage or major extracranial
bleeding while on therapeutic anticoagulation, within 30 days of the index
event. The main secondary outcome was a composite of major bleeding events
while on therapeutic anticoagulation, recurrent AIS, systemic embolism, and
all-cause mortality, within 30 days of the index event.

Eighty-one patients were included for analysis, with 65 patients in
the early cohort and 16 patients in the late cohort; median time to
anticoagulation was 1 day and 7 days, respectively. The most common
indication for anticoagulation was deep vein thrombosis. The primary
composite outcome occurred in 3 patients (4.6%) in the early cohort and 2
patients (12.5%) in the late cohort (p = 0.255). The secondary composite
outcome occurred in 10 patients (15.4%) in the early cohort and 7 patients
(43.8%) in the late cohort (p = 0.034). There were no statistical
differences in any individual components of the composite outcomes, although
recurrent AIS and mortality had numerically higher incidence in the late
cohort.

In this retrospective study, early anticoagulation was not associated
with increased major bleeding risk, but late anticoagulation was associated
with an increased composite risk of major bleeding, thrombotic events, and
all-cause mortality, driven by increases in recurrent AIS and mortality.
Further studies are warranted to expound on the optimal timing of
anticoagulation in this patient population.