Stroke: occult stroke is a risk factor for stroke recurrence in patients with atrial fibrillation

The study aimed to assess occult stroke (CBI), which is often encountered in the diagnosis of acute ischemic stroke, as a risk factor
for stroke recurrence in patients with atrial fibrillation (AF).

In this prospective cohort study, from patients with acute ischemic stroke hospitalized in 14 centers between 2017 and 2019, researchers recruited patients with atrial fibrillation who had no history of stroke or transient ischemic attack and divided them into CBI (+) and CBI(-) groups
.
Regarding the one-year cumulative incidence of recurrent ischaemic stroke and all-cause death, the two groups were compared
using the Fine and Gray subdistributed hazard model and the Cox frailty model with non-stroke death as a competitive risk, respectively.
Each CBI lesion is also classified as embolic (EA) or non-EA CBI
.
The adjusted hazard ratio and 95% CI
for any CBI, EA-only CBI, non-EA-only CBI, and both CBIs were estimated.

Results Of the 1383 patients with initial stroke with atrial fibrillation, 578 patients (41.
8%) had CBI
.
Among the 578 patients with CBIs, 61.
8% (n=357), 21.
8% (n=126), and 16.
4% (n=95)
of EA-only CBIs, non-EA-only CBIs, and two CBIs, respectively.
In the CBI(+) and CBI(-) groups, the estimated 1-year cumulative incidence of recurrent ischemic stroke was 5.
2% and 1.
9%, respectively (tested by Gray, P=0.
001).

CBI increased the risk of recurrent ischaemic stroke (HR = 2.
91 [1.
44 to 5.
88]), but did not increase the risk of all-cause mortality (1.
32 [0.
97 to 1.
80]).

Both EA-only CBIs and both CBIs increased the risk of recurrent ischemic stroke (2.
76 [1.
32-5.
77] and 5.
39 [2.
25-12.
91], respectively), while non-EA-only CBIs did not (1.
44 [0.
40-5.
16]).

The study suggests that people with atrial fibrillation with CBI may have an increased risk of
recurrent stroke.
CBI
may be considered when estimating stroke risk in patients with atrial fibrillation.

References:

Covert Brain Infarction as a Risk Factor for Stroke Recurrence in Patients With Atrial Fibrillation