Incident Infarcts, Stroke, and Small Vessel Disease: What Is the Link?

Incident infarcts occur in one-quarter of patients with a history of stroke and are associated with worse baseline small vessel disease (SVD) scores, according to study findings published in the journal Neurology.

Limited information is available on the effect of stroke on incident infarct and vascular risk.

In a prospective observational study, researchers aimed to determine the frequency, type, and timing of incident infarcts in the year after a stroke and their relation to baseline SVD.

Participants from the Mild Stroke Study 3 with mild ischemic stroke, defined as a modified Rankin scale (mRS) of at least 2, were enrolled in the current analysis. The study population was enriched for lacunar index stroke and the control group included patients with nondisabling cortical stroke. All participants received stroke management services.

Magnetic resonance imaging (MRI) was repeated after initial imaging every 3 to 6 months for 12 months. Incident infarcts were visualized via diffusion-weight imaging or fluid-attenuated inversion recovery (FLAIR). Functional and cognitive statuses were recorded using mRS and Montreal Cognitive Assessment (MoCA).

Demographic data and vascular risk factors, including history of stroke or transient ischemic attack (TIA) before index stroke, comorbidities, and other vascular abnormalities, were collected.

A total of 229 participants (mean age, 65.9; women, 33.6%) were included in the study, of whom 131 (57.2%) had lacunar stroke.

A total of 1021 MRI scans were conducted, with a mean interval between index stroke symptoms and baseline MRI of 51.5 days.

At the 1-year MRI visit, the researchers observed 117 incident infarcts in 57 (24.8%) of patients. The majority of the infarcts (73.5%) were of the small subcortical subtype in 66.6% of the participants.

Incident infarcts were detected at the 1 visit for 39 participants, of which 2 or more than 2 infarcts were detected at a single visit for 19 participants. The first incident infarct was detected at a median of 83 days after index stroke. Small subcortical infarcts were first detected earlier than cortical infarcts (71 vs 235 days).

Multivariable analysis showed that SVD score strongly predicted incident small subcortical infarcts (odds ratio [OR], 2.12; 95% CI, 1.48-3.17; P <.001). In fact, baseline SVD score was the strongest predictor of any incident infarct (OR, 1.87; 95% CI, 1.39-2.58).

Of the 57 patients with incident infarcts, 53 (92.9%) received lipid-lowering treatment, 57 (100%) received antiplatelets or anticoagulants, and 40 (70.1%) received at least 1 antihypertensive medication.

At 1 year, 18 participants (7.8%) had 23 episodes of recurrent clinical stroke/TIA, with the median interval between index stroke and clinical stroke/TIA recurrence being 196 days.

Higher 1-year mRS scores were associated with higher baseline mRS scores (OR, 5.57; 3.52-9.10); however, lower 1-year MoCA scores were associated with lower baseline MoCA, premorbid intelligence, and older age (β, 0.47, 0.07, and -0.06, respectively).

One of the main study limitations was the possibility of missing infarcts that may have occurred between visits.

“This study’s findings support the need for better treatments of lacunar stroke and SVD more generally,” the researchers concluded.