TIA, Minor Stroke With Causal Atherosclerosis and Increased Risk of 5-Year Vascular Events

Comorbidity of diseases underlying transient ischemic attack (TIA) or minor ischemic stroke is substantial, with the 5-year rate of major vascular events about 5 times higher in patients with causal atherosclerosis, according to a study in JAMA Neurology.

Researchers evaluated the coexistence between underlying pathology in patients with TIA and minor ischemic stroke, their 5-year risk for major vascular events, and factors associated with risks using the atherosclerosis, small vessel disease, cardiac pathology, other cause, or dissection (ASCOD) classification system.

Data were obtained from TIAregistry.org, an international cohort of patients who had a TIA or minor stroke within 7 days of enrollment between June 1, 2009, and December 31, 2011, and were followed up for 5 years through December 31, 2016. The study was conducted in 61 specialized centers, and the analysis was performed from October 1, 2022, to June 15, 2023.

The primary outcome was a composite of cardiovascular death, nonfatal stroke (ischemic or hemorrhagic), and nonfatal acute coronary syndrome.

A total of 3847 patients (mean age, 66.4 [SD, 13.2] years; 59.7% men) from 42 sites participated in the 5-year follow-up with more than 50% 5-year visits. The median percentage of 5-year follow-up per center was 92.3%, and 3383 patients (87.9%) had a 5-year visit.

Of the cohort, 36.5% of patients had no atherosclerosis (ASCOD A0), 28.8% had atherosclerosis in any vascular beds but no stenosis ipsilateral to the ischemic area which was unlikely causal (ASCOD A3), 25.9% had stenosis ipsilateral to the ischemic area which was possibly or probably causal (ASCOD A1 or A2), and 335 (8.7%) had no assessment of atherosclerosis (ASCOD A9).

Of the participants who had probably or possibly causal atherosclerotic disease, 49.0% had some form of small vessel disease (SVD), including 11.0% for whom a lacunar stroke also was probably or possibly causal, and 50.5% who had no SVD. Also, 27.6% patients had some cardiac findings, including 22.6% for whom a cardiac pathology also was probably or possibly causal, and 70.3% who had no cardiac findings.

The effect size for 5-year major vascular events was about 5.0 times greater among patients who had causal atherosclerosis (HR, 4.86; 95% CI, 3.07-7.72), 2.5 times greater in those with causal lacunar stroke or lacunar syndrome (HR, 2.57; 95% CI, 1.58- 4.20), and 4.0 times higher in patients who had causal cardiac pathology (HR, 4.01; 95% CI, 2.50-6.44).

Limitations of the study include the use of centers from highly specialized TIA clinic and stroke units, with a recruitment bias for patients who sought medical attention. Also, the presence of 5 categories of underlying diseases may not have been complete in many patients, and false-positive findings were not excluded.

“The findings of this cohort study suggest that among patients with TIA or minor ischemic stroke, the coexistence of atherosclerosis, SVD, cardiac pathology, dissection, or other causes is substantial, and the 5-year risk of major vascular events and of stroke outcome vary considerably across the 5 categories of underlying diseases, with atherosclerosis having the highest risk, SVD having an intermediate risk, and no underlying identified causal disease having the lowest risk,” the investigators wrote.

Disclosure: This study was supported by unrestricted grants from AstraZeneca, Sanofi SA, and Bristol Myers Squibb to the SOS Attaque Cérébrale Association. Some of the study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.

This article originally appeared on The Cardiology Advisor