CASCOM Study: CAR Score Predicting Restroke in Symptomatic Carotid Stenosis With Only Intensive Medical Therapy

Carotid endarterectomy for symptomatic carotid stenosis is based on decades-old trials, while modern medical therapy has substantially improved outcomes. The carotid artery risk (CAR) score predicts stroke risk using clinical and imaging factors. This study evaluates the 2-year risk of recurrent ipsilateral stroke in patients with recent transient ischemic attack, amaurosis fugax, or minor stroke and ipsilateral symptomatic carotid stenosis treated with intensive medical therapy.

In this prospective, single-arm observational study conducted in Denmark from October 2020 to March 2023, we enrolled 109 patients with recent TIA, amaurosis fugax, or minor stroke and 50% to 99% ipsilateral symptomatic carotid stenosis. Patients with a CAR score ≤20% or >20%, as well as those with contraindications to surgery, were included. All received intensive medical therapy. The primary outcome was ipsilateral recurrent stroke or death within 2 years.

The mean age was 73 years; 60% were male patients. Six patients (5.5%) experienced ipsilateral recurrent stroke, representing a ≈75% reduction compared with historical NASCET (North American Symptomatic Carotid Endarterectomy Trial) rates (≈23%). Patients with CAR score ≤20% (n=96) had a significantly lower 2-year stroke rate (3.1%) than those with CAR score >20% (n=13; 23%; P=0.02). The CAR score ≤20% subgroup showed high predictive accuracy: sensitivity of 0.90, specificity of 0.50, and positive predictive value of 0.97.

In this observational study, modern medical therapy was associated with low rates of recurrent stroke in patients with symptomatic carotid stenosis. Patients with a CAR score ≤20% had a very low risk of recurrent stroke, suggesting that selected patients may be managed conservatively.