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

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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 low risk of recurrent stroke, suggesting that selected patients may be managed conservatively.