Long-term outcome of endovascular treatment versus medical care for carotid artery stenosis in patients not suitable for surgery and randomised in the Carotid and Vertebral Artery Transluminal Angioplasty study (CAVATAS)

BACKGROUND: Optimal treatment of carotid stenosis in patients not suitable for surgery is unclear. The Carotid and Vertebral Artery Transluminal Angioplasty study contained a trial comparing medical and endovascular treatment in patients not suitable for surgery.

METHODS: Forty patients were randomised to medical or endovascular treatment in equal numbers, and patients were followed up for up to 10 years. The primary outcome measure was defined as stroke or death during follow-up, analysed by intention-to-treat. Secondary analyses included disabling stroke, death, any stroke, any stroke or transient ischemic attack (TIA), all during follow-up.

FINDINGS: Baseline characteristics were similar. The risk of stroke, retinal infarction or death within 30 days of endovascular treatment was 5% (95% CI: 0.1-24.9%). By the study end, >50% of patients had suffered a recurrent TIA, stroke or died. One third of events were non-stroke deaths. Overall, there was no significant difference between medical and endovascular treatment in the primary outcome rate of stroke or death after randomisation (hazard ratio: 0.98, 95% CI: 0.39-2.48) or the rate of any stroke or TIA (hazard ratio: 1.43, 95% CI: 0.54-3.75).

INTERPRETATION: We failed to show superiority of endovascular treatment above medical care alone for carotid stenosis in a very small group of patients not suitable for surgical treatment. However, the trial randomised only 40 patients, and was therefore severely underpowered to detect clinically relevant treatment differences. Ongoing trials of carotid stenting will need to demonstrate improved safety and efficacy before endovascular treatment should enter routine practice.