Felten, Stefanie von

Background: Historical data suggest that patients with recently symptomatic carotid stenosis are at high risk of early recurrent stroke. Guidelines therefore recommend revascularization within 2 weeks of symptoms. We assessed the risk of stroke or death occurring before revascularization in modern trials of symptomatic carotid stenosis. Methods: We pooled data of all individual patients with symptomatic carotid stenosis randomised to stenting (CAS) or endarterectomy (CEA) in the EVA-3S, SPACE, ICSS and CREST trials. The outcome event (OE) was death or any stroke occurring between randomization and treatment by CAS or CEA, or up to 120 days after randomization among patients not undergoing treatment in this period. Results: 4707 patients were included in the analysis. Median time from qualifying event until randomization was 18 (interquartile range 7-50) days. Median time from randomization until treatment was 6 (2-11) days in the CAS group, and 7 (3-12) days in the CEA group (p<0.001). 31% of patients in the CAS group and 27% in the CEA group underwent revascularization within 14 days of the qualifying event. The OE occurred in 21 patients (CAS: 8, CEA: 13), all within 31 days of randomization (Kaplan Meier estimate: 2.4%, standard error 0.7%; fig.), including 18 non-fatal strokes, 1 fatal stroke, and 2 non-stroke related deaths. In 2 of the patients, the date of the qualifying event was unknown, in 8 patients the OE occurred within 14 days of the qualifying event and in 11 patients >14 days after the qualifying event. All patients with the OE had severe (70-99% degree) stenosis. No other baseline variables predicted the OE. Discussion: Despite the fact that less than a third of patients underwent revascularization within 14 days of the qualifying event, only 2.4% of patients had a recurrent stroke or died before treatment. The risk is lower than expected from historical data, which may reflect advances in medical therapy. Patients at risk are those with severe degree of stenosis.

Background: Over the past decades, stroke risk associated with carotid disease has decreased, reflecting improvements in medical therapy and a more rigorous control of vascular risk factors. It is less clear whether the procedural risk of carotid revascularization has declined over time. Methods: We analyzed temporal changes in procedural risks among 4597 patients with symptomatic carotid stenosis treated with carotid artery stenting (n=2326) or carotid endarterectomy (n=2271) in 4 randomized trials between 2000 and 2008, using generalized linear mixed-effects models with a random intercept for each source trial. Models were additionally adjusted for age and other baseline characteristics predicting treatment risk. The primary outcome event was any procedural stroke or death, occurring during or within 30 days after revascularization. Results: The procedural stroke or death risk decreased significantly over time in all patients (unadjusted odds ratio per year, 0.91; 95% CI, 0.85–0.97; P =0.006). This effect was driven by a decrease in the carotid endarterectomy group (unadjusted odds ratio per year, 0.82; 95% CI, 0.73–0.92; P =0.003), whereas no significant decrease was found after carotid artery stenting (unadjusted odds ratio, 0.96; 95% CI, 0.88–1.04; P =0.33). Carotid endarterectomy patients had a lower procedural stroke or death risk compared with carotid artery stenting patients, and the difference significantly increased over time (interaction P =0.031). After adjustment for baseline characteristics, the results remained essentially the same. Conclusions: The risk of stroke or death associated with carotid endarterectomy for symptomatic carotid stenosis decreased over an 8-year period, independent of clinical predictors of procedural risk. No corresponding reduction in procedural risk was seen in patients treated with stenting. Clinical Trial Registration: URL: https://www.clinicaltrials.gov ; http://www.isrctn.com . Unique identifier: NCT00190398 (EVA-3S), NCT00004732 (CREST), ISRCTN57874028 (SPACE), and ISRCTN25337470 (ICSS).

Background and Purpose— Stenting for symptomatic carotid stenosis (carotid artery stenting [CAS]) carries a higher risk of procedural stroke or death than carotid endarterectomy (CEA). It is unclear whether this extra risk is present both on the day of procedure and within 1 to 30 days thereafter and whether clinical risk factors differ between these periods. Methods— We analyzed the risk of stroke or death occurring on the day of procedure (immediate procedural events) and within 1 to 30 days thereafter (delayed procedural events) in 4597 individual patients with symptomatic carotid stenosis who underwent CAS (n=2326) or CEA (n=2271) in 4 randomized trials. Results— Compared with CEA, patients treated with CAS were at greater risk for immediate procedural events (110 versus 42; 4.7% versus 1.9%; odds ratio, 2.6; 95% CI, 1.9–3.8) but not for delayed procedural events (59 versus 46; 2.5% versus 2.0%; odds ratio, 1.3; 95% CI, 0.9–1.9; interaction P =0.006). In patients treated with CAS, age increased the risk for both immediate and delayed events while qualifying event severity only increased the risk of delayed events. In patients treated with CEA, we found no risk factors for immediate events while a higher level of disability at baseline and known history of hypertension were associated with delayed procedural events. Conclusions— The increased procedural stroke or death risk associated with CAS compared with CEA was caused by an excess of events occurring on the day of procedure. This finding demonstrates the need to enhance the procedural safety of CAS by technical improvements of the procedure and increased operator skill. Higher age increased the risk for both immediate and delayed procedural events in CAS, mechanisms of which remain to be elucidated. Clinical Trial Registration— URL: https://clinicaltrials.gov . Unique identifier: NCT00190398. URL: http://www.isrctn.com . Unique identifier: ISRCTN57874028. URL: http://www.isrctn.com . Unique identifier: ISRCTN25337470. URL: https://clinicaltrials.gov . Unique identifier: NCT00004732.