Immediate and Delayed Procedural Stroke or Death in Stenting Versus Endarterectomy for Symptomatic Carotid Stenosis

Abstract

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://ichgcp.net/clinical-trials-registry/NCT00190398" title="See in ClinicalTrials.gov">NCT00190398. URL: http://www.isrctn.com . Unique identifier: ISRCTN57874028. URL: http://www.isrctn.com . Unique identifier: ISRCTN25337470. URL: https://ichgcp.net/clinical-trials-registry/NCT00004732" title="See in ClinicalTrials.gov">NCT00004732.

Keywords: carotid stenosis; endarterectomy; risk; stents; stroke.

Conflict of interest statement

Disclosures

LHB has received an unrestricted research grant from AstraZeneca, as well as consultancy and advisory board fees from Amgen, Bayer, Bristol-Myers Squibb, and Claret Medical. PR has received lecture fees and advisory board fees from Bayer, Boehringer Ingelheim, Bristol-Myers Squibb, Covidien, and Pfizer. OJ received speaker fees from Medtronic, Stryker and Philips. All other authors declare no competing interests.

Figures

Figure 1 –. flow chart.

Study flow chart depicting all patients in the source trials included in this meta-analysis as well as events that precluded them from analysis.

Figure 2 –. Kaplan-Meier curve.

Kaplan-Meier curve of the cumulative incidence of periprocedural stroke or death within 30 days after treatment in the stenting and endarterectomy group seperately. Number of events: 169 events in the CAS group, 88 events in the CEA group. The cumulative incidence of stroke or death was 7.3% in the CAS group and 3.9% in the CEA group.

Figure 3 –. Effects of baseline variables on the risk of stroke or death in patients treated with carotid artery stenting.

Forest plot showing the odds ratios for the effects of the three baseline variables “patient age”, any “history of smoking”, and “qualifying event severity” on the incidence of stroke or death on the day of treatment (day 0), between day 1 and 30, or within 30 days in patients treated with stenting. ORs were estimated by three separate GLMMs (one for the day of treatment, one for day 1–30, and one for the full procedural period), each containing age, any history of smoking, and QE severity (stroke > TIA > ocular ischemia). CI=Confidence Interval; OR=Odds Ratio; QE=Qualifying event; GLMM=general linear mixed model.

Figure 4 –. Effects of baseline variables on the risk of stroke or death in patients treated with carotid endarterectomy.

Forest plot showing the odds ratios for the effects of the baseline variable “mRS at baseline”, and “history of hypertension” on the incidence of stroke or death on the day of treatment (day 0), between day 1 and 30, or within 30 days in patients treated with endarterectomy. ORs were estimated by three separate GLMMs (one for the day of treatment, one for day 1–30, and one for the full procedural period). OR=Odds ratio; CI=confidence interval; GLMM=general linear mixed model; mRS=modified Rankin Scale