An evidence-based review of the impact of periprocedural myocardial infarction in carotid revascularization

One swallow does not a summer make but many swallows do: accumulating clinical evidence for nearly-eliminated peri-procedural and 30-day complications with mesh-covered stents transforms the carotid revascularisation field

Atherosclerotic carotid artery stenosis (CS) continues to be a common cause of acute ischaemic stroke. Optimised medical therapy (OMT), the first-line treatment modality in CS, may reduce or delay - but it does not abolish - CS-related strokes. As per current AHA/ASA and ESC/ESVS/ESO guidelines, carotid artery stenting (CAS) is a less-invasive alternative to carotid endarterectomy (CEA) for CS revascularisation in primary and secondary stroke prevention. Ten-year follow-up from the CREST trial in patients with symptomatic and asymptomatic CS confirmed equipoise of CAS and CEA in the primary endpoint. Nevertheless CAS - using a widely open-cell, first-generation stent and first-generation (distal/filter) neuroprotection - has been criticised for its relative excess of (mostly minor) strokes by 30 days, a significant proportion of which were post-procedural. Atherosclerotic plaque protrusion through conventional carotid stent struts, confirmed on intravascular imaging, has been implicated as a leading mechanism of the relative excess of strokes with CAS vs. CEA, including delayed strokes with CAS. Different designs of mesh-covered carotid stents have been developed to prevent plaque prolapse. Several multi-centre/multi-specialty clinical studies with CGurad MicroNet-Covered Embolic Prevention Stent System (EPS) and RoadSaver/Casper were recently published and included routine DW-MRI cerebral imaging peri-procedurally and at 30 days (CGuard EPS). Data from more than 550 patients in mesh-covered carotid stent clinical studies to-date show an overall 30-day complication rate of ~1% with near-elimination of post-procedural events. While more (and long-term) evidence is still anticipated, these results - taken together with optimised intra-procedural neuroprotection in CAS (increased use of proximal systems including trans-carotid dynamic flow reversal) and the positive 12-month mesh-covered stent data reports in 2017 - are transforming the carotid revascularisation field today. Establishing effective algorithms to identify the asymptomatic subjects at stroke risk despite OMT, and large-scale studies with mesh-covered stents including long-term clinical and duplex ultrasound outcomes, are the next major goals.

Carotid stenting versus endarterectomy for the treatment of carotid artery stenosis: Contemporary results from a large single center study

OBJECTIVE

To compare the complication rates associated with carotid endarterectomy (CEA) versus carotid artery stenting (CAS).

BACKGROUND

Carotid stenosis is a well-known cause of stroke and increased mortality. The safety of carotid revascularization may be related to symptom status, medical comorbidities, use of embolic protection devices, as well as operator experience and these factors may vary across patient populations within a single operating center.

METHODS

We retrospectively analyzed patients with carotid artery stenosis admitted to our hospital for carotid revascularization between January 1, 2007 and December 1, 2013. The primary end point was a composite endpoint of periprocedural death, stroke, and myocardial infarction (MI).

RESULTS

Of the 718 patients admitted for carotid revascularization 525 (73.1%) underwent CEA and 193 (26.9%) underwent CAS. Both groups demonstrated similar rates of the composite endpoint, MI, and death; the stenting group demonstrated a higher rate of stroke (4.2% vs. 1.3%; P = 0.020). Adjusting for baseline medical comorbidities and symptom status mitigated this difference (P = 0.091 and 0.113, respectively). When stratified by department performing CAS, there was a significant difference in the occurrence of stroke (P = 0.033), which likewise disappeared in the multivariate regression analysis.

CONCLUSION

The risk of the composite endpoint did not differ significantly between those undergoing CAS versus CEA. The stenting group demonstrated a higher rate of periprocedural stroke, which was also apparent when patients were stratified by stenting department. These differences were likely driven by variation in baseline medical comorbidities and symptom status. © 2016 Wiley Periodicals, Inc.

Anesthetic type and risk of myocardial infarction after carotid endarterectomy in the Carotid Revascularization Endarterectomy versus Stenting Trial (CREST)

OBJECTIVE

Carotid endarterectomy (CEA) is usually performed under general anesthesia (GA), although some advocate regional anesthesia (RA) to reduce hemodynamic instability and allow neurologic monitoring and selective shunting. RA does not reduce risk of periprocedural stroke or death, although some series show a reduction in myocardial infarction (MI). We investigated the association of anesthesia type and periprocedural MI among patients receiving GA or RA for CEA and patients undergoing carotid artery stenting (CAS) in the Carotid Revascularization Endarterectomy versus Stenting Trial (CREST).

METHODS

Between 2000 and 2008, 1151 patients underwent CEA (anesthetic type available for 1149 patients), and 1123 patients underwent CAS ≤30 days of randomization in CREST. CEA patients were categorized by anesthetic type (GA vs RA). CREST defined protocol MI as chest pain or electrocardiogram change plus biomarker evidence of MI, and total MI was defined as protocol MI plus biomarker-positive (+)-only MI. The incidence of protocol MI and total MI in patients undergoing CEA under GA and RA were compared with those undergoing CAS. Other study end points were similarly compared. Differences in baseline characteristics and periprocedural events were evaluated among the three groups. Logistic regression, adjusting for age and symptomatic status, was used to assess group differences.

RESULTS

The three groups had similar demographic risk factors, except for prevalence of symptomatic carotid stenosis, which was lowest in the CEA-RA group (P = .03). Of the 111 patients in the CEA-RA group, no protocol MIs occurred and only two biomarker+-only MIs, for an overall incidence of 1.8%, similar to the 1.7% overall incidence in patients undergoing CAS. In contrast, the combined incidence of protocol and biomarker+-only MIs in the 1038 patients in the CEA-GA group was significantly higher at 3.4% (P = .04), twice the risk of protocol MI and biomarker+-only MI compared with those undergoing CAS (odds ratio [OR], 2.01; 95% confidence interval [CI], 1.14-3.54). Direct comparison of the MI incidence between CEA-RA and CEA-GA showed no statistical difference. Patients undergoing CEA-GA had lower odds of a periprocedural stroke (OR, 0.48; 95% CI, 0.28-0.79) and stroke or death (OR, 0.46; 95% CI, 0.27-0.76) compared with those undergoing CAS but were not significantly different from those undergoing CEA-RA.

CONCLUSIONS

Patients in CREST undergoing CEA-RA had a similar risk of periprocedural MI as those undergoing CAS, whereas the risk for CEA-GA was twice that compared with patients undergoing CAS. Nevertheless, because periprocedural MI is one of the few variables favoring CAS over CEA and has been associated with decreased long-term survival, RA should be seriously considered for patients undergoing CEA.

Surgery Versus Stenting in Symptomatic Patients

Symptomatic carotid artery stenosis is an important cause of stroke with significant morbidity and mortality. Revascularization with carotid endarterectomy reduces the recurrence of stroke and until recently was considered the gold standard of therapy. Carotid artery stenting has emerged as an alternative method of revascularization in both high-risk and standard-risk patients. This review appraises the role of surgery versus stenting for patients with symptomatic carotid stenosis.