Clopidogrel Versus Ticagrelor for Antiplatelet Therapy in Transcarotid Artery Revascularization (TCAR) in the Society for Vascular Surgery Vascular Quality Initiative

Multi-institutional patterns of clopidogrel response among patients undergoing transcarotid artery revascularization

OBJECTIVE

Current guidelines recommend dual antiplatelet therapy (DAPT) in patients undergoing carotid artery stenting. The most common DAPT regimen is aspirin and clopidogrel, a P2Y12 receptor antagonist; however, the prevalence of clopidogrel resistance (CR) in patients undergoing percutaneous coronary interventions may exceed 60%. Few studies have investigated the prevalence and impact of CR in patients undergoing extracranial carotid artery stenting, particularly transcarotid artery revascularization (TCAR).

METHODS

Consecutive high-risk patients ≥ 18 years who underwent TCAR for high grade (≥70%) and/or symptomatic (≥50%) carotid stenosis with preoperative P2Y12 testing between August 2019 and December 2021 were identified across five institutions. Preoperative platelet reactivity was measured with the VerifyNow P2Y12 Reaction Unit (PRU) Test (Instrumentation Laboratory, Bedford, MA), with CR defined as PRU ≥ 194 and hyper-response as PRU <70. Patients without preoperative P2Y12 testing within 30 days prior to TCAR or those on a non-clopidogrel P2Y12 inhibitor preoperatively were excluded. The primary outcome of interest was prevalence of CR. Secondary outcomes of interest included the incidence of ischemic and hemorrhagic complications.

RESULTS

Of 92 patients identified, the majority were male (59%) and Caucasian (75%) with a mean age of 75 years (±8, range 56-92). Preoperatively, 93% of patients were on aspirin, 100% on clopidogrel, and 13% on therapeutic anticoagulation. At presentation, 36% were symptomatic. The mean preoperative P2Y12 was 156 PRU (±76, range 6-349). In total, 30 (33%) patients met criteria for CR (mean PRU 240 ± 37; range 197-349), and 15 (16%) met criteria for hyper-responder (mean PRU 38 ± 20; range 6-68). There was no significant difference by clopidogrel response phenotype in terms of sex (p = 0.246), race (p = 0.384), or symptomatic presentation (p = 0.956). Postoperatively, the cumulative incidence of stroke and MI was 2.1%, with no statistically significant difference in the incidence of in-hospital stroke (PRU 238, p = 0.489) or MI (PRU 168, p = 1) between clopidogrel phenotypes. Three (3.3%) patients, one CR (PRU 240) and two responders (PRU 119 and PRU 189), experienced postoperative access site hematomas that required no subsequent intervention. No other index hospitalization hemorrhagic complications occurred.

CONCLUSIONS

Using preoperative P2Y12 testing with a threshold PRU ≥ 194 to define CR, we identified a high prevalence of CR in patients undergoing TCAR similar to that in the pre-existing coronary literature. We found no significant differences in postoperative ischemic or hemorrhagic complications by clopidogrel response phenotype, although complication rates in the overall study cohort were low. CR may be a spectrum from responder to partial responder to complete non-responder, and this may account for the differences in our CR cohort compared to the ROADSTER 2 protocol deviation cohort. Further investigation is warranted to determine if a quantitative assessment of CR is sufficient to identify patients at risk of developing secondary cerebrovascular ischemic events in this patient population.

Rescue of immediate post-transcarotid artery revascularization carotid stent thrombosis due to clopidogrel resistance using flow-reversal and aspiration thrombectomy

An 84-year-old patient developed immediate thrombosis of his carotid stent in recovery after transcarotid artery revascularization. In the present report, the technical details about intraoperative management for neurovascular rescue using the transcarotid artery revascularization flow-reversal system are described. The patient was determined to have clopidogrel resistance. Intraoperative medical management is also discussed. The current alternative intravenous and oral antiplatelet therapies such as glycoprotein IIb/IIIa and P2Y12 inhibitors are explored. The debate regarding preoperative antiplatelet resistance testing remains ambiguous, and increasing studies have demonstrated the safety and efficacy of alternatives to clopidogrel. Despite an unpredictable and devastating complication, the patient's outcome was successful using contemporary strategies.

Safety of Transcarotid Revascularization in Patients with a Contraindication to Dual Antiplatelets

OBJECTIVE

Current carotid artery stenting practice guidelines recommend dual antiplatelets to reduce major adverse cardiovascular events during and after transcarotid revascularization (TCAR). However, some patients are poor candidates for this regimen, due to preexisting need for anticoagulation, allergies, and/or risk of major bleeding. Therefore, this investigation was performed to review outcomes associated with patients undergoing TCAR while on alternative medication regimens to determine safety and efficacy.

METHODS

A retrospective review was performed of a combined database created by the combination of institutional carotid revascularization archives maintained at 2 high-volume TCAR health systems. Patients taking dual antiplatelets were compared to those on nontraditional medications with respect to demographics and perioperative and long-term outcomes.

RESULTS

Between our 2 member institutions, 729 TCAR procedures, consisting of 549 patients on dual antiplatelets and 180 on alternative treatments, qualified for study inclusion and analyzed. The cohort not taking dual antiplatelets presented with a heavier comorbidity burden by Charlson Comorbidity Index (5.3 ± 2.2 vs 6.1 ± 2.2, P < .01). Additionally, these patients underwent higher risk revascularization procedures, as they had a higher proportion of symptomatic lesions (34.6% vs 43.0%, P = .03). Despite these deviations in baseline characteristics, similar outcomes between groups were observed in the 30-day perioperative period with respect to stroke (2.2% vs 2.8%, P = .58), death (1.3% vs 1.1%, P > .99), and myocardial infarction (.4% vs 0%, P > .99). Similarly, rates of reintervention (1.6% vs 1.1%, P > .99), hematoma formation (2.4% vs 2.2%, P > .99), and stent thrombosis (.5% vs .6%, P > .99) were consistent, regardless of antiplatelet status. At follow-up of 25.4 and 29.1 months, respectively, for the dual antiplatelet and alternative treatment cohorts, no deviations with respect to reintervention, stroke, myocardial infarction, or stent thrombosis were noted. However, there was an increased risk of death (5.4% vs 13.5%, P = .02) in the alternative regimen group.

CONCLUSION

In this small series of TCARs, patients not maintained on dual antiplatelets did not experience more perioperative adverse events after TCAR. However, more studies, in larger series, are required to verify and validate these findings.