May 4, 2022

Study Evaluates Effect of Stenosis Severity on Perioperative Neurologic Events in Symptomatic Carotid Disease

May 4, 2022—In a retrospective analysis of patients undergoing carotid revascularization for symptomatic disease, Garg and colleagues found that severity of stenosis appeared to influence incidence of perioperative neurologic events in patients who underwent carotid endarterectomy (CEA) and transcervical carotid artery revascularization (TCAR) but not transfemoral carotid artery stenting (TFCAS). However, patients with severe stenosis who underwent CEA alone had a lower composite endpoint of stroke/death/myocardial infarction (MI), and a subgroup analysis of CEA patients found a higher incidence of perioperative neurologic events versus those with nonsevere stenosis. The results were published online in Journal of Vascular Surgery.

KEY FINDINGS

In patients who underwent CEA and TCAR, severe stenosis was associated with a lower rate of perioperative neurologic events; this was not observed in the TFCAS cohort.
The composite endpoint of stroke/death/MI was lower for patients with severe stenosis who underwent CEA alone.
In a subgroup analysis, CEA patients with nonsevere stenosis had a higher incidence of perioperative neurologic events versus those with severe stenosis.

Investigators used the Society for Vascular Surgery Vascular Quality Initiative database to prospectively collect data on patient demographics, procedural characteristics, and clinical outcomes on symptomatic patients who had undergone TFCAS, CEA, or TCAR between 2003 and 2020. Patients were stratified by stenosis severity as severe (> 70% stenosis) and nonsevere (< 50% and 50%-69% stenosis), as determined by duplex ultrasound and CTA findings. For TCAR and TFCAS, symptomatic status was determined by the procedure indication, and for CEA, it was defined as an ipsilateral cortical or eye symptom with surgery performed within 180 days.

The primary outcome was postprocedural neurologic events, defined as any new neurologic event before discharge but after the procedure, inclusive of both transient ischemic attack (TIA) and stroke. Secondary outcomes included postoperative mortality (death that occurred during hospitalization), postoperative MI, and a composite endpoint of stroke/death and stroke/death/MI.

The chi-square or Fischer exact test was used to compare categorical variables, and continuous variables were compared using the t test. Multivariate logistic regression was used to assess independent predictors for postoperative events during the index hospitalization. The C statistic was used to validate multivariable models.

Of 29,614 patients, 11,506 (55.6%) underwent CEA, 5,296 (17.9%) underwent TCAR, and 7,811 (26.5%) underwent TFCAS. In the CEA group, those with severe stenosis had a significantly reduced incidence of TIA (0.7% vs 1.0%; P < .02), TIA/stroke (2.6% vs 3.2%; P = .02), stroke/death 1.9% vs 2.3%; P = .02), and stroke/death/MI (2.6% vs 3.2%; P = .036) as compared with nonsevere stenosis. In the TCAR group, the incidence of stroke/TIA was significantly reduced as compared with those with nonsevere stenosis (3% vs 4.3%; P = .03), and all other outcomes were similar between groups. There were no significant differences in any of the outcome measures between those with severe and more moderate stenosis in the TFCAS group.

Multivariable analysis of patients in the CEA group showed that coronary artery disease was associated with postoperative neurologic events (odds ratio [OR], 1.37; 95% CI, 1.04-1.79; P = .02). Severe (vs nonsevere) stenosis (OR, 0.75; 95% CI, 0.6-0.92; P = .007) and white race (OR, 0.69; 95% CI, 0.51-0.92; P = .01) were associated with a reduced rate of postoperative neurologic events. A subgroup analysis of severe versus nonsevere stenosis demonstrated an association of decreased neurologic events for the severe stenosis group.

In the TCAR group, the use of a P2Y12 inhibitor (OR, 0.88; 95% CI, 0.81-0.95; P = .002) and severe (vs nonsevere) stenosis (OR, 0.83; 95% CI, 0.69-0.99; P < .04) were independently associated with a reduced rate of periprocedural neurologic events. In the TFCAS group, age < 70 years (OR, 2.13; 95% CI, 1.61-2.82; P < .001) and hypertension (OR, 1.21; 95% CI, 1.03-1.43; P = .02) were associated with postoperative neurologic events, and degree of stenosis did not appear to be independently associated with the rate of periprocedural stroke or TIA.

The varying outcomes among the study cohorts suggest that perioperative neurologic events are influenced by distinct mechanisms related to technique and stenosis severity that warrant further study, noted the investigators.

ENDOVASCULAR TODAY ASKS…

We asked lead investigator, Karan Garg, MD, with NYU Langone Medical Center in New York, New York, about the study’s findings and what’s next.

How might these findings be applied in real-world settings?

Our findings can better guide physicians in counseling patients with symptomatic carotid disease. Furthermore, this raises awareness that symptomatic patients presenting with nonsevere stenosis have a greater risk of perioperative complications.

Based on the varied findings across each treatment group and endpoint, do you think technical adjustments within each procedure might improve periprocedural events and outcomes, or are the benefits and shortfalls specific to the mechanistic approaches?

Our findings shed some insight into potential mechanisms of perioperative neurologic events in patients with carotid disease undergoing revascularization via the different approaches. Although surgeons use meticulous technique and individualize the approach when treating patients with carotid disease, there are clearly factors beyond our current understanding that influence perioperative complications, for instance plaque morphology or stroke severity.

The authors conclude by raising the question of how plaque morphology and brain physiology might explain the effects of stenosis severity on outcomes. What might future study of these mechanisms look like? Can modern imaging and assessment technologies yield further information?

We believe that plaque morphology and identifying high-risk plaques are crucial for appropriate patient selection, particularly for asymptomatic patients. With better imaging modalities, additional research needs to be directed to understand why some plaques progress to symptoms and others remain asymptomatic. Regarding brain physiology, there may be flow dynamics that play a role depending on stenosis severity, and this also warrants further investigation.

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