Real-World Outcomes of Carotid Artery Stenting in Symptomatic and Asymptomatic Patients With Carotid Artery Stenosis

The diagnosis and treatment of asymptomatic and symptomatic patients with carotid artery stenosis

Carotid artery atherosclerotic stenosis is an important annual cause of stroke in the United States. Moreover, the incidence of carotid artery stenosis is significantly increasing due to the widespread popularity of high fat and high salt diets, sedentary lifestyles, and the increasing age of the population. Of major importance to cardiovascular specialists is the fact that individuals with atherosclerotic carotid artery stenosis can have a prevalence of atherosclerotic coronary artery disease as high as 50 to 75%. Vascular screening for carotid artery stenosis with Doppler ultrasound should be considered for all symptomatic patients with possible carotid stenosis and also considered for asymptomatic patients with (1) symptomatic peripheral arterial disease, coronary artery disease, or atherosclerotic aortic aneurysm or, (2) multiple atherosclerotic risk factors. Carotid artery atherosclerotic plaques that are at high risk for rupture and thrombosis or cerebral embolization are characterized by large lipid cores, intraplaque hemorrhage, thin fibrous caps less than 165 μms that are infiltrated by macrophages and T cells or have surface ulcer(s) or fissures. Carotid artery plaque rupture with cerebral embolism can cause a stroke, transient ischemic attacks (TIA), or ipsilateral blindness (amaurosis fugax). Medical treatment based on the recommendations of the American and European Societies for Vascular Surgery and the American Heart Association for symptomatic patients with carotid stenosis and also asymptomatic patients with high risk carotid stenosis plaques include antiplatelet drugs, antihypertensive drugs for hypertension control and lipid lowering drugs. Management strategies and decisions about carotid revascularization in asymptomatic patients with high risk carotid stenosis should involve a multidisciplinary team and shared decision-making is recommended. The 30 day and five to 10 year outcomes in asymptomatic carotid stenosis patients who have undergone carotid endarterectomy, carotid stenting and/or optimal medical therapy are summarized from the Veterans Administration Cooperative Study, the Asymptomatic Carotid Atherosclerosis Study and the Asymptomatic Carotid Surgery Trials. The current Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis Trial (CREST-2) should help to resolve the debate regarding carotid artery revascularization versus primary medical treatment in asymptomatic patients with >70% carotid artery stenosis. Symptomatic patients who present within 4.5 hours of stroke onset require evaluation for acute intravenous pharmacologic thrombolysis and patients who present with large vessel occlusion within 24 hours of symptom onset should be considered for mechanical thrombectomy to reduce the neurologic deficit. Patients with carotid artery stenosis who present with a history of cerebral infarct in the preceding six months due to cerebral embolism require medical treatment and evaluation by a multidisciplinary team for carotid revascularization in order to prevent future strokes or TIAs. The outcomes of the North American Symptomatic Carotid Endarterectomy Trial, Carotid Revascularization Endarterectomy Versus Stent Trial, Stent-Supported Percutaneous Angioplasty of the Carotid Artery vs. Endarterectomy Trial, and the Safety and Efficacy Study for Reverse Flow Used during Carotid Artery Stenting Procedure trials for symptomatic patients with carotid stenosis are reviewed. A synopsis of treatment guidelines for symptomatic and asymptomatic carotid stenosis patients from the American and European Societies of Vascular Surgery and the American Heart Association/American Stroke Association are presented. Each patient with carotid artery stenosis must be carefully evaluated to determine the best treatment based on the clinical presentation, the imaging and laboratory diagnostic information, the treatment guidelines, and the patient needs and preferences as well as the patient's social and cultural factors.

Investigation of the hyperperfusion phenomenon following carotid artery stenting using preoperative computed tomography perfusion imaging

PURPOSE

This study aimed to identify the most effective parameters of computed tomography perfusion imaging (CTP) using the Bayesian estimation to predict hyperperfusion phenomenon (HPP) risk after carotid artery stenting (CAS).

METHODS

We retrospectively analyzed 46 patients who underwent CAS with preoperative CTP and preoperative and postoperative 123I-labeled N-isopropyl-p-iodoamphetamine (123I-IMP) single photon emission computed tomography (SPECT) at rest, between April 2019 and March 2024. Patients were categorized into the HPP and non-HPP groups based on the postoperative asymmetry index (AI) of cerebral blood flow (CBF) on 123I-IMP SPECT. Relative ratios of CBF, cerebral blood volume (CBV), mean transit time (MTT), and time-to-peak (TTP) were calculated from preoperative CTP and compared between the two groups. Correlations among each CTP parameter, preoperative AI, and postoperative AI were assessed. Receiver operating characteristic (ROC) analysis identified the most accurate CTP parameters for predicting HPP.

RESULTS

HPP occurred in four patients, with one developing cerebral hemorrhage. Significant differences were observed between the HPP and non-HPP groups in CBV (p = 0.001), MTT (p = 0.003), and TTP ratio (p = 0.011), and preoperative AI (p = 0.021). Among the CTP parameters and preoperative AI, the CBV ratio showed a positive correlation with the postoperative AI (r = 0.63, p < 0.01). The CBV ratio demonstrated the highest area under the curve (AUC) for predicting HPP (AUC = 0.95). However, after Benjamini-Hochberg correction, statistical significance was lost (adjusted p = 0.07).

CONCLUSION

This study evaluated the predictive value of preoperative CTP using the Bayesian estimation method for identifying HPP risk after CAS. CBV ratio may serve as a potential parameter for predicting HPP.

Prediction of cardiovascular events after carotid endarterectomy using pathological images and clinical data

PURPOSE

Carotid endarterectomy (CEA) is a surgical treatment for carotid artery stenosis. After CEA, some patients experience cardiovascular events (myocardial infarction, stroke, etc.); however, the prognostic factor has yet to be revealed. Therefore, this study explores the predictive factors in pathological images and predicts cardiovascular events within one year after CEA using pathological images of carotid plaques and patients' clinical data.

METHOD

This paper proposes a two-step method to predict the prognosis of CEA patients. The proposed method first computes the pathological risk score using an anomaly detection model trained using pathological images of patients without cardiovascular events. By concatenating the obtained image-based risk score with a patient's clinical data, a statistical machine learning-based classifier predicts the patient's prognosis.

RESULTS

We evaluate the proposed method on a dataset containing 120 patients without cardiovascular events and 21 patients with events. The combination of autoencoder as the anomaly detection model and XGBoost as the classification model obtained the best results: area under the receiver operating characteristic curve, accuracy, sensitivity, specificity, and F1-score were 81.9%, 84.1%, 79.1%, 86.3%, and 76.6%, respectively. These values were superior to those obtained using pathological images or clinical data alone.

CONCLUSION

We showed the feasibility of predicting CEA patient's long-term prognosis using pathological images and clinical data. Our results revealed some histopathological features related to cardiovascular events: plaque hemorrhage (thrombus), lymphocytic infiltration, and hemosiderin deposition, which will contribute to developing preventive treatment methods for plaque development and progression.

Sex differences in outcomes of carotid artery stenting

OBJECTIVE

Existing evidence is inconclusive on whether women after carotid artery stenting (CAS) experience worse outcomes than men.

METHODS

The outcomes of women and men were compared using the data from nationwide retrospective registry between 2015 and 2019. The primary outcome was the incidence of ischemic stroke and all-cause death. Secondary outcomes included the incidence of ischemic stroke, all-cause death, acute occlusion, and acute myocardial infarction. Functional outcomes were the achieving an mRS score of 0-1 and 0-2. Outcomes were assessed at 30 days after CAS.

RESULTS

In total, 9792 patients (1330 women, 8862 men; mean age, 73.8 vs 73.5 years, p = 0.17) were analyzed. Symptomatic stenosis was common in men (52.0% vs. 55.1%; p = 0.03), while ≥50% stenosis after CAS was common in women (3.2% vs. 2.0%; p = 0.005). The primary outcome was no significantly difference in women and men (2.0% vs. 1.9%; adjusted odds ratio [aOR], 1.19; 95% confidence interval [95%CI], 0.75-1.88).The incidence of all-cause death was higher in women (0.9% vs. 0.5%; aOR, 2.45; 95%CI, 1.11-5.39). Functional outcomes were significantly less common in women than in men (mRS0-1, 72.6% vs. 74.8%; aOR, 0.77; 95%CI, 0.63-0.95; mRS0-2, 82.1% vs. 85.6%; aOR, 0.76; 95%CI, 0.60-0.95).

CONCLUSIONS

This study suggests that there was no significant sex differences in the incidence of ischemic stroke and all-cause death at 30 days. However, women have higher rate of all-cause death and poorer functional outcomes at 30 days than men.