Risk of Disease Progression in Patients with Moderate Asymptomatic Carotid Artery Stenosis: Implications of Tobacco Use and Dual Antiplatelet Therapy

Why selective screening for asymptomatic carotid stenosis is currently appropriate: a special report

INTRODUCTION

Two of the main reasons recent guidelines do not recommend routine population-wide screening programs for asymptomatic carotid artery stenosis (AsxCS) is that screening could lead to an increase of carotid revascularization procedures and that such mass screening programs may not be cost-effective. Nevertheless, selective screening for AsxCS could have several benefits. This article presents the rationale for such a program.

AREAS COVERED

The benefits of selective screening for AsxCS include early recognition of AsxCS allowing timely initiation of preventive measures to reduce future myocardial infarction (MI), stroke, cardiac death and cardiovascular (CV) event rates.

EXPERT OPINION

Mass screening programs for AsxCS are neither clinically effective nor cost-effective. Nevertheless, targeted screening of populations at high risk for AsxCS provides an opportunity to identify these individuals earlier rather than later and to initiate a number of lifestyle measures, risk factor modifications, and intensive medical therapy in order to prevent future strokes and CV events. For patients at 'higher risk of stroke' on best medical treatment, a prophylactic carotid intervention may be considered.

Asymptomatic Females Are at Higher Risk for Perioperative TIA/Stroke and Males Are at Higher Risk for Long-Term Mortality after Carotid Artery Stenting: A Vascular Quality Initiative Analysis

The study aims to review the sex differences with respect to transient ischemic attack (TIA)/stroke and death in the perioperative period and on long-term follow-up among asymptomatic patients treated with carotid stenting (CAS) in the vascular quality initiative (VQI). All cases reported to VQI of asymptomatic CAS (ACAS) patients were reviewed. The primary end point was risk of TIA/stroke and death in the in-hospital perioperative period and in the long-term follow-up. The secondary end point was to evaluate predictors of in-hospital perioperative TIA/stroke and mortality on long-term follow-up after CAS. There were 22,079 CAS procedures captured from January 2005 to April 2019. There were 5,785 (62.7%) patients in the ACAS group. The rate of in-hospital TIA/stroke was higher in female patients (2.7 vs. 1.87%, p  = 0.005) and the rate of death was not significant (0.03 vs. 0.07%, p  = 0.66). On multivariable logistic regression analysis, prior/current smoking history (odds ratio = 0.58 [95% confidence interval or CI = 0.39-0.87]; p  = 0.008) is a predictor of in-hospital TIA/stroke in females. The long-term all-cause mortality is significantly higher in male patients (26.9 vs. 15.7%, p  < 0.001). On multivariable Cox-regression analysis, prior/current smoking history (hazard ratio or HR = 1.17 [95% CI = 1.01-1.34]; p  = 0.03), coronary artery disease or CAD (HR = 1.15 [95% CI = 1.03-1.28]; p  = 0.009), chronic obstructive pulmonary disease or COPD (HR = 1.73 [95% CI = 1.55-1.93]; p  < 0.001), threat to life American Society of Anesthesiologists (ASA) class (HR = 2.3 [95% CI = 1.43-3.70]; p  = 0.0006), moribund ASA class (HR = 5.66 [95% CI = 2.24-14.29]; p  = 0.0003), and low hemoglobin levels (HR = 0.84 [95% CI = 0.82-0.86]; p  < 0.001) are the predictors of long-term mortality. In asymptomatic carotid disease patients, women had higher rates of in-hospital perioperative TIA/stroke and a predictor of TIA/stroke is a prior/current history of smoking. Meanwhile, long-term all-cause mortality is higher for male patients compared with their female counterparts. Predictors of long-term mortality are prior/current smoking history, CAD, COPD, higher ASA classification of physical status, and low hemoglobin level. These data should be considered prior to offering CAS to asymptomatic female and male patients and careful risks versus benefits discussion should be offered to each individual patient.

Primary mechanism of stroke reduction in transcarotid artery revascularization is dynamic flow reversal

OBJECTIVE

Recent studies have suggested that the low risk of stroke and death associated with transcarotid artery revascularization (TCAR) is partially attributable to a robust dynamic flow reversal system and the avoidance of the atherosclerotic aortic arch during stenting. However, the benefits of flow reversal compared with distal embolic protection (DEP) in reducing stroke or death in TCAR have not been studied.

METHODS

All patients undergoing carotid artery stenting (CAS) via the transcarotid route with either dynamic flow reversal (TCAR) or DEP (TCAS-DEP) in the Vascular Quality Initiative from September 2016 to November 2019 were analyzed. Both multivariable logistic regression and nearest neighbor propensity score-matched analysis were performed to explore the differences in outcomes between the two procedures. The primary outcome was in-hospital stroke or death. The secondary outcomes were stroke, death, myocardial infarction (MI), and the composite of stroke, death, and MI. A secondary analysis was performed to compare transcarotid stenting with DEP vs transfemoral CAS with DEP to evaluate the effects of crossing the aortic arch.

RESULTS

A total of 8426 patients were identified (TCAS-DEP, n = 287; 3.4%). TCAR was associated with a lower risk of in-hospital stroke or death (1.6% vs 5.2%; odds ratio [OR], 0.35; 95% confidence interval [CI], 0.20-0.64; P = .001), stroke (1.4% vs 4.2%; OR, 0.37; 95% CI, 0.20-0.68; P = .002), and stroke/death/MI (2.0% vs 5.2%; OR, 0.41; 95% CI, 0.23-0.71; P = .001) compared with TCAS-DEP. Among the 274 pairs of patients identified with propensity score matching, TCAR was associated with a lower risk of stroke/death (1.1% vs 4.7%; risk ratio [RR], 0.23; 95% CI, 0.06-0.81; P = .021) and stroke (0.4% vs 4.0%; RR, 0.09; 95% CI, 0.01-0.70; P = .006) compared with TCAS-DEP but no differences in stroke/death/MI (1.8% vs 4.7%; RR, 0.38; 95% CI, 0.15-1.02; P = .077). The secondary analysis found no differences in stroke between TCAS-DEP and transfemoral CAS with DEP (4.9% vs 3.7%; RR, 1.3; 95% CI, 0.36-1.63; P = .65).

CONCLUSIONS

Compared with TCAS-DEP, TCAR was associated with a lower risk of perioperative stroke or death and stroke. This finding implies that dynamic flow reversal might provide better neuroprotection than does a distal embolic filter in reducing the perioperative risk of stroke. Avoiding the aortic arch did not confer any reduction in the stroke rate. The present findings serve to separate the clinical benefit of dynamic flow reversal from that of avoiding the aortic arch during TCAR.

Molecular and Nonmolecular Magnetic Resonance Coronary and Carotid Imaging

Atherosclerosis is the leading cause of cardiovascular morbidity and mortality. Over the past 2 decades, increasing research attention is converging on the early detection and monitoring of atherosclerotic plaque. Among several invasive and noninvasive imaging modalities, magnetic resonance imaging (MRI) is emerging as a promising option. Advantages include its versatility, excellent soft tissue contrast for plaque characterization and lack of ionizing radiation. In this review, we will explore the recent advances in multicontrast and multiparametric imaging sequences that are bringing the aspiration of simultaneous arterial lumen, vessel wall, and plaque characterization closer to clinical feasibility. We also discuss the latest advances in molecular magnetic resonance and multimodal atherosclerosis imaging.

Long-Term Outcomes of Carotid Endarterectomy and Carotid Artery Stenting When Performed by a Single Vascular Surgeon

OBJECTIVES:

Carotid artery endarterectomy (CEA) and carotid artery stenting (CAS) are 2 effective treatment options for carotid revascularization and stroke prevention. The long-term outcomes of Carotid Revascularization Endarterectomy versus Stenting Trial (CREST) reported similar stroke and death rate between the 2 procedures. This study presents the short- and long-term outcomes of CEA and CAS of all risk patients performed by a single vascular surgeon in a real-world setting.

METHODS:

We retrospectively reviewed all patients who underwent CEA and CAS from September 2005 to June 2017 at our institute. Student t test, χ², and Fisher exact tests were used to compare patient's characteristics. Multivariate logistic, cox regression models and survival analysis were used to compare postoperative and long-term outcomes between the 2 groups.

RESULTS:

Over 2000 patients were evaluated for carotid artery stenosis during the study period, and 313 revascularization procedures were performed (CEA: 47%, CAS: 53%). Patients' age (Mean [95% confidence interval, CI] 68.8 [67.2-70.4] vs 69.7 [68.2-71.3], P = .40) was similar between CEA and CAS. Patients who underwent CAS had significantly higher comorbidities (chronic obstructive pulmonary disease [COPD], chronic heart failure [CHF], hyperlipidemia, and prior ipsilateral intervention, all P < .05). No difference was found in 30-day complications after CEA versus CAS including stroke (2.0% vs 1.2%), myocardial infarction (MI; 0.7% vs 1.2%), death (0% vs 1.2%) as well as combined major adverse events (stroke/death/MI; 2.7% vs 3.0%; all P > .05). Overall 7-year survival, stroke-free survival and restenosis-free survival were similar between the 2 groups ( P > .5). Significant predictors of mortality were diabetes (hazard ratio, HR [95% CI]: 2.41 [1.15-5.08]), chronic kidney disease (HR [95% CI]: 4.89 [1.97-12.13]), and COPD (HR [95% CI]: 3.31 [1.43-7.71]; all P values <.05). Statin use was protective with 71% reduction in risk of mortality (HR [95% CI]: 0.29 [0.12-0.67], P = .004).

CONCLUSION:

Our experience showed comparable short- and long-term outcomes of CAS and CEA performed for carotid artery stenosis by vascular surgeon. There was no difference between single institutional long-term outcomes and CREST outcomes following CEA and CAS.

Optimal Treatment for Ruptured Pancreaticoduodenal Artery Aneurysm Caused by Celiac Artery Obstruction Due to Celiac Artery Dissection

A pancreaticoduodenal artery (PDA) aneurysm develops due to increased flow through the pancreaticoduodenal arcade in the setting of celiac or superior mesenteric artery occlusion. Additionally, there is no evidence on the computed tomography scan or angiography images that the dissection process extends to the PDA arcade. Moreover, the optimal treatment protocols for PDA aneurysms with celiac artery obstruction and for celiac artery dissection are controversial. We report 2 cases of ruptured PDA aneurysms caused by celiac artery obstruction due to celiac artery dissection in which the aneurysm was excluded, but celiac artery revascularization was not performed successfully. Our cases indicate that endovascular management for ruptured PDA aneurysms and conservative management for celiac artery obstruction due to celiac artery dissection are feasible as first-line treatment in such cases.

Risk of major adverse cardiovascular events in subjects with asymptomatic mild carotid artery stenosis

This study aimed to test the hypothesis that the risk of major adverse cardiovascular events (MACE) is similar for subjects with asymptomatic mild and moderate carotid artery stenosis (CAS). We enrolled a total of 453 subjects with asymptomatic CAS (30-69%) detected on baseline screening Doppler ultrasound (DUS) examination between January 2008 and December 2010. The follow-up DUS findings and MACE occurrence (fatal or nonfatal myocardial infarction or stroke and all-cause mortality) were compared between subjects with mild (30-49%) and moderate (50-69%) CAS during the 8-year follow-up period. There was no significant difference in the occurrence of MACE between subjects with mild (n = 289) and moderate (n = 164) CAS (13.8% vs. 15.9%, respectively; p = 0.56), although there was a nonsignificant trend toward an increased risk of major ipsilateral stroke in subjects with moderate CAS (1.4% vs. 4.3%; p = 0.06). Multivariate regression analysis indicated that worsening CAS was independently associated with MACE occurrence (hazard ratio [HR], 4.40; 95% confidence interval [CI], 2.65-7.27; p < 0.01), whereas an increased serum high-density lipoprotein cholesterol level was correlated with a decreased risk of MACE (HR, 0.42; 95% CI, 0.23-0.75; p < 0.01). The cumulative risk of MACE in subjects with asymptomatic mild CAS is similar to that in subjects with asymptomatic moderate CAS.

Development of a duplex-derived velocity risk prediction model of disease progression in patients with moderate asymptomatic carotid artery stenosis

OBJECTIVE

Previously, we described risk factors for disease progression in moderate asymptomatic carotid artery stenosis (ASCAS). The aim of the current study was to develop a risk prediction model for disease progression in this group.

METHODS

All patients presenting between January 2005 and May 2012 with moderate (50%-69%) ASCAS, as determined by carotid artery duplex imaging, were included. Cox proportional hazard regression models accounting for measured duplex peak systolic velocity and end-diastolic velocity, and the internal carotid artery (ICA)/common carotid artery (CCA) ratio, with and without previously identified risk factors for progression (age, smoking, dual antiplatelet therapy), were used to develop receiver operating characteristic curves for predicting disease progression.

RESULTS

The study analyzed 282 patients (52% male), aged 71 ± 9 years, with 2.6 ± 0.1 years follow-up and 25% disease progression at a mean time of 2.02 ± 0.18 years. Initial peak systolic velocity, end-diastolic velocity, and the ICA/CCA ratio were all significant independent predictors of progression. Receiver operating characteristic curve analyses suggested that a prediction model based on ICA/CCA ratio alone had optimal prediction efficacy (hazard ratio, 2.01; Harrell's C, 0.74; P < .001). Patients with ICA/CCA >2.5, 3.3, and 3.8 were found to have >10%, >20%, and >30% risk of disease progression over 2 years, respectively. Model sensitivity and specificity for predicting 10% risk of disease progression at 2 years was 80.7% and 64.0%, respectively (positive predictive value, 22.9%; negative predictive value, 96.1%).

CONCLUSIONS

We propose a clinical prediction model for moderate ASCAS disease progression that can be used to risk-stratify patients with >10% risk of progression at 2 years using ICA/CCA ratios. Implementation of this model may be useful for identifying high-risk patients who would benefit from routine carotid disease surveillance follow-up.