The impact of carotid lesion calcification on outcomes of carotid artery stenting

The Evolution of Current Management for Carotid Artery Bifurcation Disease

Options for treatment of symptomatic carotid bifurcation disease include carotid endarterectomy (CEA) and carotid artery stenting (CAS). While over the years CEA has established itself as the gold standard for carotid artery revascularization, results from recent trials have shown CAS to be safe and effective in selected patients. This review details the evolution of carotid artery bifurcation disease by highlighting key clinical trials.

"TCAR or nothing": the only options for some complex carotid stenosis

Transcervical carotid artery revascularization has emerged as an alternative to carotid endarterectomy and transfemoral carotid artery stenting. We present four cases for which we believe transcervical carotid artery revascularization was the only option to treat the lesions. Each case presented with specific technical challenges that were overcome by intraoperative planning that allowed for safe deployment of the Enroute stent (Silk Road Medical) with resolution of each patient's stenosis.

Association of stroke or death with severity of carotid lesion calcification in patients undergoing carotid artery stenting

OBJECTIVE

Carotid artery stenting (CAS) for heavily calcified lesions is controversial due to concern for stent failure and increased perioperative stroke risk. However, the degree to which calcification affects outcomes is poorly understood, particularly in transcarotid artery revascularization (TCAR). With the precipitous increase in TCAR use and its expansion to standard surgical-risk patients, we aimed to determine the impact of lesion calcification on CAS outcomes to ensure its safe and appropriate use.

METHODS

We identified patients in the Vascular Quality Initiative who underwent first-time transfemoral CAS (tfCAS) and TCAR between 2016 and 2021. Patients were stratified into groups based on degree of lesion calcification: no calcification, 1% to 50% calcification, 51% to 99% calcification, and 100% circumferential calcification or intraluminal protrusion. Outcomes included in-hospital and 1-year composite stroke/death, as well as individual stroke, death, and myocardial infarction outcomes. Logistic regression was used to evaluate associations between degree of calcification and these outcomes.

RESULTS

Among 21,860 patients undergoing CAS, 28% patients had no calcification, 34% had 1% to 50% calcification, 35% had 51% to 99% calcification, and 3% had 100% circumferential calcification/protrusion. Patients with 51% to 99% and circumferential calcification/protrusion had higher odds of in-hospital stroke/death (odds ratio [OR], 1.3; 95% confidence interval [CI], 1.02-1.6; P = .034; OR, 1.9; 95% CI, 1.1-2.9; P = .004, respectively) compared with those with no calcification. Circumferential calcification was also associated with increased risk for in-hospital myocardial infarction (OR, 3.5; 95% CI, 1.5-8.0; P = .003). In tfCAS patients, only circumferential calcification/protrusion was associated with higher in-hospital stroke/death odds (OR, 2.0; 95% CI, 1.2-3.4; P = .013), whereas for TCAR patients, 51% to 99% calcification was associated with increased odds of in-hospital stroke/death (OR, 1.5; 95% CI, 1.1-2.2; P = .025). At 1 year, circumferential calcification/protrusion was associated with higher odds of ipsilateral stroke/death (12.4% vs 6.6%; hazard ratio, 1.64; P = .002).

CONCLUSIONS

Among patients undergoing CAS, there is an increased risk of in-hospital stroke/death for lesions with >50% calcification or circumferential/protruding plaques. Increasing severity of carotid lesion calcification is a significant risk factor for stroke/death in patients undergoing CAS, regardless of approach.

Modality-specific outcomes of patients undergoing carotid revascularization in the setting of recent myocardial infarction

OBJECTIVE

Recent myocardial infarction (MI) represents a real challenge in patients requiring any vascular procedure. There is currently a lack of data on the effect of preoperative MI on the outcomes of carotid revascularization methodology (carotid enterectomy [CEA], transfemoral carotid artery stenting [TFCAS], or transcarotid artery revascularization [TCAR]). This study looks to identify modality-specific outcomes for patients with recent MI undergoing carotid revascularization.

METHODS

Data was collected from the Vascular Quality Initiative (2016-2022) for patients with carotid stenosis in the United States and Canada with recent MI (<6 months) undergoing CEA, TFCAS, or TCAR. In-hospital outcomes after TFCAS vs CEA and TCAR vs CEA were compared. TCAR vs TFCAS were compared in a secondary analysis. We used logistic regression models to compare the outcomes of these three procedures in patients with recent MI, adjusting for potential confounders. Primary outcomes included 30-day in-hospital rates of stroke, death, and MI. Secondary outcomes included stroke/death, stroke/death/MI, postoperative hypertension, postoperative hypotension, prolonged length of stay (>2 days), and 30-day mortality.

RESULTS

The final cohort included 1217 CEA (54.2%), 445 TFCAS (19.8%), and 584 TCAR (26.0%) cases. Patients undergoing CEA were more likely to have prior coronary artery bypass graft/percutaneous coronary intervention and to use anticoagulant. Patients undergoing TFCAS were more likely to be symptomatic, have prior congestive heart failure, chronic obstructive pulmonary disease, chronic kidney disease, and undergo urgent operations. Patients undergoing TCAR were more likely to have higher rates of American Society of Anesthesiologists class IV to V, P2Y12 inhibitor, and protamine use. In the univariate analysis, CEA was associated with a lower rate of ipsilateral stroke (P = .079), death (P = .002), and 30-day mortality (P = .007). After adjusting for confounders, TFCAS was associated with increased risk of stroke/death (adjusted odds ratio [aOR], 2.69; 95% confidence interval [CI], 1.36-5.35; P = .005) and stroke/death/MI (aOR, 1.67; 95% CI, 1.07-2.60; P = .025) compared with CEA. However, TCAR had similar outcomes compared with CEA. Both TFCAS and TCAR were associated with increased risk of postoperative hypotension (aOR, 1.62; 95% CI, 1.18-2.23; P = .003 and aOR, 1.74; 95% CI, 1.31-2.32; P ≤ .001, respectively) and decreased risk of postoperative hypertension (aOR, 0.59; 95% CI, 0.36-0.95; P = .029 and aOR, 0.50; 95% CI, 0.36-0.71; P ≤ .001, respectively) compared with CEA.

CONCLUSIONS

Although recent MI has been established as a high-risk criterion for CEA and an approved indication for TFCAS, this study showed that CEA is safer in this population with lower risk of stroke/death and stroke/death/MI compared with TFCAS. TCAR had similar stroke/death/MI outcomes in comparison to CEA in patients with recent MI. Further prospective studies are needed to confirm our findings.

Effect of plaque morphological characteristics on the outcomes of carotid artery stenting

Carotid artery stenting (CAS) represents today an accepted option for the treatment of severe carotid artery stenosis. The evolution of materials, techniques, perioperative medical management and patients' selection, has allowed to progressively reduce CAS complications. However, the main drawback of CAS is still represented by the risk of cerebral embolization, that may occur during several steps of the procedure and also in the early postoperative period. Preoperative carotid plaque morphological characteristics may have a great role in determining the risk of embolization during CAS. This review summarizes the current knowledge on carotid plaque characteristics that may influence the risk of complication during CAS. This information may be important for the optimization of CAS patients' selection and adaptation of the materials and techniques.

A Case of Symptomatic Common Carotid Artery Occlusion Treated by a Bridging Bypass Using Short Saphenous Vein Graft

An 86-year-old woman with initially asymptomatic severe right common carotid artery stenosis had frequent transient left hemiparesis 2 years after the initial diagnosis. Magnetic resonance angiography and three-dimensional computed tomography angiography demonstrated short-segment occlusion of the right carotid bifurcation with significant circumferential calcification, while magnetic resonance imaging demonstrated no ischemic lesions. No collateral blood flow through the anterior communicating artery and posterior communicating artery was observed. A bridging bypass from the distal common carotid artery to the proximal cervical internal carotid artery using a saphenous vein graft was made. There were no ischemic symptoms following the procedure. Bridging bypass using the short saphenous vein graft might be useful for short-segment common carotid artery occlusion.

What Is the Role of Transcarotid Artery Revascularization?

Carotid endarterectomy (CEA) is the gold-standard method of carotid revascularization in symptomatic patients with ≥50% and in asymptomatic patients with ≥70% stenosis. Transfemoral carotid artery stenting (TFCAS) has been associated with higher perioperative stroke rates compared to CEA in several studies. On the other hand, transcarotid artery revascularization (TCAR) has outperformed TFCAS in patients who are considered high risk for surgery. There is increasing data that supports TCAR as a safe and efficient technique with outcomes similar to those of CEA, but additional level-one studies are necessary to evaluate the long-term outcomes of TCAR in high- and standard-risk patients.

Interventions in Carotid Artery Surgery: An Overview of Current Management and Future Implications

Atherosclerotic carotid artery disease has been well studied over the last half-century by multiple randomized controlled trials attempting to elucidate the appropriate modality of therapy for this disease process. Surgical techniques have evolved from carotid artery endarterectomy and transfemoral carotid artery stenting to the development of hybrid techniques in transcarotid artery revascularization. In this article, the authors provide a review of the available literature regarding operative and medical management of carotid artery disease.

Impact of calcified plaque volume on technical and 3-year outcomes after transcarotid artery revascularization

OBJECTIVE

We sought to quantify the percent calcification within carotid artery plaques and assess its impact on percent residual stenosis and rate of restenosis in patients undergoing transcarotid artery revascularization for symptomatic and asymptomatic carotid artery stenosis.

METHODS

A retrospective review of prospectively collected institutional Vascular Quality Initiative data was performed to identify all patients undergoing transcarotid artery revascularization from December 2015 to June 2021 (n = 210). Patient and lesion characteristics were extracted. Using a semiautomated workflow, preoperative computed tomography head and neck angiograms were analyzed to determine the calcified plaque volume in distal common carotid artery and internal carotid artery plaques. Intraoperative digital subtraction angiograms were reviewed to calculate the percent residual stenosis post-intervention according to North American Symptomatic Carotid Endarterectomy Trial criteria. Peak systolic velocity and end-diastolic velocity were extracted from outpatient carotid duplex ultrasound examinations. Univariate logistic regression was performed to analyze the relationship of calcium volume percent and Vascular Quality Initiative lesion calcification to percent residual stenosis in completion angiograms. Kaplan-Meier analysis examined the relationship between calcium volume percent and in-stent stenosis over 36 months.

RESULTS

One hundred ninety-seven carotid arteries were preliminarily examined. Predilation was performed in 87.4% of cases with a mean balloon diameter of 5.1 ± 0.7 mm and a mean stent diameter was 8.8 ± 1.1 mm. The mean calcium volume percent was 11.9 ± 12.4% and the mean percent residual stenosis was 16.1 ± 15.6%. Univariate logistic regression demonstrated a statistically significant difference between calcium volume percent and percent residual stenosis (odds ratio [OR], 1.324; 95% confidence interval [CI], 1.005-1.746; P = .046). Stratified by quartile, only the top 25% of calcified plaques (>18.7% calcification) demonstrated a statistically significant association with higher percent residual stenosis (OR, 2.532; 95% CI, 1.049-6.115; P =.039). There was no statistical significance with lesion calcification (OR, 1.298; 95% C,: 0.980-1.718; P = .069). A Kaplan-Meier analysis demonstrated a statistically significant increase in the rate of in-stent stenosis during a 36-month follow-up for lesions containing >8.2% calcium volume (P = .0069).

CONCLUSIONS

A calcium volume percent of >18.7% was associated with a higher percent residual stenosis, and a calcium volume percent of >8.2% was associated with higher in-stent stenosis at 36 months. There was one clinically diagnosed stroke during the follow-up period, demonstrating the overall safety of the procedure.

Risk of Stroke, Death, and Myocardial Infarction Following Transcarotid Artery Revascularization vs Carotid Endarterectomy in Patients With Standard Surgical Risk

Importance

Carotid artery stenting has been limited to use in patients with high surgical risk; outcomes in patients with standard surgical risk are not well known.

Objective

To compare stroke, death, and myocardial infarction outcomes following transcarotid artery revascularization vs carotid endarterectomy in patients with standard surgical risk.

Design, Setting, and Participants

This retrospective propensity-matched cohort study was conducted from August 2016 to August 2019 with follow-up until August 31, 2020, using data from the multicenter Vascular Quality Initiative Carotid Artery Stent and Carotid Endarterectomy registries. Patients with standard surgical risk, defined as those lacking Medicare-defined high medical or surgical risk characteristics and undergoing transcarotid artery revascularization (n = 2962) or carotid endarterectomy (n = 35 063) for atherosclerotic carotid disease. In total, 760 patients were excluded for treatment of multiple lesions or in conjunction with other procedures.

Exposures

Transcarotid artery revascularization vs carotid endarterectomy.

Main Outcomes and Measures

The primary outcome was a composite end point of 30-day stroke, death, or myocardial infarction or 1-year ipsilateral stroke.

Results

After 1:3 matching, 2962 patients undergoing transcarotid artery revascularization (mean [SD] age, 70.4 [6.9] years; 1910 [64.5%] male) and 8886 undergoing endarterectomy (mean [SD] age, 70.0 [6.5] years; 5777 [65.0%] male) were identified. There was no statistically significant difference in the risk of the primary composite end point between the 2 cohorts (transcarotid 3.0% vs endarterectomy 2.6%; absolute difference, 0.40% [95% CI, -0.43% to 1.24%]; relative risk [RR], 1.14 [95% CI, 0.87 to 1.50]; P = .34). Transcarotid artery revascularization was associated with a higher risk of 1-year ipsilateral stroke (1.6% vs 1.1%; absolute difference, 0.52% [95% CI, 0.03 to 1.08]; RR, 1.49 [95% CI, 1.05 to 2.11%]; P = .02) but no difference in 1-year all-cause mortality (2.6% vs 2.5%; absolute difference, -0.13% [95% CI, -0.18% to 0.33%]; RR, 1.04 [95% CI, 0.78 to 1.39]; P = .67).

Conclusions and Relevance

In this study, the risk of 30-day stroke, death, or myocardial infarction or 1-year ipsilateral stroke was similar in patients undergoing transcarotid artery revascularization compared with those undergoing endarterectomy for carotid stenosis.

Survival, reintervention and surveillance reports: long-term, centre-level evaluation and feedback of vascular interventions

The combination of registry and administrative claims data have facilitated research and quality improvement efforts. Using Vascular Quality Initiative (VQI) registry data and Medicare claims we have generated centre-specific survival, reintervention and surveillance reports which benchmark participating centres' performance to the VQI as a whole and to published guidelines. In 2021, we distributed these reports to 303 participating centres. These reports offer an opportunity for centres to evaluate their performance and identify focus areas for quality improvement work.

Carotid Lesion Length Independently Predicts Stroke and Death After TransCarotid Artery Revascularization and TransFemoral Carotid Artery Stenting

OBJECTIVES

Prior data from the CREST trial suggested that the higher perioperative stroke or death event rate among patients treated with transfemoral carotid artery stenting (TFCAS) appears to be strongly related to the lesion length. Nonetheless, data regarding the impact of lesion length on outcomes of transcarotid artery revascularization (TCAR) with flow reversal is lacking. Herein, we aimed to compare the outcomes of TCAR versus TFCAS stratified by the length of the carotid lesion.

METHODS

Our cohort was derived from the Vascular Quality Initiative (VQI) database for carotid artery stenting between 2016 and 2021. Restricted cubic spline analysis was used to describe the relationship between the primary outcome (in-hospital stroke/death) and the exposure variable (lesion length) in the overall cohort. This relationship was not linear, and knots were identified where significant changes in the slope of the curve occurred. We therefore divided patients based on knot with the most significant inflection into two groups: lesion length<25mm (short) and lesion length ≥25mm. Clinically relevant and statistically significant variables on univariable analysis were added to the final logistic regression model clustered by center identifier to study the association between lesion length and in-hospital outcomes stratified by stent approach.

RESULTS

The study cohort included 17,931 TCAR (52.6% with long lesions), and 12,036 TFCAS (53.2% with long lesions). Patients with long lesions had higher rates of being symptomatic among both TCAR (27.2% vs 24.3%, P<0.001) and TFCAS (43.5% VS 38.5%, p<0.001) and were more likely to undergo general anesthesia in TCAR (84.7% vs 81.9%, P<0.001) and TFCAS (21.6% vs 15.8%, P<0.001). After adjusting for potential confounders, long carotid lesions were associated with higher odds of stroke, stroke/TIA and stroke/death compared to short lesions among patients undergoing TCAR or TFCAS. However, when comparing TCAR vs TFCAS outcomes in patients with long lesions, TCAR was found to be associated with 30% reduction in stroke/TIA (aOR: 0.7, 95%CI:0.6-0.9, P=0.015), stroke (aOR: 0.7, 95%CI:0.5-0.9, P=0.009), and extended length of stay (ELOS) (aOR: 0.7, 95%CI:0.6-0.8, P<0.001). There was also a 40% reduction in the odds of in-hospital stroke/death (aOR: 0.6, 95%CI:0.5-0.8, P<0.001), and 70% reduction in mortality (aOR: 0.3, 95%CI:0.2-0.4, P<0.001) in TCAR compared to TFCAS.

CONCLUSIONS

In this large contemporary retrospective national study, carotid lesion length appears to negatively impact in-hospital outcomes for TCAR and TFCAS. In the presence of lesions longer than 25 mm, TCAR appears to be safer than TFCAS with regard to the risk of in-hospital stroke, stroke/TIA, death, stroke/death and ELOS. These favorable outcomes seem to confirm the relative advantage of flow reversal compared to distal embolic protection (DEP) devices in terms of neuroprotection.

Predicting Transcarotid Artery Revascularization adverse outcomes by Imaging Characteristics

OBJECTIVES

Approximately 20-30% of ischemic strokes are caused by internal carotid artery stenosis. Stroke is the leading cause of disability and the second leading cause of death in the United States. Second generation Trans Carotid Arterial Revascularization (TCAR) stenting, using the ENROUTE flow reversal technology to prevent embolic stroke during the stenting process, has demonstrated stroke and death outcomes equivalent to CEA with reduced cranial nerve injury. However, at present, it is not known whether imaging characteristics obtained pre-operatively can predict outcomes of TCAR procedures.

METHODS

This retrospective cohort study included patients who underwent TCAR with flow reversal at 3 hospitals within a single hospital network who had CT angiography, MRI angiography or pre-operative diagnostic angiogram to determine whether carotid and lesion characteristics could predict patients who experienced Major Adverse Critical Events (MACE) versus those who did not. MACE was defined as myocardial infarction at 30 days, restenosis/persistent stenosis (peak systolic velocity within the stent >230cm/sec by post-operative ultrasound), stroke within any time of follow up or death within 1 year of TCAR. Student's t-tests and chi-squared tests were used to compare imaging characteristics, such as presence of pinpoint stenosis, calcification within the common carotid artery (CCA) at the take-off from the aorta, and plaque length in millimeters. Binomial logistic regression was used to examine the likelihood that imaging characteristics were associated with MACE.

RESULTS

Of 220 patients who underwent TCAR in our network, 7 were excluded because flow reversal was not used or appropriate imaging had not been performed prior to TCAR. Of the 213 patients that were included in analysis, the median length of follow up was 10.8 months (IQR: 3.4-33.1 months). Twelve percent (26/213) experienced a MACE, and a model based on imaging characteristics was statistically significant in predicting MACE with 68% accuracy (P=0.005). The presence of pinpoint stenosis was highly predictive of MACE (HR: 3.34, CI: 1.2 to 9.3, P=0.021). A shorter clavicle to carotid bifurcation distance was associated with an increased likelihood of experiencing a MACE (P=0.009), but it was weakly predictive (HR 1.03, CI: 1.01 to 1.05).

CONCLUSIONS

Pre-operative imaging characteristics, such as pinpoint stenosis and clavicle to carotid bifurcation distance, can be used to predict adverse outcomes in TCAR placement.

Impact of Frailty on Postoperative Outcomes in Patients undergoing TransCarotid Artery Revascularization (TCAR)

BACKGROUND

Frailty is a clinical syndrome characterized by reduction in metabolic reserves leading to increased susceptibility to adverse outcomes following invasive surgical interventions. The 5-item modified frailty index (mFI-5) validated in prior studies has shown high predictive accuracy for all surgical specialties including vascular procedures. In this study we aim to utilize the mFI-5 to predict outcomes in Transcarotid Revascularization (TCAR).

METHODS

All patient who underwent TCAR from November 2016 to April 2021 in the Vascular Quality Initiative (VQI) Database were included. The mFI-5 was calculated as a cumulative score divided by 5 with 1 point each for poor functional status, presence of diabetes, chronic obstructive pulmonary disease (COPD), congestive heart failure (CHF), and hypertension. Patients were stratified into two groups based on prior studies: low mFI-5 (0.6) and high (≥0.6). Primary outcomes included in-hospital death, extended length of postoperative stay (> 1 day), and non-home discharge. Secondary outcomes included in-hospital stroke, transient ischemic attack (TIA), myocardial infarction (MI), and composite endpoint of stroke/death, stroke/TIA and stroke/death/MI. Univariate and multivariable logistic regression were used to assess the association between mFI-5 and postoperative outcomes. Secondary analysis stratified by symptomatic status was performed.

RESULTS

Out of the 17,983 patients who underwent TCAR, 4526(25.2%) had mFI-5 score of ≥0.6 and considered clinically frail. Compared to the non-frail group, frail patients were more likely to be female (38.7% vs 35.6%, p<0.001), have poor functional status (43.6 vs 8.3%, p<0.001), and present with significant comorbidities including diabetes (75.3% vs 26.1%, p<0.001), hypertension (98.9% vs 88.5%, p<0.001), CHF (52.2% vs 5.6, p<0.001), and COPD (60.3% vs 14.2%, p<0.001). They were also more likely to be active smokers (25.4% vs 20.4%, p<0.001) and symptomatic prior to intervention (28.7% vs 25.3%, p<0.001). On univariate analysis, frail patients were at significantly higher risk to experience adverse outcomes including in-hospital mortality, TIA, MI, stroke/death, stroke/TIA, stroke/death/MI, discharge to non-home facility, and extended LOS. After adjusting for potential confounders, frail patients remained at significantly higher risk of in-hospital mortality [aOR 2.26(1.41,3.61), p=0.001], TIA [aOR 1.65(1.08, 2.54), p=0.040], non-home discharge [aOR 1.99(1.71,2.32) p<0.001], and extended LOS [aOR 1.41(1.27, 1.55) p<0.001]. On further stratified analysis based on symptomatic status, the increased risk of stroke/death, TIA, and death was observed only in symptomatic patients.

CONCLUSION

Modified Frailty Index is a reliable tool that can be used to identify high risk patients for TCAR prior to intervention. This could help vascular surgeons, patients, and families in informed decision making to further optimize perioperative care and medical management in frail patients.