Association of Transcarotid Artery Revascularization vs Transfemoral Carotid Artery Stenting With Stroke or Death Among Patients With Carotid Artery Stenosis | Cerebrovascular Disease | JAMA | JAMA Network
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Figure 1.  Trend in Transcarotid Artery Revascularization and Transfemoral Carotid Artery Stenting in the Vascular Quality Initiative
Trend in Transcarotid Artery Revascularization and Transfemoral Carotid Artery Stenting in the Vascular Quality Initiative

Yellow shading indicates the trend during the study period.

Figure 2.  Kaplan-Meier Estimated Stroke or Death in Patients Undergoing Transcarotid Artery Revascularization or Transfemoral Carotid Artery Stenting
Kaplan-Meier Estimated Stroke or Death in Patients Undergoing Transcarotid Artery Revascularization or Transfemoral Carotid Artery Stenting

Median observation time for transcarotid artery revascularization was 286 days (interquartile range [IQR], 35 to 371), and for transfemoral carotid artery stenting was 294 days (IQR, 36 to 393; hazard ratio, 0.52 [95% CI, 0.41 to 0.66]; P<.001).

Table 1.  Baseline Characteristics of Patients Before and After Propensity-Score Matching
Baseline Characteristics of Patients Before and After Propensity-Score Matching
Table 2.  In-Hospital Perioperative Outcomes After Transcarotid Artery Revascularization or Transfemoral Carotid Artery Stenting in a Propensity Score–Matched Study Population
In-Hospital Perioperative Outcomes After Transcarotid Artery Revascularization or Transfemoral Carotid Artery Stenting in a Propensity Score–Matched Study Population
Table 3.  In-Hospital Perioperative Outcomes After Transcarotid Artery Revascularization or Transfemoral Carotid Artery Stenting for Symptomatic and Asymptomatic Patients in a Propensity Score–Matched Study Population
In-Hospital Perioperative Outcomes After Transcarotid Artery Revascularization or Transfemoral Carotid Artery Stenting for Symptomatic and Asymptomatic Patients in a Propensity Score–Matched Study Population
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Original Investigation
December 17, 2019

Association of Transcarotid Artery Revascularization vs Transfemoral Carotid Artery Stenting With Stroke or Death Among Patients With Carotid Artery Stenosis

Author Affiliations
  • 1Division of Vascular and Endovascular Surgery, Department of Surgery, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts
  • 2Division of Vascular and Endovascular Therapy, Department of Surgery, Maine Medical Center, Portland
  • 3Section of Vascular Surgery and The Dartmouth Institute, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire
  • 4Division of Vascular and Surgery and Endovascular Therapy, Department of Surgery, University Hospitals Cleveland Medical Center, Cleveland, Ohio
  • 5Division of Vascular Surgery and Endovascular Therapy, Department of Surgery, Hospital of the University of Pennsylvania, Philadelphia
  • 6Division of Vascular Surgery, Department of Surgery, Indiana University School of Medicine, Indianapolis
  • 7Division of Vascular and Endovascular Surgery, Department of Surgery, University of California San Diego Health System, San Diego
JAMA. 2019;322(23):2313-2322. doi:10.1001/jama.2019.18441
Key Points

Question  Is transcarotid artery revascularization or transfemoral carotid artery stenting associated with a lower risk of stroke or death among patients undergoing treatment for carotid artery stenosis?

Findings  In this propensity score–matched analysis of data from 3286 matched pairs of patients who underwent transcarotid artery revascularization or transfemoral carotid artery stenting, the risk of in-hospital stroke or death was 1.6% with the transcarotid approach vs 3.1% with the transfemoral approach, a difference that was statistically significant.

Meaning  Among patients undergoing treatment for carotid stenosis, transcarotid artery revascularization, compared with transfemoral carotid artery stenting, was associated with a lower risk of stroke or death.

Abstract

Importance  Several trials have observed higher rates of perioperative stroke following transfemoral carotid artery stenting compared with carotid endarterectomy. Transcarotid artery revascularization with flow reversal was recently introduced for carotid stenting. This technique was developed to decrease stroke risk seen with the transfemoral approach; however, its outcomes, compared with transfemoral carotid artery stenting, are not well characterized.

Objective  To compare outcomes associated with transcarotid artery revascularization and transfemoral carotid artery stenting.

Design, Setting, and Participants  Exploratory propensity score–matched analysis of prospectively collected data from the Vascular Quality Initiative Transcarotid Artery Surveillance Project and Carotid Stent Registry of asymptomatic and symptomatic patients in the United States and Canada undergoing transcarotid artery revascularization and transfemoral carotid artery stenting for carotid artery stenosis, from September 2016 to April 2019. The final date for follow-up was May 29, 2019.

Exposures  Transcarotid artery revascularization vs transfemoral carotid artery stenting.

Main Outcomes and Measures  Outcomes included a composite end point of in-hospital stroke or death, stroke, death, myocardial infarction, as well as ipsilateral stroke or death at 1 year. In-hospital stroke was defined as ipsilateral or contralateral, cortical or vertebrobasilar, and ischemic or hemorrhagic stroke. Death was all-cause mortality.

Results  During the study period, 5251 patients underwent transcarotid artery revascularization and 6640 patients underwent transfemoral carotid artery stenting. After matching, 3286 pairs of patients who underwent transcarotid artery revascularization or transfemoral carotid artery stenting were identified (transcarotid approach: mean [SD] age, 71.7 [9.8] years; 35.7% women; transfemoral approach: mean [SD] age, 71.6 [9.3] years; 35.1% women). Transcarotid artery revascularization was associated with a lower risk of in-hospital stroke or death (1.6% vs 3.1%; absolute difference, −1.52% [95% CI, −2.29% to −0.75%]; relative risk [RR], 0.51 [95% CI, 0.37 to 0.72]; P < .001), stroke (1.3% vs 2.4%; absolute difference, −1.10% [95% CI, −1.79% to −0.41%]; RR, 0.54 [95% CI, 0.38 to 0.79]; P = .001), and death (0.4% vs 1.0%; absolute difference, −0.55% [95% CI, −0.98% to −0.11%]; RR, 0.44 [95% CI, 0.23 to 0.82]; P = .008). There was no statistically significant difference in the risk of perioperative myocardial infarction between the 2 cohorts (0.2% for transcarotid vs 0.3% for the transfemoral approach; absolute difference, −0.09% [95% CI, −0.37% to 0.19%]; RR, 0.70 [95% CI, 0.27 to 1.84]; P = .47). At 1 year using Kaplan-Meier life-table estimation, the transcarotid approach was associated with a lower risk of ipsilateral stroke or death (5.1% vs 9.6%; hazard ratio, 0.52 [95% CI, 0.41 to 0.66]; P < .001). Transcarotid artery revascularization was associated with higher risk of access site complication resulting in interventional treatment (1.3% vs 0.8%; absolute difference, 0.52% [95% CI, −0.01% to 1.04%]; RR, 1.63 [95% CI, 1.02 to 2.61]; P = .04), whereas transfemoral carotid artery stenting was associated with more radiation (median fluoroscopy time, 5 minutes [interquartile range {IQR}, 3 to 7] vs 16 minutes [IQR, 11 to 23]; P < .001) and more contrast (median contrast used, 30 mL [IQR, 20 to 45] vs 80 mL [IQR, 55 to 122]; P < .001).

Conclusions and Relevance  Among patients undergoing treatment for carotid stenosis, transcarotid artery revascularization, compared with transfemoral carotid artery stenting, was significantly associated with a lower risk of stroke or death.

Introduction

Among patients with carotid artery stenosis, carotid endarterectomy is the established treatment standard for carotid revascularization, although transfemoral carotid artery stenting has been used as an alternative technique for patients at high surgical risk for endarterectomy. Several studies have shown that transfemoral carotid artery stenting has a higher periprocedural stroke risk compared with carotid endarterectomy, particularly in patients who are symptomatic and elderly.1-4Quiz Ref ID In 2015, transcarotid artery revascularization, with a specially designed transcarotid flow reversal neuroprotection system, was developed as a new technique for carotid stenting. In contrast with the transfemoral approach, transcarotid artery revascularization avoids catheter manipulation in the aortic arch by direct carotid access and initiates cerebral protection through an extracorporeal arteriovenous shunt from the carotid artery to femoral vein prior to manipulating the target lesion.

With approval from the Centers for Medicare & Medicaid Services (CMS) and the United States Food and Drug Administration (FDA), the Transcarotid Artery Revascularization Surveillance Project5 was created to evaluate outcomes after transcarotid artery revascularization with flow reversal for patients with high surgical risk in clinical practice, without the limitations to highly selected patients and physicians typical of randomized trials. Preliminary analysis from this registry showed no significant difference in in-hospital stroke or death outcomes between transcarotid artery revascularization and endarterectomy, but significantly lower rates of cranial nerve injuries and decreased operative time with transcarotid artery revascularization.6 Using data collected until December 2017, transcarotid artery revascularization was found to be associated with lower neurological complications, based on embolic events manifested as transient ischemic attacks compared with transfemoral carotid artery stenting, but at the time, the study was limited to a small sample size.7 Therefore, the aim of this study was to provide an updated exploratory analysis of patients undergoing transcarotid artery revascularization and transfemoral carotid artery stenting from the launch of the Transcarotid Surveillance Project in September 2016 to April 2019.

Methods
Data Set

The institutional review board at Beth Israel Deaconess Medical Center approved this study and gave permission to use the data from the Society for Vascular Surgery Vascular Quality Initiative Transcarotid Artery Revascularization Surveillance Project and the Transfemoral Carotid Artery Stent Registry without the need for informed consent due to the deidentified nature of the data. The Transfemoral Carotid Artery Stent Registry is a CMS-approved prospective study, and it is utilized by clinicians to obtain reimbursement for transcarotid artery revascularization procedures. Both the transcarotid artery revascularization and transfemoral carotid artery stent registries contain more than 250 patient- and procedure-specific variables and in-hospital outcome data from more than 280 centers and 1000 physicians in the United States and Canada. Additionally, 30-day and 1-year mortality rates are determined through linkage to the Social Security Death Index. The Society for Vascular Surgery Patient Safety Organization initiated this project to evaluate the outcomes of transcarotid artery revascularization in patients with high surgical risk using FDA-approved devices labeled for the transcarotid approach. Carotid revascularization procedures in this registry were performed by vascular surgeons, cardiologists, neurosurgeons, general surgeons, neurologists, and radiologists. Patients with asymptomatic or symptomatic carotid disease were eligible for carotid stenting.

Patients

Quiz Ref IDAll patients undergoing transcarotid artery revascularization with an FDA-approved transcarotid neuroprotection system and transfemoral carotid artery stenting with documented femoral artery access were identified from September 2016 to April 2019. The final date for data collection was May 29, 2019. For all participating centers, billing data from each institution were reviewed to ensure capture of all procedures and outcomes, including failed attempted procedures and failed placement of embolic protection devices. To evaluate treatment of only atherosclerotic or intimal hyperplastic disease, patients with traumatic, dissection, and uncharacterized carotid lesions were excluded. Patients in whom carotid stents were placed in conjunction with planned intracranial procedures and those with unknown presenting symptom status or unknown symptom severity (ie, transient ischemic attack vs stroke) were also excluded.

Variable Definitions

Race and ethnicity were documented and analyzed in this study because prior studies have suggested that these features modify response to carotid revascularization procedures.8,9 Race was self-reported, obtained by review of the electronic medical record, and categorized as black, white, Asian, or other. Ethnicity was also self-reported and categorized as Hispanic or non-Hispanic. Coronary artery disease was defined as history of myocardial infarction, stable angina, or unstable angina. P2Y12 inhibitors included clopidogrel, prasugrel, ticlopidine, and ticagrelor. Preoperative medication use was documented if taken within 36 hours of the procedure, except for anticoagulants, which were recorded if taken up to 30 days before the procedure. CMS provides a list of several high-risk medical and anatomic factors used to identify patients at higher risk for carotid endarterectomy in whom carotid stenting would be reimbursed.10 Patients were recorded as high-medical risk or high-surgical risk if they met at least 1 high-risk CMS criterion. Using deidentified unique physician and center identification numbers, physician and center procedural volume was determined by the number of carotid stent procedures performed within the previous 12 months of the index procedure. Based on this volume, physicians and centers were divided into quintiles. Low volume consisted of the lowest quintile, high volume of the highest quintile, and medium volume as the middle 3 quintiles.

Outcomes

Exploratory outcomes included in-hospital stroke or death (a composite end point), stroke, death, myocardial infarction, and transient ischemic attack, as well as ipsilateral stroke or death at 30 days and at 1 year. Additional outcomes included heart failure exacerbation, access site bleeding complication, hypotensive or hypertensive hemodynamic instability, reperfusion syndrome, technical failure, embolic device placement failure, procedure time, fluoroscopy time, contrast usage, length of stay, and discharge disposition. In-hospital stroke was defined as either ipsilateral or contralateral, cortical or vertebrobasilar, ischemic or hemorrhagic stroke. Stroke was determined clinically by perioperative neurological symptoms with or without imaging confirmation. Patients were seen for follow-up at 30 days and 1 year by the treatment team, and stroke symptoms were queried and determined by reported interval history, physical examination, and review of the electronic medical record. Transient ischemic attacks were defined as focal neurological symptoms lasing less than 24 hours and were not included in the primary end point of stroke or death. Myocardial infarction was defined as clinical symptoms (chest pain or radiation to the left arm or jaw) or electrocardiogram changes occurring in conjunction with abnormal troponin elevation. Troponin rise alone was not considered a myocardial infarction. Technical failure was defined as inability to access the common carotid artery, to cross the carotid lesion, or to deploy the carotid stent. Embolic protection failure was documented if the embolic protection device could not be inserted. Bleeding complication was defined as any access site bleeding resulting in hematoma or pseudoaneurysm formation. Quiz Ref IDBleeding complications were further characterized as those associated with interventional treatment, such as surgical re-exploration or thrombin injection, or those associated with blood transfusions. Hemodynamic instability was defined as postoperative hypertension or hypotension treated with more than 1 dose or continuous infusion of intravenous blood pressure medications for 15 minutes or longer. Reperfusion syndrome was defined as postoperative headaches associated with seizures or hemorrhage seen on brain imaging. As a quality metric reported by CMS, patients with failed discharge home or prolonged length of stay were identified. Prolonged length of stay was defined as length of stay extending beyond 2 days. Discharge to home was defined as the event when patients were discharged to where they resided prior to the operation, even if their home was a nursing home. Procedure time was recorded from time of skin access puncture or incision to sheath removal or skin closure.

Statistical Analyses

Preliminary analysis of this registry7 found that a sample size of 5041 patients in each cohort would achieve a power of 80%, based on a stroke or death rate of 2.5% following transcarotid artery revascularization vs 1.7% following transfemoral carotid artery stenting. After comparing baseline characteristics between patients undergoing transcarotid artery revascularization vs transfemoral carotid artery stenting, propensity scores were generated for each covariate (Table 1) using log-odds. Treatment cohorts were matched on these propensity scores using a calibration of 0.1 absolute units, and intergroup differences were tested with the McNemar test for categorical variables and paired t test or Wilcoxon matched-pairs signed-rank test for continuous variables as appropriate. All variables had less than 5% missing data. Interaction terms were used to test for effect modification using regression analysis. Because there was a significant interaction found between presenting symptom status and procedure type for the outcome of stroke or death, propensity-matched analyses were performed for patients with asymptomatic and symptomatic carotid disease.

The difference in the probability of outcome events in the matched cohorts was evaluated by the McNemar test and paired t tests when appropriate. Relative risk (RR) was estimated as the ratio of the probability of the outcome event in patients treated using the transcarotid approach compared with patients treated using the transfemoral approach. The 95% CIs were constructed using methods that accounted for the matched nature of the cohorts.11 Stroke or death rates in the matched cohorts were estimated at 1 year using Kaplan-Meier life-table methods, censoring patients lost to follow-up, and comparisons were made using bivariable Cox proportional hazard models. The proportionality assumption was confirmed by correlation testing based on Schoenfeld residuals. P values less than .05 were considered statistically significant and all tests were 2-sided. As all analyses were considered exploratory, no correction for multiplicity was performed. Stata/SE, version 14.1 (StataCorp) was used for all analyses.

Results
Patients

The number of transcarotid artery revascularization procedures rapidly increased since the registry began in 2016, with a concurrent decrease in the number of transfemoral carotid artery stenting procedures (Figure 1). In 2018, 46% of all carotid stenting procedures were performed via the transcarotid approach. Patients with traumatic (n = 42), dissection (n = 268), and uncharacterized (n = 553) carotid lesions or carotid stents placed in conjunction with planned intracranial procedures (n = 408) were excluded. Patients with unknown presenting symptom status (n = 890) or unknown symptom severity (n = 998) were also excluded, resulting in 11 891 patients who underwent carotid artery stenting. Of these patients, 5251 (44%) underwent transcarotid artery revascularization and 6640 (56%) underwent transfemoral carotid artery stenting. These procedures were performed by 1035 physicians from 319 centers. The majority of transcarotid procedures were performed by vascular surgeons (85%), followed by general surgeons (9%), neurosurgeons (2%), and cardiologists (1%); whereas transfemoral carotid artery stenting was performed by vascular surgeons (28%), radiologists (21%), cardiologists (20%), neurosurgeons (13%), neurologists (11%), and general surgeons (3%). Baseline characteristics and coexisting conditions before and after propensity-score matching can be found in Table 1 and unadjusted outcomes can be found in eTable 1 in the Supplement. Overall, patients undergoing transcarotid artery revascularization were older and had more medical coexisting conditions. After matching, 3286 pairs of patients remained in the study population and the 2 cohorts were well matched. Among these matched pairs, data on in-hospital stroke or death were available for all patients, and data on ipsilateral stroke or death at 1 year were available for 46% of patients undergoing transcarotid artery revascularization and 54% of patients undergoing transfemoral carotid artery stenting.

Overall Outcomes

In-hospital risk of stroke or death was 1.6% in the transcarotid cohort vs 3.1% in the transfemoral cohort (absolute difference, −1.52% [95% CI, −2.29% to −0.75%]; RR, 0.51 [95% CI, 0.37 to 0.72]; P < .001) (Table 2). Transcarotid artery revascularization was associated with significantly lower risks of both stroke (1.3% vs 2.4%; absolute difference, −1.10% [95% CI, −1.79% to −0.41%]; RR, 0.54 [95% CI, 0.38 to 0.79]; P = .001) and death (0.4% vs 1.0%; absolute difference, −0.55% [95% CI, −0.98% to −0.11%]; RR, 0.44 [95% CI, 0.23 to 0.82]; P = .008). Risks between the transcarotid and transfemoral cohorts were not statistically different for myocardial infarction (0.2% vs 0.3%; absolute difference, −0.09% [95% CI, −0.37% to 0.19%]; RR, 0.70 [95% CI, 0.27 to 1.84]; P = .47) and transient ischemic attack (0.7% vs 1.0%; absolute difference, −0.30% [95% CI, −0.77% to 0.16%]; RR, 0.69 [95% CI, 0.40 to 1.18]; P = .17).

At 30 days, the transcarotid approach was associated with significantly lower risk of stroke or death (1.9% vs 3.7%; absolute difference, −1.73% [95% CI, −2.57% to −0.90%]; RR, 0.53 [95% CI, 0.39 to 0.72]; P < .001) as well as the individual end points of stroke (1.3% vs 2.5%; absolute difference, −1.19% [95% CI, −1.89% to −0.49%]; RR, 0.53 [95% CI, 0.37 to 0.76]; P < .001) and death (0.8% vs 1.5%; absolute difference, −0.70% [95% CI, −1.24% to −0.16%]; RR, 0.52 [95% CI, 0.32 to 0.84]; P = .007). At 1 year, the transcarotid approach was associated with a significantly lower risk of ipsilateral stroke or death compared with the transfemoral approach (5.1% vs 9.6%; hazard ratio, 0.52 [95% CI, 0.41 to 0.66]; P < .001) (Figure 2).

Transcarotid artery revascularization was associated with significantly lower rates of technical failure (0.5% vs 1.2%; absolute difference, −0.79% [95% CI, −1.27% to −0.32%]; RR, 0.37 [95% CI, 0.20 to 0.66]; P < .001). Embolic protection placement failure was significantly lower for the transcarotid approach compared with distal filter placement for the transfemoral approach (0.3% vs 5.8%; absolute difference, −5.54% [95% CI, −6.40% to −4.69%]; RR, 0.05 [95% CI, 0.02 to 0.09]; P < .001). The transcarotid approach was associated with significantly less radiation (median fluoroscopy time, 5 minutes [interquartile range {IQR}, 3 to 7] vs 16 minutes [IQR, 11 to 23]; P < .001) and less contrast (median contrast used, 30 mL [IQR, 20 to 45] vs 80 mL [IQR, 55 to 122]; P < .001). Although there were no statistically significant differences in overall access site bleeding complications (3.5% vs 3.8%; absolute difference, −0.27% [95% CI, −0.01% to 0.66%]; RR, 0.93 [95% CI, 0.72 to 1.19]; P = .55), transcarotid artery revascularization was associated with higher risks of access site bleeding resulting in interventional treatment (1.3% vs 0.8%; absolute difference, 0.52% [95% CI, −0.01% to 1.04%]; RR, 1.63 [95% CI, 1.02 to 2.61; P = .04). Patients who underwent transcarotid artery revascularization were significantly less likely than patients who underwent transfemoral carotid artery stenting to fail the CMS-recommended discharge criteria (16.4% vs 22.7%; absolute difference, −6.30% [95% CI, −8.21% to −4.39%]; RR, 0.72 [95% CI, 0.66 to 0.80]; P < .001), including length of stay greater than 2 days (13.9% vs 19.0%; absolute difference, −5.11% [95% CI, −6.91% to −3.31%]; RR, 0.73 [95% CI, 0.66 to 0.82]; P < .001), and failed discharge home (7.3% vs 12.7%; absolute difference, −5.42% [95% CI, −6.90% to −3.94%]; RR, 0.57 [95% CI, 0.49 to 0.67]; P < .001).

Symptomatic Carotid Stenosis

There was interaction between presenting symptom status and the outcomes of in-hospital stroke or death (P value for interaction = .007), stroke (P value for interaction = .09), and death (P value for interaction = .007). Propensity-score matching of patients with symptomatic carotid disease resulted in 1829 pairs (eTable 2 in the Supplement). Transcarotid artery revascularization was associated with significantly lower risk of in-hospital stroke or death (2.1% vs 4.2%; absolute difference, −2.02% [95% CI, −3.21% to −0.83%]; RR, 0.51 [95% CI, 0.35 to 0.75]; P < .001), stroke (2.0% vs 3.1%; absolute difference, −1.10% [95% CI, −2.17% to −0.02%]; RR, 0.64 [95% CI, 0.42 to 0.97]; P = .04), and death (0.5% vs 1.5%; absolute difference, −1.04% [95% CI, −1.74% to −0.33%]; RR, 0.32 [95% CI, 0.15 to 0.68]; P = .002) (Table 3). There were no statistically significant differences in overall bleeding complications (4.0% vs 4.1%; absolute difference, −0.05% [95% CI, −1.40% to 1.29%]; RR, 0.99 [95% CI, 0.72 to 1.36]; P = .93) or bleeding reinterventions (1.3% vs 0.7%; absolute difference, 0.49% [95% CI, −0.20% to 1.19%]; RR, 1.69 [95% CI, 0.85 to 3.36]; P = .13) between the 2 cohorts (Table 3).

Asymptomatic Carotid Stenosis

After propensity matching patients with asymptomatic disease, 1438 pairs of patients remained (eTable 3 in the Supplement). There was no statistically significant difference in in-hospital stroke or death (1.0% vs 1.5%; absolute difference, −0.42% [95% CI, −1.30% to 0.47%]; RR, 0.71 [95% CI, 0.37 to 1.39]; P = .32), stroke (0.7% vs 1.3%; absolute difference, −0.56% [95% CI, −1.35% to 0.23%]; RR, 0.56 [95% CI, 0.26 to 1.20]; P = .13), and death (0.4% vs 0.2%; absolute difference, 0.21% [95% CI, −0.27% to 0.69%]; RR, 2.00 [95% CI, 0.50 to 8.00]; P = .32). Although there were no statistically significant differences in overall bleeding complications (2.6% vs 2.8%; absolute difference, −0.21% [95% CI, −1.43% to 1.01%]; RR, 0.93 [95% CI, 0.60 to 1.42]; P = .72), transcarotid artery revascularization was associated with higher risks of bleeding reinterventions (1.3% vs 0.5%; absolute difference, 0.77% [95% CI, 0.04% to 1.49%]; RR, 2.57 [95% CI, 1.11 to 5.94]; P = .02) (Table 3).

Discussion

Quiz Ref IDIn this prospective registry that evaluated patients undergoing treatment for carotid stenosis, transcarotid artery revascularization, compared with transfemoral carotid artery stenting, was associated with a lower risk of stroke or death. For several decades, carotid endarterectomy has been the criterion standard for carotid revascularization, with perioperative stroke or death rates typically less than 2 percent for asymptomatic patients.12-14 Transfemoral carotid artery stenting was introduced in 1996 as an alternative, more minimally invasive technique.15 However, several randomized trials have since identified an increased risk of stroke following transfemoral carotid artery stenting compared with endarterectomy.1-4 For example, the CREST trial (Carotid Revascularization Endarterectomy Versus Stenting Trial) compared endarterectomy and carotid stenting before the introduction of the transcarotid approach and found higher rates of 30-day perioperative stroke after transfemoral carotid artery stenting compared with endarterectomy (4.1% vs 2.3%; P = .01), most notably in the treatment of symptomatic patients (5.5% vs 3.2%; P = .04).1 Additional randomized trials and large retrospective database studies have now further confirmed the higher perioperative stroke risk associated with transfemoral carotid artery stenting.16-19

Quiz Ref IDAs a response to the high rates of perioperative stroke with transfemoral carotid artery stenting, transcarotid revascularization with flow reversal was developed as a new carotid stenting technique, specifically to avoid the high-risk maneuvers that have been associated with transfemoral carotid artery stenting, including manipulation of the aortic arch to cannulate the common carotid artery and crossing the carotid lesion unprotected to deploy the embolic protection filter distally.20,21 Even when deployed, filter devices can allow passage of small embolic particles through their pores or around the filter if incompletely apposed to the vessel wall.22,23 Transcarotid artery revascularization avoids the aortic arch with direct common carotid access and utilizes flow reversal prior to crossing the lesion. In patients with carotid disease, 68% of carotid arteries have been found to be anatomically eligible for the transcarotid approach, and 79% are eligible for the transfemoral approach, indicating a wide range of suitability for either procedure.24

The theoretical benefits with transcarotid artery revascularization were first confirmed clinically in the multicenter single-group ROADSTER trial (Safety and Efficacy Study for Reverse Flow Used During Carotid Artery Stenting Procedure), which showed a 30-day stroke rate of 1.4% and 95% stroke-free survival at 1 year.25,26 This study found a similar but slightly lower perioperative stroke rate of 1.2% following transcarotid artery revascularization compared with the ROADSTER trial. Similarly, the 30-day perioperative stroke or death rate of 3.7% in this study was also lower than that found for transfemoral carotid artery stenting in randomized clinical trials such as CREST (4.4%). This difference is likely attributable to an underreporting of stroke events as patients were not assessed for potential stroke by neurologists, and the nonneurologic assessors did not use formal operationalized neurologic examinations and structured interviews to detect stroke symptoms and signs.

Whereas transcarotid artery revascularization was associated with a statistically significant decrease in stroke rates compared with transfemoral carotid artery stenting for treatment of symptomatic patients, there was no statistically significant difference in stroke rates for treatment of asymptomatic patients. However, the study may have been underpowered to detect an association given the overall low event rates in asymptomatic patients.

Several trials have shown a reduction in perioperative myocardial infarctions with transfemoral carotid artery stenting compared with endarterectomy, likely attributable to its more minimally invasive approach.16,18 Transcarotid artery revascularization, which also uses a less invasive approach than endarterectomy, showed no significant difference in perioperative myocardial infarction profile as compared with transfemoral carotid artery stenting in both asymptomatic and symptomatic patients. These benefits were found despite the higher rates of bleeding complications associated with intervention following transcarotid artery revascularization.

Limitations

This study has several limitations. First, treatment options were not randomized but were selected by the treating physician, introducing the possibility of confounding by indication. Second, because of the study’s observational design, causal inferences cannot be made. Third, because the end point of stroke was determined clinically by perioperative neurological symptoms and there was no requirement for formalized neurologic testing or imaging, this study is subject to ascertainment bias. Fourth, clinical registries are subject to selection bias since not all US hospitals participate. Although not all patients undergoing carotid stenting nationally are captured in this study, based on industry reporting,27 95.4% of all transcarotid procedures utilizing flow reversal performed in the United States are recorded in this registry. Fifth, while this registry contains multiple predefined anatomic and medical variables specific to carotid disease, unmeasured confounding may still be present. Sixth, this study’s definition of transient ischemic attack was based on focal neurological symptoms lasting less than 24 hours and does not reflect the current definition of transient ischemic attack set forth by the American Heart Association and American Stroke Association. Seventh, there are no details captured to differentiate between ischemic vs hemorrhagic strokes nor guidance provided regarding classifying location of subcortical anterior circulation and occipital cortex strokes. Eighth, 1-year follow-up is not complete for all patients in the study. However, this is accounted for with Kaplan-Meier censoring, and multiple randomized trials have demonstrated no statistically significant difference in stroke or death occurring beyond the perioperative period between stenting and endarterectomy, so there is no reason to suspect that adverse events past this study period would be different for transcarotid vs transfemoral stents.28,29

Conclusions

Among patients undergoing treatment for carotid stenosis, transcarotid artery revascularization, compared with transfemoral carotid artery stenting, was significantly associated with a lower risk of stroke or death.

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Article Information

Corresponding Author: Marc L. Schermerhorn, MD, Beth Israel Deaconess Medical Center, 110 Francis St, Ste 5B, Boston, MA 02215 (mscherm@bidmc.harvard.edu).

Accepted for Publication: October 19, 2019.

Author Contributions: Drs Schermerhorn and Liang had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis. Drs Schermerhorn and Liang contributed equally to this article.

Concept and design: Schermerhorn, Liang, Eldrup-Jorgensen, Cronenwett, Motaganahalli, Malas.

Acquisition, analysis, or interpretation of data: Schermerhorn, Liang, Nolan, Kashyap, Wang.

Drafting of the manuscript: Schermerhorn, Liang.

Critical revision of the manuscript for important intellectual content: All authors.

Statistical analysis: Schermerhorn, Liang, Kashyap.

Administrative, technical, or material support: Schermerhorn, Cronenwett.

Supervision: Schermerhorn, Eldrup-Jorgensen, Wang, Malas.

Conflict of Interest Disclosures: Dr Schermerhorn reported receipt of personal fees for provision of consultancy services from Silk Road Medical, Abbott, Cook, Endologix and Medtronic outside the submitted work. Dr Kashyap reported being a national coprimary investigator for the Safety and Efficacy Study for Reverse Flow Used During Carotid Artery Stenting Procedure (ROADSTERII). Dr Motaganahalli reported other for provision of consultancy services from Silk Road Medical during the conduct of the study. Dr Malas reported being a site principal investigator for the Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis Trial (CREST-2) and the ROADSTERI and ROADSTERII trials, a national primary investigator for the ROADSTERI long-term follow-up study, and being a proctor for TCAR. No other disclosures were reported.

Funding/Support: Dr Liang is supported by the Harvard-Longwood Research Training in Vascular Surgery National Institutes of Health (NIH) T32 grant (5T32HL007734-22). This work was conducted with support from Harvard Catalyst—The Harvard Clinical and Translational Science Center (National Center for Research Resources and the National Center for Advancing Translational Sciences, NIH award (UL1 TR001102), and financial contributions from Harvard University and its affiliated academic health care centers.

Role of the Funder/Sponsor: The Society for Vascular Surgery Patient Safety Organization was not involved in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.

Disclaimer: The content is solely the responsibility of the authors and does not necessarily represent the official views of Harvard Catalyst, Harvard University and its affiliated academic health care centers, or NIH.

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