Predictors and timing of hypotension and bradycardia after carotid artery stenting

[Drug therapy for acute and elective stent angioplasty]

CLINICAL ISSUE

Carotid artery stenoses are constrictions of the common carotid artery and the internal carotid artery. They cause around 15% of all cerebral ischemia, which is why their detection and correct treatment play an important role in clinical practice.

PRACTICAL RECOMMENDATIONS

Depending on the severity and clinical symptoms, carotid artery stenosis is treated conservatively, surgically or endovascularly by means of stent angioplasty. In the case of stent angioplasty in particular, correct drug therapy plays an important role in avoiding/reducing thromboembolic complications.

The role of periprocedural hemodynamic variables during carotid stenting for the mid-term general mortality in advanced age patients

INTRODUCTION

Carotid stenting may produce significant bradycardia and/or hypotension. This may have negative short- and long-term effects for the elderly high-risk patients. Their cerebral hemodynamics is with exhausted adaptive capacity because of the multiple cardiovascular risk factors, advanced age, and significant stenosis.

Continuous Monitoring of Changes in Heart Rate during the Periprocedural Course of Carotid Artery Stenting Using a Wearable Device: A Prospective Observational Study

This prospective observational study will evaluate the change in heart rate (HR) during the periprocedural course of carotid artery stenting (CAS) via continuous monitoring using a wearable device. The participants were recruited from our outpatient clinic between April 2020 and March 2023. They were instructed to continuously wear the device from the last outpatient visit before admission to the first outpatient visit after discharge. The changes in HR of interest throughout the periprocedural course of CAS were assessed. In addition, the Bland-Altman analysis was adopted to compare the HR measurement made by the wearable device during CAS with that made by the electrocardiogram (ECG). A total of 12 patients who underwent CAS were included in the final analysis. The time-series analysis revealed that a percentage change in HR decrease occurred on day 1 following CAS and that the most significant HR decrease rate was 12.1% on day 4 following CAS. In comparing the measurements made by the wearable device and ECG, the Bland-Altman analysis revealed the accuracy of the wearable device with a bias of -1.12 beats per minute (bpm) and a precision of 3.16 bpm. Continuous HR monitoring using the wearable device indicated that the decrease in HR following CAS could persist much longer than previously reported, providing us with unique insights into the physiology of carotid sinus baroreceptors.

Treatment via oral midodrine in a patient with prolonged hypotension following carotid artery stenting: a case report

Background

Hypotension and bradycardia are common hemodynamic complications following carotid artery stenting in patients with carotid artery stenosis. Intravenous fluid resuscitation and inotropes such as dopamine are conventional treatments for post-carotid artery stenting hypotension. However, in case of resistant hypotension, there is no clear treatment method. In this report, while intravenous fluid and inotropes did not resolve the patient’s hypotension, oral midodrine treated post-carotid artery stenting hypotension.

Case presentation

In this report, we present an 82-year-old Caucasian man complaining of a single episode of unilateral visual loss. The patient had left internal carotid artery stenosis and underwent carotid artery stenting. After the procedure, he developed prolonged post-carotid artery stenting hypotension, which was resistant to intravenous fluids and inotropes but immediately showed a promising response to oral midodrine.

Conclusion

Oral midodrine can be considered in treatment of post-carotid artery stenting hemodynamic complications.

Hemodynamic depression after carotid surgery: Incidence, risk factors and outcomes

INTRODUCTION

Hemodynamic Depression (HD) characterized by hypotension and bradycardia is a complication of carotid surgery due to direct autonomic stimulation in the carotid sinus. The authors believe the incidence of HD is high and possibly related to major cardiac complications.

METHODS

Analysis of patient records during admissions for carotid surgery between January 2014 and December 2018 in two hospitals. HD was defined as bradycardia or hypotension in the first 24 postoperative hours. Bradycardia was defined as heart rate < 50bpm; hypotension as systolic blood pressure < 90 mmHg, continuous use of vasopressors, or a drop in SBP > 20% compared to preoperative values. Myocardial infarction, stroke, and cardiovascular death were defined as adverse events.

RESULTS

Overall, 237 carotid surgeries (178 endarterectomies, 59 angioplasties) were studied, and the global incidence of HD was 54.4% (hypotension in 50.2%, bradycardia in 11.0%, and hypotension and bradycardia in 6.8%). The independent predictors of HD were asymptomatic carotid stenosis (OR = 1.824; 95% CI 1.014-3.280; p = 0.045), endovascular surgery (OR = 3.319; 95% CI 1.675-6.576; p = 0.001) and intraoperative hypotension or bradycardia (OR = 2.144; 95% CI 1.222-3.762; p = 0.008). Hypotension requiring continuous vasopressor infusion was the only factor independently associated with adverse cardiovascular events (OR = 5.504; 95% CI 1.729-17.529; p = 0.004).

DISCUSSION/CONCLUSION

Incidence of Hemodynamic Depression after carotid surgery is high and independently associated with surgical technique, symptomatic repercussion of the carotid stenosis, and intraoperative hypotension or bradycardia. Hypotension requiring the continuous infusion of vasopressors was independently associated with the occurrence of MACE.

Plaque Characteristics on CT Angiography Do Not Improve the Ability to Predict Hemodynamic Instability During and After Carotid Angioplasty and Stenting

BACKGROUND

Hemodynamic instability is commonly seen during carotid angioplasty and stenting. Although prophylactic treatment with anticholinergics is beneficial, selected use in high-risk patients is desirable. This study examines whether plaque characteristics on computed tomography angiography in addition to demographic factors improve predictive capability.

METHODS

We retrospectively collected information from 298 carotid angioplasty procedures between January 2013 and December 2018. Nine individuals were excluded due to a previous ipsilateral endarterectomy. Our primary outcome was a decrease of 20% or more in heart rate or blood pressure at angioplasty. Data were analyzed using χ2 tests and regression statistics.

RESULTS

Of the 289 patients included for analysis, 57 had intraoperative instability and 26 had postoperative instability. Radiologist interpretation was found to have a risk ratio of 1.63 (95% confidence interval: 1.00-2.65) for intraoperative instability (P=0.080). Intraoperative instability was significantly associated with subsequent postoperative instability (P=0.005). Our regression model included previous endarterectomy and diabetes as predictive factors with a sensitivity of 11.3% and a specificity of 100.0%. Anticholinergic usage was associated with hypotension without coexisting bradycardia with a risk ratio of 2.36 (95% confidence interval: 1.06-5.26; P=0.047).

CONCLUSIONS

Individuals without a previous contralateral endarterectomy and/or history of diabetes are at lower risk of hemodynamic instability. The addition of computed tomography angiographic variables does not improve this prediction. Future prospective, randomized work is required to improve our ability to identify and treat individuals at high risk of instability during carotid angioplasty and stenting.

The correlation between the cardiovascular instability and the size of the developed ischaemic lesions in patients who underwent carotid stenting

AIMS

In this study we investigated the relationship between cardiovascular instability and the size of the developed ischaemic lesions during carotid stent implantation by diffusion-weighted (DWI) magnetic resonance (MR) examination.

MATERIAL AND METHODS

We retrospectively analyzed anaesthesia reports and follow-up MR examinations after stent implantation of 192 patients in a 3-year period. Nineteen aspects of cardiovascular status were analyzed. We registered the duration of the intervention, low and high blood pressure (BP) values during anaesthesia and heart rates. The fluctuations of BP and heart rate and the time of their compensations after the stent expansion were also recorded. Values were compared with the number and the size of ischaemic lesions on DWI scans. We used Spearman and Kendall rank correlations and Welch's tests for statistical analysis. Values of p ≤ 0.05 were considered as statistically significant.

RESULTS

Decreased heart rate significantly correlated with the number (p = 0.0123) and size (p = 0.00323) of ischaemic lesions during stent expansion. Other cardiovascular parameters did not show any significant correlations.

CONCLUSIONS

Our results indicate that only heart rate attenuation affects the size of ischaemic lesions; thus the prevention of bradycardia is highly important.

Predisposing Factors and Management of Hemodynamic Depression Following Carotid Artery Stenting

Carotid artery stenting (CAS) involves dilatation of carotid bulb which can trigger a series of neuronal responses resulting in hemodynamic depression that might influence the outcome of the procedure. This is a frequent but underdiagnosed complication of CAS. Although it is mild, transient and self-limiting in majority of cases, it can result in significant morbidity and mortality if persistent. Neurologists should be aware of the predisposing factors and management of this common complication. In patients who present with stroke following carotid stenting, neurologists should be aware of hypoperfusion secondary to hemodynamic depression as a cause of stroke apart from the stent thrombosis and occlusion.

Incidence and predictors of prolonged hemodynamic depression after carotid artery stenting: Yet another benefit of statins?

OBJECTIVES

We aimed to assess the incidence and predictors of prolonged hemodynamic depression (PHD) after carotid artery stenting (CAS).

METHODS

We retrospectively analyzed data from 216 CAS procedures performed in 207 patients (156 male; median and interquartile range (IQR) of age 68 (62-73) yr) between July 2012 and October 2020. PHD was defined as hypotension (systolic blood pressure ≤ 90 mmHg) and/or bradycardia (heart rate < 60 bpm) lasting >1 h.

RESULTS

The incidence of PHD was 25.9%. At multivariate analysis, asymptomatic lesions (OR: 2.43, 95% CI (1.16-5.06), p: 0.018), the stenosis proximity (<10 mm) to bifurcation (OR: 2.94, 95% CI (1.34-6.43), p: 0.007) and implantation of a Protege stent (OR: 2.93, 95% CI (1.14-7.53), p: 0.025) were independent risk factors, while statin usage (OR: 0.48, 95% CI (0.24-0.95), p: 0.036) was an independent protective factor for PHD after CAS.

CONCLUSIONS

Patients with asymptomatic lesions and stenosis close to the bifurcation are more prone to PHD. The type of the stent selected significantly influences the risk of PHD. Further prospective randomized studies are warranted to investigate the possible protective role of statins against PHD after CAS.

Risk factors and impact of postoperative hypotension after carotid artery stenting in the Vascular Quality Initiative

OBJECTIVE

Hypotension is a frequent complication of carotid artery stenting (CAS). Although common, its occurrence is unpredictable, and association with adverse events has not been well defined. The aim of this study was to identify predictors of postoperative hypotension after CAS and the association with stroke/transient ischemic attack (TIA), major adverse cardiac events (MACEs), increased length of stay (LOS), and in-hospital mortality.

METHODS

This is a retrospective analysis of all CAS procedures, including transfemoral CAS (TF-CAS) and transcarotid artery revascularization (TCAR), performed in the Vascular Quality Initiative between 2003 and 2018. The primary study end point was postoperative hypotension, defined as hypotension treated with continuous infusion of a vasoactive agent for ≥15 minutes. Secondary end points included any postoperative neurologic events (stroke/TIA), MACEs (myocardial infarction, congestive heart failure, and dysrhythmias), prolonged LOS (>1 day), and in-hospital mortality. Patients' demographics predictive of hypotension were determined by multivariable logistic regression, and a risk score was developed for correlation with outcomes.

RESULTS

During the time period of study, 24,699 patients underwent CAS; 19,716 (80%) were TF-CAS, 3879 (16%) were TCAR, and 1104 (4%) were not defined. Fifty-six percent were for symptomatic disease, 75% were for a primary atherosclerotic lesion, and 72% were performed under local or regional anesthesia. Postoperative hypotension occurred in 15% of TF-CAS and 14% of TCAR patients (P = .50). Patients with hypotension (vs no hypotension) had higher rates of stroke/TIA (7.3% vs 2.6%; P < .001), MACEs (9.6% vs 2.1%; P < .001), prolonged LOS (65% vs 28%; P < .001), and in-hospital mortality (2.9% vs 0.7%; P < .001). By multivariable analysis, risk factors associated with hypotension included an atherosclerotic (vs restenotic) lesion (odds ratio, 2.2; 95% confidence interval, 2.0-2.4; P < .001), female sex (1.3 [1.2-1.4]; P < .001), positive stress test result (1.3 [1.2-1.4]; P < .001), age 70 to 79 years (1.1 [1.1-1.3]; P < .002), age >80 years (1.2 [1.1-1.4]; P < .001), history of myocardial infarction or angina (1.3 [1.2-1.4]; P < .001), and an urgent (vs elective) procedure (1.1 [1.0-1.2]; P < .01). A history of hypertension was protective (0.9 [0.8-0.9]; P < .02). A normalized risk score for hypotension was created from the multivariable model. Increasing risk scores correlated directly with rates of adverse events, including postoperative stroke/TIA, MACEs, increased LOS, and increased in-hospital mortality.

CONCLUSIONS

Hypotension after CAS is associated with adverse neurologic and cardiac events as well as with prolonged LOS and in-hospital mortality. A scoring tool may be valuable in stratifying patients at risk. Interventions aimed at preventing postoperative hypotension may improve outcomes with CAS.

Safety of simultaneous bilateral carotid artery stenting for bilateral carotid artery stenosis

BACKGROUND

Bilateral carotid artery stenting (BCAS) is often performed in two stages (staged BCAS) but it is also an option to be performed in one stage (simultaneous BCAS). To confirm the safety of simultaneous BCAS, we retrospectively analyzed perioperative and postoperative course of simultaneous BCAS compared with staged BCAS.

MATERIALS AND METHODS

Patients with symptomatic stenosis of ≥50% or asymptomatic stenosis of ≥80% of bilateral carotid arteries underwent BCAS. Procedure time, symptomatic ischemic complications, presence/absence of high-intensity spots on postoperative diffusion-weighted image, duration of postoperative hospital stays and 30 days outcome of patients performed with simultaneous BCAS (group A, 8 patients with 16 stenotic lesions (8 procedures)) were compared with those of staged BCAS (group B, 4 patients with 8 stenotic lesions (8 procedures)).

RESULTS

In groups A and B, procedure time was 146.0 ± 53.8 and 103.5 ± 39.4 min; intraoperative hypotension was observed in 62.5% and 50.0%; postoperative hypotension occurred in 37.5% and 50.0%; diffusion-weighted image showed high-intensity spots in 37.5% and 12.5%; and duration of postoperative hospital stays was 5.1 ± 1.8 and 5.3 ± 2.3 days. No patients suffered symptomatic ischemic complications. In simultaneous BCAS, there was a tendency that procedure time was longer and high-intensity spots on postoperative diffusion-weighted image was more frequent, but there was no increase in symptomatic ischemic complications and duration of hospital stays compared to staged BCAS.

CONCLUSIONS

Safety of simultaneous BCAS may not be inferior to staged BCAS. In terms of duration of hospital stays, simultaneous BCAS can be superior to staged BCAS for patients with bilateral carotid artery stenosis.

The impact of post-dilatation on periprocedural outcomes during carotid artery stenting: A single-center experience

BACKGROUND AND AIMS

Carotid artery stenting (CAS) is an accepted treatment modality for carotid artery disease. However, CAS is associated with periprocedural embolic events, and the effect of balloon post-dilatation has not been sufficiently investigated in large studies. We assessed the effect of post-dilatation on periprocedural outcomes during CAS.

METHODS

The study included 128 patients who underwent CAS. The patients were divided into groups according to whether post-dilatation was (post-dilatation [+], group 1) or was not (post dilatation [-], group 2) performed after stent deployment. Major adverse events were defined as death, minor or major stroke, and transient ischemic attack at 30 days. Silent ischemia was assessed using diffusion-weighted magnetic resonance imaging.

RESULTS

No significant between-group differences were found in baseline characteristics, comorbid diseases, or lesion characteristics. The degree of stenosis and procedure duration was greater in group 1 than in group 2. The rate of major adverse events at 30 days was similar between the two groups (5.1% vs. 4.3%, p = 0.844). The silent ischemia rate and number of high-intensity signals were higher in group 1 than in group 2 (45.8% vs. 26.1%, p = 0.020 and 1.01 [1.2] vs. 0.42 [0.79], p = 0.002). Multivariate analysis revealed that post-dilatation was associated with a 2.4-fold increase in silent ischemia (95% confidence interval: 1.15-5.20, p = 0.020).

CONCLUSIONS

Although post-dilatation was not associated with an increase in major adverse events, it significantly increased the incidence of periprocedural silent ischemia. Therefore, post-dilation should be performed only in cases with severe residual stenosis after CAS.

Hemodynamic Surveillance of Unilateral Carotid Artery Stenting in Patients With or Without Contralateral Carotid Occlusion by TCD/TCCD in the Early Stage Following Procedure

Objective: To evaluate the cerebral hemodynamic variations in patients with unilateral carotid artery stenosis and contralateral carotid occlusion (CCO) in hours following carotid artery stenting (CAS) by transcranial Doppler (TCD) or transcranial color-code Doppler (TCCD).

Methods: Sixty-five consecutive patients who underwent unilateral CAS were enrolled. Among them, 14 patients had ipsilateral severe stenosis and CCO (CCO group) while the other 51 patients had only unilateral severe carotid stenosis without CCO (UCS group). All patients underwent TCD or TCCD monitoring before, at 1 and 3 h after CAS. We monitored bilateral middle cerebral artery (MCA) peak systolic velocity (PSV), pulsatility index (PI), and blood pressure (BP), and compared that data between two groups.

Results: In UCS group, ipsilateral MCA PSV increased relative to baseline at 1 h (96 ± 30 vs. 85 ± 26 cm/s, 15%, P < 0.001) and 3 h (97 ± 29 vs. 85 ± 26 cm/s, 17%, P < 0.001) following CAS. Significant PI increases were observed at 1 and 3 h following CAS on the ipsilateral side. In CCO group, ipsilateral MCA PSV increased relative to baseline at 1 h (111 ± 30 vs. 83 ± 26 cm/s, 35%, P < 0.001) and 3 h (107 ± 28 vs. 83 ± 26 cm/s, 32%, P <0.001) following CAS. The magnitude of ipsilateral MCA PSV increase was significantly higher in CCO group compared with UCS group at 1 h (P = 0.002) and 3 h (P = 0.024) following CAS, while BP similarly decreased between the two groups. On the contralateral side, significant MCA PSV increases were observed following CAS in CCO group but not in UCS group. Bilateral MCA PSV increases were higher in patients with a stenosis degree of ≥90% than in patients with stenosis degree of 70–89% only in CCO group.

Conclusion: The ipsilateral MCA PSV and PI increase moderately in the initial hours after unilateral CAS in patients without CCO. In patients with CCO, the ipsilateral, and contralateral MCA PSV increase significantly in the early stage following CAS. CCO is a factor of the increased blood flow velocity in ipsilateral MCA after unilateral CAS.

Multivariable Analysis of Patients With Severe Persistent Postprocedural Hypotension After Carotid Artery Stenting

Purpose: To assess the incidence and predictors of severe, persistent postprocedural hypotension (PPH) after carotid artery stenting (CAS). Materials and Methods: A total of 146 patients (mean age 72.8 years; 104 men) who underwent 160 CAS procedures using a standardized protocol at 3 vascular centers were retrospectively analyzed. The primary endpoint was postprocedural hypotension, defined as a reduction in systolic blood pressure (SBP) >40 mm Hg from baseline or an SBP of <90 mm Hg sustained for >1 hour after CAS. Potential prognostic factors for postprocedural hypotension were identified and subjected to logistic regression analyses; outcomes are presented as the odds ratios (ORs) with 95% confidence intervals (CIs). Results: PPH developed in 36 (24.7%) patients after 37 (23.1%) CAS procedures. These patients had significantly longer intensive care unit and hospital stays than those who did not develop hypotension (p<0.001). PPH was associated with severe lesion calcification (OR 6.28, 95% CI 1.81 to 21.98, p=0.004) and contrast volume (OR 1.02, 95% CI 1.01 to 1.02, p<0.001). A 4-fold increase in the risk of PPH (OR 4.22, 95% CI 1.38 to 13.33, p=0.012) was found between the embolic protection device most associated with PPH (Angioguard) and the device least associated with PPH (Emboshield NAV6). A similar trend was also observed for the Precise vs Xact stents (OR 6, 95% CI 2.08 to 17.6, p=0.001). Bootstrapped multivariable modeling identified the Precise stent and contrast volume as significant predictors of persistent postprocedural hypotension. Further investigation of the contrast volume revealed associations with sex, severe calcification, arch type, previous coronary artery bypass surgery, and primary stenting, suggesting that the contrast volume reflects the complexity of the procedure. Conclusion: The complexity of the procedure and type of stent may play a role in the development of postprocedural hypotension after CAS.

Bradycardia and Asystole in Patients Undergoing Symptomatic Chronically Occluded Internal Carotid Artery Recanalization

BACKGROUND

Reports have emerged describing the successful endovascular recanalization of the chronically occluded internal carotid artery (COICA). The impact this restoration of flow has on the sensitive carotid sinus baroreceptors has not been previously described. In this manuscript, we present the largest COICA surgical series to date, with a specific focus on perioperative heart rate abnormalities.

METHODS

Patient demographics were obtained, and the COICAs were radiographically classified based on the anatomic distribution of the stenosis and collateral flow. Thirty-six patients had a total of 37 COICA revascularization procedures.

RESULTS

A total of 23 patients had intraprocedural bradycardia during balloon angioplasty. Three patients went into transient asystole during the procedure, and 2 of these patients had symptomatic bradycardia with ischemic cerebral changes, 1 of which required permanent pacemaking. All other patients had immediate resolution of their bradycardia, asystole, and neurologic symptoms immediately following balloon deflation and pharmaceutical management. There was a statistically significant difference in the observed proportion of bradycardic patients among COICA classifications (P = 0.014). There was no statistically significant difference in mean age between patients with bradycardia and those without (aged 63.36 vs. 67.71 years, P = 0.2265).

CONCLUSIONS

Bradycardia associated with angioplasty of the carotid bulb was observed in the majority of patients receiving COICA revascularization. A small percentage of these patients were symptomatic. Our results suggest that carotid sinus baroreceptors remain active while residing in a complete arterial occlusion, and close monitoring is necessary during balloon angioplasty of the proximal COICA.

Cerebral Hemodynamic Variations in the Early Stage after Carotid Artery Stenting in Patients with and without Near Occlusion

BACKGROUND

To evaluate the unclear cerebral hemodynamic variations in patients with and without near occlusion (NO) in hours after carotid artery stenting (CAS) by transcranial Doppler (TCD).

METHODS

Data of 56 patients (11 patients with carotid artery NO and 45 patients with severe stenosis without NO) who underwent unilateral CAS were analyzed. All patients underwent TCD or transcranial color-code Doppler monitoring before CAS and again at one and three hours after the procedure. We compared bilateral middle cerebral artery peak systolic velocity (MCA-PSV), pulsatility index (PI), and blood pressure (BP) data between the two groups.

RESULTS

Ipsilateral MCA-PSV increased relative to baseline in the stenosis group at one hour (97 ± 30 vs. 84 ± 23 cm/s, 16%, P < 0.001) and three hours (96 ± 28 vs. 84 ± 23 cm/s, 15%, P < 0.001) after CAS. Corresponding increases were distinctly higher in the NO group than in the stenosis group at one hour (116 ± 37 vs. 80 ± 29 cm/s, 51%, P < 0.001) and three hours (113 ± 39 vs. 80 ± 29 cm/s, 46%, P = 0.001) after CAS, whereas BP decreased similarly between the two groups. The ipsilateral PI increased postsurgically in both groups, whereas contralateral MCA-PSV was unaltered.

CONCLUSIONS

CAS can induce a significant increase in PSV and PI in ipsilateral MCA within three hours in patients with NO or severe stenosis but absent NO. The increment of ipsilateral MCA-PSV was greater in patients with NO. TCD can facilitate BP control in the early stage after CAS in patients with NO.

Analysis of Hemodynamic Changes in Early Stage after Carotid Stenting by Transcranial Doppler-A Preliminary Study

BACKGROUND

Cerebral hyperperfusion syndrome or hemodynamic instability, caused by the hemodynamic changes, often occur within 6 hr after carotid artery stenting (CAS) The postprocedure cerebral hemodynamic change in the early phase, <6 hr after CAS, is largely unknown. In this study, we evaluated the cerebral hemodynamic changes in patients after CAS using transcranial Doppler (TCD).

METHODS

From January 2013 to July 2014, medical records of 61 patients who underwent CAS were reviewed retrospectively. Among them, 44 patients had TCD examination before CAS, 1-2 and 3-4 hr after CAS. In the TCD examination, middle cerebral artery (MCA) peak systolic velocity (PSV) and pulsatility index (PI) on the ipsilateral and contralateral sides were measured. Blood pressure, MCA PSV, and PI data were collected and analyzed from the 44 patients who had valid TCD examinations.

RESULTS

Blood pressure was 148.4 ± 14.5 mm Hg before CAS: 124.5 ± 13.8 mm Hg 1-2 hr after CAS, and 121.6 ± 12.6 mm Hg 3-4 hr after CAS. On the ipsilateral side, the MCA PSV increased from 85.7 ± 22.8 cm/s before CAS to 101.1 ± 27.1 cm/s (19.9%, P < 0.001) 1-2 hr after CAS, and 99.7 ± 27.0 cm/s (18.2%, P < 0.001) 3-4 hr after CAS. There was no significant difference in MCA PSV between 1-2 and 3-4 hr after CAS (P = 0.200). The PI increased from 0.871 ± 0.167 before CAS to 0.941 ± 0.205 (P = 0.022) 1-2 hr after CAS, and 0.954 ± 0.218 (P = 0.010) 3-4 hr after CAS. On the contralateral side, there was no statistically significant PSV increase in the MCA following CAS.

CONCLUSIONS

CAS may induce a significant increase in PSV and PI in the ipsilateral MCA within 4 hr. The MCA PSV increased significantly higher than that on the contralateral side. The PSV had no significant change between 1-2 and 3-4 hr after CAS.

Complications and Predictors of Hypotension Requiring Vasopressor after Carotid Artery Stenting

A significant controversy exists regarding the clinical impact of hemodynamic depression on major adverse events after carotid artery stenting (CAS). The purpose of this study was to evaluate the incidence, predictors, and clinical significance of hypotension after CAS. A total of 118 cases of carotid artery stenosis were treated with CAS. Hypotension was defined as sustained systolic blood pressure <80 mmHg and requiring intravenous administration of vasopressor to maintain adequate systolic blood pressure after the procedure. Baseline characteristics, procedural characteristics, and periprocedural major adverse events were retrospectively compared between postprocedural hypotension group and non-hypotension group. Morphological and procedural characteristics were not significantly different between the two groups. Periprocedural major adverse events, presence of new ischemic lesions, and number of new ischemic lesions were not significantly different between the two groups (P = 1, P = 0.36, P = 0.68). Hypertension was an independent protective factor (P = 0.037), and use of proximal protection and the distance from carotid bifurcation to maximum stenotic lesion ≤ 10 mm were independent risk factors for developing hypotension after CAS (P = 0.034, P = 0.027). There was no significant relationship between hypotension after CAS and major adverse events in this study. Maintenance of periprocedural adequate cerebral perfusion is thought to be important to prevent ischemic complications due to hypotension after CAS, especially in these cases.

Beneficial effects of prolonged blood pressure control after carotid artery stenting

Objectives

The main purpose of this study was to investigate whether carotid artery stenting (CAS) plus medicine in patients with severe carotid artery stenosis provide a better long-term blood pressure (BP) control compared to other medical treatments alone. The other aim was to explore the correlation between post-CAS hypotension within 6 h and long-term BP reductions after CAS.

Materials and methods

Patients with severe carotid stenosis were recruited either in the CAS group or in the medication group. BPs and the number of classes of antihypertensive agents were recorded at baseline, 6, and 12 months. Extra BP information was collected at 6 h, 3 days, and 1 month after CAS. Univariate and multivariate linear regressions were performed to test the relationship of BP changes among CAS and medication groups after 6 and 12 months of follow-up. Univariate linear regressions were also used to determine the correlations between the mean or maximal systolic BP (SBP) reductions at 6 h and 1 year post-CAS.

Results

In total, 72 members in the CAS group and 82 members in the medication group were recruited. Compared with the medication group, patients in the CAS group had greater BP reductions at 6 and 12 months of follow-up after adjusting for confounding factors (13.56 mmHg at 6 months, P=0.0002; 16.98 mmHg at 12 months, P<0.0001). This study also shows significant positive correlations between the mean or maximal SBP reductions 6 h post-CAS and SBP reductions 1 year post-CAS (β =0.20±0.07, P=0.0067 and β =0.47±0.10, P<0.0001, respectively).

Conclusion

As compared to medical treatment alone, CAS may provide significant beneficial effect on long-term BP control 1 year post-CAS. Furthermore, SBP reductions 6 h post-CAS may predict the SBP reductions 1 year post-CAS.

Critical Care of Brain Reperfusion

Over the last few decades, the management of acute ischemic stroke has undergone significant advancements with the introduction of intravenous thrombolysis and more recently punctuated by the success of endovascular mechanical thrombectomy trials for large vessel occlusion. These advancements have transformed the practice of neurocritical care. In this review, we present a case-based discussion of common brain reperfusion techniques with an emphasis on complication recognition and management. The article encompasses recent evidence-based recommendations as well as some of our own institutional protocols.

Fatal delayed hemodynamic depression after carotid artery stenting

Refractory and fatal hemodynamic depression remarkably occurred eight hours after left carotid artery stenting in a 62-year-old male who had no hemodynamic instability till then; possible contributory factors were pre-existing moderate left ventricular systolic dysfunction and new-onset complete heart block caused by vasopressor-induced sympathetic stimulation in the presence of covert distal conduction system disease.

Dysautonomic responses during percutaneous carotid intervention: principles of physiology and management

Percutaneous carotid artery stenting (CAS) has emerged as a less invasive alternative to carotid endarterectomy for the treatment of carotid atherosclerotic disease. The main risk of CAS is the occurrence of neuro-vascular complications; however, carotid artery stenting-related dysautonomia (CAS-D) (hypertension, hypotension, and bradycardia) is the most frequently reported problem occurring in the periprocedural period. Alterations in autonomic homeostasis result from baroreceptor stimulation, which occurs particularly at the time of balloon inflation in the region of the carotid sinus. The response can be profound enough to induce asystole or even complete cessation of postganglionic sympathetic nerve activity. Frequency and factors predisposing a patient to CAS-D have been investigated in several studies; however, there are significant discrepancies in results among reports. Lack of consistent findings may arise from using different methods and definitions, as well as other factors discussed in detail in this review. Furthermore, a correlation of CAS-D with short and long-term outcomes has been investigated only in small and mostly retrospective studies, explaining why its prognostic significance remains uncertain. In this manuscript, we have focused on risk factors, pathophysiology and management of periprocedural autonomic dysfunction. As there is no standardized approach to the treatment of CAS-D, we present an algorithm for the periprocedural management of patients undergoing CAS. The proposed algorithm was developed based on our procedural experience as well as data from the available literature. The Yale Algorithm was successfully implemented at our institution and we are currently collecting data for short- and long-term safety. © 2014 Wiley Periodicals, Inc.

Incidence and timing of hypotension after transcervical carotid artery stenting: correlation with postoperative complications

OBJECTIVES

To assess the incidence and timing of hypotension after carotid artery stenting (CAS) and its correlation with postoperative complications.

BACKGROUND

CAS-associated postoperative hypotension has been linked to surgical morbidity and mortality, especially to stroke and cardiac complications.

METHODS

Ninety-seven consecutive patients undergoing transcervical CAS were monitored for at least 12 hr after operation. Hypotension was defined as systolic blood pressure < 90 mm Hg. Patients were divided into three groups: normal blood pressure and early (≤6 hr) and late (>6 hr) hypotension. Complications were recorded.

RESULTS

Hypotension occurred in 34% of the patients (early hypotension in 63% of them). Hypotension was recorded in 21.6% of patients during surgery and in 21.6%, 15.5%, and 1.0% at 6, 12, and 24 hr postoperatively. Bradycardia occurred in 26.8% during operation and in 25.8%, 13.4%, and 10.3% at 6, 12, and 24 hr after surgery. Intraoperative bradycardia (P = 0.01) and hypotension (P = 0.02) were predictors of postoperative hypotension. The overall rate of complications was 5% without differences between the study groups. The mean length of stay was 3, 3.6, and 2.8 days in the normotensive, early hypotension, and late hypotension groups, respectively.

CONCLUSIONS

Most postoperative hypotension episodes occurred within the first 6 hr, and more than one-third between the 6 and 12 hr post-procedure. All patients with late hypotension were asymptomatic. There was no difference in complications between the study groups. In patients undergoing ambulatory CAS, hemodynamic monitoring in the postoperative period is particularly important during the first 12 hr.

Periprocedural hemodynamic depression is associated with a higher number of new ischemic brain lesions after stenting in the International Carotid Stenting Study-MRI Substudy

BACKGROUND AND PURPOSE

Carotid artery stenting (CAS) is associated with a higher risk of both hemodynamic depression and new ischemic brain lesions on diffusion-weighted imaging than carotid endarterectomy (CEA). We assessed whether the occurrence of hemodynamic depression is associated with these lesions in patients with symptomatic carotid stenosis treated by CAS or CEA in the randomized International Carotid Stenting Study (ICSS)-MRI substudy.

METHODS

The number and total volume of new ischemic lesions on diffusion-weighted imaging 1 to 3 days after CAS or CEA was measured in the ICSS-MRI substudy. Hemodynamic depression was defined as periprocedural bradycardia, asystole, or hypotension requiring treatment. The number of new ischemic lesions was the primary outcome measure. We calculated risk ratios and 95% confidence intervals per treatment with Poisson regression comparing the number of lesions in patients with or without hemodynamic depression.

RESULTS

A total of 229 patients were included (122 allocated CAS; 107 CEA). After CAS, patients with hemodynamic depression had a mean of 13 new diffusion-weighted imaging lesions, compared with a mean of 4 in those without hemodynamic depression (risk ratio, 3.36; 95% confidence interval, 1.73-6.50). The number of lesions after CEA was too small for reliable analysis. Lesion volumes did not differ between patients with or without hemodynamic depression.

CONCLUSIONS

In patients treated by CAS, periprocedural hemodynamic depression is associated with an excess of new ischemic lesions on diffusion-weighted imaging. The findings support the hypothesis that hypoperfusion increases the susceptibility of the brain to embolism.

CLINICAL TRIAL REGISTRATION

URL: http://www.controlled-trials.com. Unique identifier: ISRCTN25337470.

Incidence of hemodynamic depression after carotid artery stenting using different self-expandable stent types

The rates of hemodynamic depression (HD) and thromboembolism were compared in 95 carotid artery stenting (CAS) procedures performed in 87 patients with severe carotid artery stenosis using self-expandable braided Elgiloy stents (Wallstent) in 52 and slotted-tube Nitinol stents (Precise) in 43 procedures. The blood pressure, pulse rate, and neurological signs were recorded at short intervals during and after CAS. All patients underwent diffusion-weighted magnetic resonance imaging within 5 days after the procedure. The incidences of hypotension, bradycardia, and both were 17.9%, 3.2%, and 11.6%, respectively. The rate of postprocedural HD was 23.1% with Wallstent and 44.2% with Precise; the difference was significant (p = 0.025). No patient manifested major cardiovascular disease after CAS. Diffusion-weighted magnetic resonance imaging revealed thromboembolism after 26.9% and 34.9% of Wallstent and Precise stent placement procedures, respectively; the difference was not significant. The type of self-expandable stent placed may affect the risk of procedural HD in patients undergoing CAS. Postprocedural HD was resolved successfully by the administration of vasopressors and by withholding antihypertensive agents.

Effects of Carotid Endarterectomy or Stenting on Hemodynamic Complications in the International Carotid Stenting Study: A Randomized Comparison

Background

Carotid endarterectomy and carotid artery stenting are frequently complicated by hemodynamic instability.

Aims

The study aims to compare the incidence of hemodynamic complications between carotid artery stenting and carotid endarterectomy in the International Carotid Stenting Study (ISRCTN25337470).

Methods

Patients with symptomatic carotid stenosis were randomly allocated to carotid artery stenting or carotid endarterectomy. The occurrence of peri-procedural hemodynamic depression (severe bradycardia, asystole, or hypotension requiring treatment) and hypertension requiring treatment was assessed in a per-protocol analysis. We compared the rate of hemodynamic complications, determined independent predictors thereof, and assessed their relation with the composite outcome of all-cause death, stroke, and myocardial infarction within 30 days of treatment.

Results

A number of 766 carotid artery stenting and 819 carotid endarterectomy patients had a single completed intervention. Hemodynamic depression occurred in 13·8% after carotid artery stenting and in 7·2% after carotid endarterectomy (relative risk 1·9, 95% confidence interval 1·4–2·6, P < 0·0001). Hypertension requiring treatment occurred less often after carotid artery stenting than after carotid endarterectomy (relative risk 0·2, 95% confidence interval, 0·1–0·4, P < 0·0001). In carotid artery stenting patients, a history of cardiac failure was the strongest independent predictor of hemodynamic depression (relative risk 2·4, 95% confidence interval 1·3–4·8, P = 0·009). There was no statistically significant association between hemodynamic complications and the occurrence of the composite outcome.

Conclusion

Hemodynamic depression occurs more often after carotid artery stenting and severe hypertension more often after carotid endarterectomy, but these complications are not responsible for the excess of major perioperative events after carotid artery stenting.

Carotid artery stenting without angioplasty and cerebral protection: a single-center experience with up to 7 years' follow-up

BACKGROUND AND PURPOSE

The use of cerebral protection during CAS in the treatment of carotid artery disease is matter of controversy. The purpose of this study was to evaluate the outcome of CASWBAP in a large cohort of patients, with ≤7 years' follow-up.

MATERIALS AND METHODS

Two hundred thirty-six patients with 255 symptomatic carotid stenoses and/or with high-risk-morphology plaques of >50% and asymptomatic plaques of >70% were prospectively identified. Patients underwent neurologic and carotid US examination before the procedure and during follow-up at 1, 3, 6, and 12 months and annually thereafter. Plain films of the neck were obtained immediately after the procedure and then at 1 and 3 months.

RESULTS

Technical success was achieved in 253/255 (99%) patients. Primary stent placement was successful in 248/253 (98%) patients. Neurologic periprocedural complications within 30 days included 1 (0.4%) nondisabling stroke, 1 (0.4%) disabling stroke, 11 (4.3%) TIAs, and 1 (0.4%) death. The mean duration of follow-up was 23 ± 1.4 months (range, 3-84 months). During the follow-up period, there were 9 additional deaths (7 unrelated to the carotid disease and 2 stroke-related) and 2 strokes (in other vascular territories). The degree of stenosis decreased from a mean of 82% before the procedure to a mean of 30% immediately after. During follow-up, 38 (14.8%) angioplasties were performed due to restenosis in 19 (7.4%) patients, lack of stent expansion in 14 (5.4%), or both in 5 (1.9%).

CONCLUSIONS

CASWBAP is effective and safe with a low incidence of periprocedural complications, providing satisfactory long-term clinical results.

Prolonged carotid sinus reflex is a risk factor for contrast-induced nephropathy following carotid artery stenting

BACKGROUND AND PURPOSE

Although many studies have demonstrated that CIN is associated with in-hospital and long-term mortality, the incidence of CIN following CAS is unclear. We investigated the incidence of CIN, defined as an increase from a baseline creatinine value of at least 0.5 mg/dL or 25% within 72 hours of contrast administration, and we also examined renal function in the late phase after CAS.

MATERIALS AND METHODS

We examined 80 patients who underwent CAS between April 2005 and December 2009. Clinical background, laboratory data, contrast volume, and clinical course were collected and analyzed.

RESULTS

The incidence of CIN was 8.8% (7/80), and no patients required hemodialysis. In the group that developed CIN, prolonged CSR after CAS was found in 57.1% (4/7) of cases; this incidence differed significantly (P = .001) from that in the group without development of CIN. Neither preoperative renal function, contrast volume, nor history was related to the incidence of CIN, while on multivariate analysis, prolonged CSR was found to be an independent risk factor for CIN. The incidence of elevation in creatinine values at 6 months after CAS was 8.2% (6/73). All patients who developed delayed renal impairment had pre-existing CKD; this finding differed significantly (P = .04) from that in the group without development of delayed renal impairment.

CONCLUSIONS

Because patients who develop prolonged CSR after CAS are at increased risk of perioperative major adverse clinical events including CIN, patients at high risk for this condition should be carefully managed to prevent increased morbidity and mortality.

Simultaneous bilateral carotid stenting in high-risk patients

BACKGROUND AND PURPOSE

The safety and efficacy of SBCAS have not been evaluated in detail. The purpose of our study was to evaluate the outcome after SBCAS in high-risk patients compared with unilateral stent placement.

MATERIALS AND METHODS

Between March 2002 and October 2008, a total of 205 consecutive high-risk patients underwent CAS at our institution. Of these patients, 30 (14.6%) underwent SBCAS (n = 24) and staged SBCAS (n = 6). Patients who underwent unilateral CAS (n = 175) during the same period served as controls. The stroke risk factors, procedural results, and outcome at 30 days and 6 months, as well as the restenosis rate at 6 months, were compared by using either the chi(2) test or the Kruskal-Wallis equality-of-populations rank test.

RESULTS

Our data revealed no significant differences in the stroke risk factors between the SBCAS and the control group. HPS occurred more commonly in SBCAS (ie, 16.7%, 4/24) compared with 2.9% (5/175) in the control group (P = .014). However, there was no statistical significance between 2 groups in the event rate of stroke (minor and/or major stroke), death, or restenosis at 6 months.

CONCLUSIONS

There was no significant difference in outcome at 6 months following stent placement between SBCAS and unilateral CAS in the high-risk patient group, even though HPS occurred more commonly after SBCAS.