Comparative Outcomes of Carotid Artery Stent Placement and Carotid Endarterectomy in Patients with Chronic Kidney Disease and End-Stage Renal Disease

Multi-center experience with intravascular lithotripsy for treatment of severe calcification during transcarotid artery revascularization for high-risk patients

OBJECTIVE

Transcarotid artery revascularization (TCAR) offers a safe alternative to carotid endarterectomy (CEA), but severe calcification is currently considered a contraindication in carotid artery stenting. This study aims to describe the safety and effectiveness of TCAR with intravascular lithotripsy (IVL) in patients with traditionally prohibitive calcific disease.

METHODS

All consecutive patients who underwent TCAR+IVL from 2018-2022 at nine institutions were identified. IVL was combined with pre-dilatation angioplasty to treat calcified vessels before stent deployment. The primary outcome was a new ipsilateral stroke within 30 days. Secondary outcomes included any new ipsilateral neurologic event (stroke/transient ischemic attack [TIA]) at 30 days, technical success, and <30% residual stenosis.

RESULTS

Fifty-eight patients (62% male; mean age, 78 ± 6.6 years) underwent TCAR+IVL, with 22 (38%) for symptomatic disease. Fifty-seven patients (98%) met high-risk anatomical or physiologic criteria for CEA. Forty-seven patients had severely calcific lesions. Fourteen patients (30%) had isolated eccentric plaque, 20 patients (43%) had isolated circumferential plaque, and 13 (27%) had eccentric and circumferential calcification. Mean procedure and flow reversal times were 87 ± 27 minutes and 25 ± 14 minutes. The median number of lithotripsy pulses per case was 90 (range, 30-330), and mean contrast usage was 29 mL. No patients had electroencephalogram changes or new deficits observed intraoperatively. Technical success was achieved in 100% of cases, with 98% having <30% residual stenosis on completion angiography. One patient had an in-hospital post-procedural stroke (1.72%). Four patients total had any new ipsilateral neurologic event (stroke/TIA) within 30 days for an overall rate of 6.8%. One TIA and one stroke occurred during the index hospitalization, and two TIAs occurred after discharge. Preoperative mean stenosis in patients with any postoperative neurologic event was 93% (vs 86% in non-stroke/TIA patients; P = .32), and chronic renal insufficiency was higher in patients who had a new neurologic event (75% vs 17%; P = .005). No differences were observed in calcium, procedural, or patient characteristics between the two groups. The mean follow-up was 132 days (range, 19-520 days). Three stents developed recurrent stenosis (5%) on follow-up duplex; the remainder were patent without issue. There were no reported interventions for recurrent stenosis during the study period.

CONCLUSIONS

IVL sufficiently remodels calcified carotid arteries to facilitate TCAR effectively in patients with traditionally prohibitive calcific disease. One patient (1.7%) suffered a stroke within 30 days, although four patients (6.8%) sustained any new neurological event (stroke/TIA). These results raise concerns about the risks of TCAR+IVL and whether it is an appropriate strategy for patients who could potentially undergo CEA.

Outcomes of carotid revascularization stratified by procedure in patients with an estimated glomerular filtration rate of <30 and dialysis patients

OBJECTIVE

Renal failure is a predictor of adverse outcomes in carotid revascularization. There has been debate regarding the benefit of revascularization in patients with severe chronic kidney disease or on dialysis.

METHODS

Patients in the Vascular Quality Initiative undergoing transcarotid artery revascularization (TCAR), transfemoral carotid artery stenting (tfCAS), or CEA between 2016 and 2023 with an estimated glomerular filtration rate (eGFR) of <30 mL/min/1.73 m2 or on dialysis were included. Patients were divided into cohorts based on procedure. Additional analyses were performed for patients on dialysis only and by symptomatology. Primary outcomes were perioperative stroke/death/myocardial infarction (MI) (SDM). Secondary outcomes included perioperative death, stroke, MI, cranial nerve injury, and stroke/death. Inverse probability of treatment weighting was performed based on treatment assignment to TCAR, tfCAS, and CEA patients and adjusted for demographics, comorbidities, and preoperative symptoms. The χ2 test and multivariable logistic regression analysis were used to evaluate the association of procedure with perioperative outcomes in the weighted cohort. Five-year survival was evaluated using Kaplan-Meier and weighted Cox regression.

RESULTS

In the weighted cohort, 13,851 patients with an eGFR of <30 (2506 on dialysis) underwent TCAR (3639; 704 on dialysis), tfCAS (1975; 393 on dialysis), or CEA (8237; 1409 on dialysis) during the study period. Compared with TCAR, CEA had higher odds of SDM (2.8% vs 3.6%; adjusted odds ratio [aOR], 1.27; 95% confidence interval [CI], 1.00-1.61; P = .049), and MI (0.7% vs 1.5%; aOR, 2.00; 95% CI, 1.31-3.05; P = .001). Compared with TCAR, rates of SDM (2.8% vs 5.8%), stroke (1.2% vs 2.6%), and death (0.9% vs 2.4%) were all higher for tfCAS. In asymptomatic patients CEA patients had higher odds of MI (0.7% vs 1.3%; aOR, 1.85; 95% CI, 1.15-2.97; P = .011) and cranial nerve injury (0.3% vs 1.9%; aOR, 7.23; 95% CI, 3.28-15.9; P < .001). Like in the primary analysis, asymptomatic tfCAS patients demonstrated higher odds of death and stroke/death. Symptomatic CEA patients demonstrated no difference in stroke, death, or stroke/death. Although tfCAS patients demonstrated higher odds of death, stroke, MI, stroke/death, and SDM. In both groups, the 5-year survival was similar for TCAR and CEA (eGFR <30, 75.1% vs 74.2%; aHR, 1.06; P = .3) and lower for tfCAS (eGFR <30, 75.1% vs 70.4%; aHR, 1.44; P < .001).

CONCLUSIONS

CEA and TCAR had similar odds of stroke and death and are both a reasonable choice in this population; however, TCAR may be better in patients with an increased risk of MI. Additionally, tfCAS patients were more likely to have worse outcomes after weighting for symptom status. Finally, although patients with a reduced eGFR have worse outcomes than their healthy peers, this analysis shows that the majority of patients survive long enough to benefit from the potential stroke risk reduction provided by all revascularization procedures.

Carotid Endarterectomy Should Not Be Recommended to End-Stage Kidney Disease Patients with Asymptomatic Carotid Artery Disease

BACKGROUND

Carotid endarterectomy (CEA) for asymptomatic carotid artery disease is advised for patients with low perioperative stroke risk and life expectancy of 3-5 years. We sought to explore the role of risk stratification and postoperative medical management in identifying appropriate asymptomatic candidates for CEA in the end-stage kidney disease (ESKD) population.

METHODS

We identified ESKD patients on dialysis from the United States Renal Data System that underwent CEA (2008-2014) for asymptomatic carotid artery disease. We used the Liu comorbidity index as well as a novel risk prediction model based on Cox proportional hazards model to stratify patients. The primary outcome evaluated was 3-year survival, and Kaplan-Meier methods were used to generate survival estimates. We further conducted a subanalysis of patients with Medicare part D data to determine postoperative usage of the following medications: statins, antiplatelets, and antihypertensives. We evaluated the association of medication utilization and 3-year survival using Kaplan-Meier methods and Cox proportional hazards modeling.

RESULTS

We analyzed 1,813 patients meeting inclusion criteria. The population was predominantly older (mean age 70.2 ± 9.1), White (84.8%), and had a high prevalence of cardiovascular comorbidities, such as hypertension (90.7%), diabetes (62.5%), and congestive heart failure (35.4%). Among the entire cohort, 23.0% had a Liu comorbidity index ≤8, 35.0% had index 9-12, and 42.0% had index >12. Increasing Liu comorbidity index was associated with worse survival (P < 0.01); however, even the group with Liu index ≤8 had poor 3-year survival of 58.8% (53.9-63.4). The Cox proportional hazards model identified variables for inclusion in the risk model such as age >80 (adjusted hazard ratio [aHR] = 2.49, 95% confidence interval [CI] [1.87-3.33], P < 0.001), congestive heart failure (aHR = 1.31, 95% CI [1.14-1.51], P < 0.001), and Liu comorbidity index >12(aHR = 1.89, 95% CI [1.56-2.28], P < 0.001). The risk score generated ranged from 0 to 6.5, and patients were divided into 3 groups: score ≤2 (43.4%), 2-4 (41.2%), and >4 (15.4%). Increasing risk score was associated with worse survival (P < 0.01) but even the "low-risk" group had 3-year survival of 58.5% (54.9-61.9). Subanalysis of the 1,249 (68.8% of total) patients with part D data found that statins and calcium channel blocker use was associated with improved survival, although observed rates for patients on drug were still low.

CONCLUSIONS

The overall long-term survival of ESKD patients undergoing CEA for asymptomatic carotid artery disease is low. Risk stratification and analysis of postoperative medical management did not identify a subgroup of patients with adequate 3-year survival. Hence, the preventive benefits of CEA are not realized in these patients.

Kidney disease and stroke: epidemiology and potential mechanisms of susceptibility

Patients with chronic kidney disease (CKD) have an increased risk of both ischaemic and haemorrhagic stroke compared with the general population. Both acute and chronic kidney impairment are independently associated with poor outcome after the onset of a stroke, after adjustment for confounders. End-stage kidney disease (ESKD) is associated with a 7- and 9-fold increased incidence of both ischaemic and haemorrhagic strokes, respectively, poorer neurological outcome and a 3-fold higher mortality. Acute kidney injury (AKI) occurs in 12% of patients with stroke and is associated with a 4-fold increased mortality and unfavourable functional outcome. CKD patients seem to have less access to revascularisation techniques like thrombolysis and thrombectomy despite their poorer prognosis. Even if CKD patients could benefit from these specific treatments in acute ischaemic stroke, their prognosis remains poor. After thrombolysis, CKD is associated with a 40% increased risk of intracerebral haemorrhage (ICH), a 20% increase in mortality and poorer functional neurological outcomes. After thrombectomy, CKD is not associated with ICH but is still associated with increased mortality, and AKI with unfavourable outcome and mortality. The beneficial impact of gliflozins on the prevention of stroke is still uncertain. Non-traditional risk factors of stroke, like uraemic toxins, can lead to chronic cerebrovascular disease predisposing to stroke in CKD, notably through an increase in the blood-brain barrier permeability and impaired coagulation and thrombosis mechanisms. Preclinical and clinical studies are needed to specifically assess the impact of these non-traditional risk factors on stroke incidence and outcomes, aiming to optimize and identify potential therapeutic targets.

Fate of Hemodialysis Patients Undergoing Transcarotid Revascularization

INTRODUCTION

Carotid revascularization in patients with end-stage renal disease (ESRD) continues to be a controversial topic, as life expectancy is poor, thus, preventing the recouperation of cumulative stroke-risk reduction in the postoperative period. We performed this primarily descriptive analysis of the results of transcarotid revascularization (TCAR) in renal failure patients.

METHODS

A retrospective review of two independent carotid revascularization databases maintained at two large health systems were performed to capture all consecutive TCAR procedures. Patients were classified as either (1) ESRD or (2) preserved renal function (PRF) and compared with standard univariate techniques, where appropriate.

RESULTS

From December 2015 to April 2022, 851 consecutive TCARs were attempted at our participating facilities. Of these, 27 were performed in ESRD patients (all hemodialysis). These patients were younger and presented with a higher Charlson Comorbidity Index. The incidence of a high anatomic risk criterion as defined for the Centers for Medicare and Medicaid Services (CMS) were similar between groups, as was the incidence of a symptomatic carotid lesion. There were no differences between the groups in terms of intraoperative characteristics and the postoperative medication management were grossly similar by renal function. In the 30-day perioperative period, there were no stroke, death, or myocardial infarction in the 27 ESRD patients treated with TCAR. The mean duration of follow-up in the ESRD cohort was 15.0 months. During this time, there was no ipsilateral stroke events, one contralateral stroke, and one MI. All 27 carotid stents remained patent during this period. Six patients perished after TCAR at a mean interval of 12.2 months after TCAR.

CONCLUSION

Survival is poor after carotid revascularization via the TCAR technique on intermediate follow-up. Careful patient selection is required to identify those who will survive to collect on the cumulative stroke-risk reduction afforded by carotid intervention.

Narrative Review of Carotid disease and the kidney

Patients with chronic kidney disease (CKD) have an increased cardiovascular (CV) risk that is only in part explained by established risk factors. Carotid arteriosclerosis and atherosclerosis are increased in CKD, play a role in the causation of CV disease in these patients and can affect the progression of renal disease. The arterial stiffening process is evident even in CKD patients with a very mild reduction of glomerular filtration rate (GFR) whereas arterial thickening is evident in more advanced stages. Possible mechanisms include functional and structural alterations of the arterial wall. Arterial stiffness can mediate the effect of CKD on target organs (i.e., brain, kidney and heart). In this review we discuss the arterial phenotype of patients with CKD. This is characterized by increased common carotid artery stiffness and outward remodeling (enlargement and thickening of the arterial wall) and a normal/reduced stiffness paired with an inward remodeling (narrowing of the arterial wall) of muscular arteries. We also discuss the consequences of carotid dysfunction, including the involvement of large elastic arteries stiffness on ventricular-vascular coupling, the mechanisms linking carotid stiffening and increased cardio- and cerebrovascular risk in CKD patients, and the therapeutic options to improve carotid function.

Perioperative outcomes for carotid revascularization on asymptomatic dialysis-dependent patients meet Society for Vascular Society guidelines

OBJECTIVE

The current Society for Vascular Surgery practice guidelines recommend carotid revascularization for asymptomatic disease in patients with at least a 3-year life expectancy and stenosis >60% when the expected perioperative stroke and death rate is <3%. Based on this recommendation, it was previously determined that asymptomatic patients who require dialysis would not meet the perioperative stroke and death thresholds nor the long-term survival benchmarks to justify carotid surgery. To determine whether carotid surgery for patients requiring dialysis is appropriate, the present study compared the perioperative outcomes after carotid revascularization for dialysis-dependent patients relative to nondialysis patients in a contemporary, national cohort.

METHODS

The targeted vascular module from the American College of Surgeons National Surgical Quality Improvement Program was queried to identify patients who undergone carotid endarterectomy or carotid artery stenting for asymptomatic carotid disease from 2011 to 2018. The cohort was categorized as requiring or not requiring dialysis. The primary 30-day outcomes included mortality and the composite of stroke/death and stroke/death/myocardial infarction (MI). Univariate analyses were performed using the Fisher exact test and Wilcoxon rank sum test. Multivariable analyses were used to assess the independent associations of the estimated glomerular filtration rate and dialysis dependence with the stroke/death rate.

RESULTS

A total of 17,579 patients met the inclusion criteria. Of these patients, 226 (1.3%) required dialysis at revascularization. No difference was found in the degree of severe stenosis (80%-99%) demonstrated by 69% of the dialysis cohort and 72% of the nondialysis cohort (P = .9). Of the dialysis and nondialysis cohorts, 5% and 3.6% underwent carotid artery stenting (P = .3). The dialysis-dependent patients were younger (68 vs 71 years; P < .001) and were more likely to have insulin-dependent diabetes (47% vs 12%; P < .001), congestive heart failure (8.4% vs 1.4%; P < .001), and severe chronic obstructive pulmonary disease (15% vs 10%; P = .03). In the dialysis and nondialysis cohort, 2 (0.9%) and 88 (0.5%) patients died (P = .3); 4 (1.8%) and 247 (1.4%) experienced strokes (P = .6); and 3 (1.3%) and 185 (1.1%) patients experienced MI (P = .5), respectively. The composite outcomes of stroke/death and stroke/death/MI was 2.2% (n = 5) and 1.8% (n = 319; P = .6) and 3.5% (n = 8) and 2.8% (n = 479; P = .4) in the dialysis and nondialysis cohorts, respectively. After multivariable analysis, neither the estimated glomerular filtration rate (adjusted odds ratio, 1.0; 95% confidence interval, 1.00-1.01; P = .26) nor dialysis dependence (adjusted odds ratio, 0.21; 95% confidence interval, 0.03-1.57; P = .13) was independently associated with the composite outcome of stroke/death.

CONCLUSIONS

The 30-day carotid revascularization outcomes for asymptomatic disease in dialysis-dependent patients met the Society for Vascular Surgery guidelines in this national cohort and might be better than previously surmised. Hence, vascular surgeons could consider carotid revascularization for select dialysis-dependent patients with the appropriate expected longevity and perioperative risk.

Carotid intima-media thickness relative to cognitive impairment in dialysis patients, and their relationship with brain volume and cerebral small vessel disease

Background:

Carotid intima–media thickness (cIMT) is considered a risk factor for and predictor of cerebrovascular disease. In this study, we explored the contribution of cIMT to cognitive impairment (CI) in dialysis patients and the role of cerebral small vascular disease (CSVD) and brain atrophy in this process.

Methods:

Cognitive function was assessed using a comprehensive cognitive test battery. CSVD and brain volume were assessed by magnetic resonance imaging, and cIMT was measured by ultrasonography. Multivariable analysis and mediation were used to explore the relevant relationships among cIMT, CI, CSVD and brain volume.

Results:

Seventy-three dialysis patients were enrolled. Approximately 54.8% were diagnosed with increased cIMT. The increased cIMT group was older and had lower serum albumin and creatinine levels than the normal cIMT group. There was no difference in the CSVD prevalence between the different cIMT groups. Patients in the normal, unilaterally and bilaterally increased cIMT subgroups demonstrated a gradual decrease in brain-matter volume and degenerate cognitive function. cIMT was related to cognitive function and gray-/white-matter volume. Increased cIMT was associated with a significantly increased risk of a reduced Mini Mental State Examination/Montreal Cognitive Assessment score and Trail A/B time delay. Mediation analysis showed that CI was mediated by brain-matter volume but not by CSVD.

Conclusion:

Increased cIMT was an independent risk factor for impairment of global cognitive function, memory, and executive function. The impact of cIMT on cognition was not induced by CSVD but by brain atrophy. cIMT may be a useful tool for screening patients at high risk of CI in the dialysis population.

Long-term Clinical Outcomes of Elective Carotid Artery Stenting in Patients Undergoing Maintenance Hemodialysis

Objective Carotid artery stenting (CAS) in patients undergoing maintenance hemodialysis is characterized by high complication rates. These patients are excluded from clinical trials of CAS. The purpose of our retrospective study was to investigate the long-term clinical outcomes of CAS in patients undergoing maintenance hemodialysis. Methods CAS was performed under local anesthesia. The technical success rate, periprocedural complications, 30-day major vascular event rate (stroke, myocardial infarction, and/or death), 3-month morbidity and mortality rates, and 5-year survival probability were investigated. Patients Nineteen patients undergoing maintenance hemodialysis were identified. Results The mean age of the patients was 69 years. Periprocedural complications occurred in two patients (confusion following CAS in one and transient hemiparesis in the other). Complete neurological recovery was achieved in both patients. No major cardiovascular events occurred within 30 days after CAS. Asymptomatic intracranial hemorrhage only occurred in one patient, and seven patients died during the follow-up period at a mean of 3.5 years after the procedure (range, 6 months to 8 years). No permanent neurologic deficit remained in the patient with intracranial hemorrhage. The causes of death were cardiovascular disease (n = 4), cancer (n = 2), and pneumonia (n = 1). No patients died of stroke. The 5-year survival probability in patients undergoing maintenance hemodialysis was 57%. Conclusion CAS in maintenance hemodialysis patients may be feasible and effective for the prevention of stroke with proper case selection, appropriate technique and strict perioperative management. The most common causes of death during the follow-up of maintenance hemodialysis patients were diseases other than stroke.

Primary Prevention of Stroke in Chronic Kidney Disease Patients: A Scientific Update

BACKGROUND

Although chronic kidney disease (CKD) is an independent risk factor for stroke, official recommendations for the primary prevention of stroke in CKD are generally lacking.

SUMMARY

We searched PubMed and ISI Web of Science for randomised controlled trials, observational studies, reviews, meta-analyses and guidelines referring to measures of stroke prevention or to the treatment of stroke-associated risk factors (cardiovascular disease in general and atrial fibrillation (AF), arterial hypertension or carotid artery disease in particular) among the CKD population. The use of oral anticoagulation in AF appears safe in non-end stage CKD, but it should be individualized and preferably based on thromboembolic and bleeding stratification algorithms. Non-vitamin K antagonist oral anticoagulants with definite dose adjustment are generally preferred over vitamin K antagonists in mild and moderate CKD and their indications have started being extended to severe CKD and dialysis also. Aspirin, but not clopidogrel, has limited indications for reducing the risk for atherothrombotic events in CKD due to its increased bleeding risk. Carotid endarterectomy has shown promising results for stroke risk reduction in CKD patients with high-grade symptomatic carotid stenosis. The medical treatment of arterial hypertension in CKD often fails to efficiently lower blood pressure values, but recent data regarding the use of interventional procedures such as renal denervation, baroreflex activation therapy or renal artery stenting are encouraging. Key Messages: In the absence of clear guidelines and protocols, primary prevention of stroke in CKD patients remains a subtle art in the hands of the clinicians. Nevertheless, refraining CKD patients from standard therapies often worsens their prognosis.