The Risk of Carotid Endarterectomy in Patients with Chronic Renal Insufficiency

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.

Perioperative and long-term impact of chronic kidney disease on carotid artery interventions

OBJECTIVE

Chronic kidney disease (CKD) increases morbidity and mortality after vascular procedures and adversely affects late survival of patients. The presence of CKD also confers increased risk of stroke in patients with asymptomatic carotid stenosis. Patients undergoing carotid intervention in the Vascular Study Group of New England database were stratified by CKD status referable to periprocedural and late outcomes.

METHODS

All carotid artery stenting and carotid endarterectomies (CEAs) performed from 2003 to 2013 were stratified by CKD severity as mild (estimated glomerular filtration rate [eGFR] >60 mL/min/1.73 m²), moderate (eGFR 30-59), and severe (eGFR <30). The impact of CKD on outcomes of carotid procedures was evaluated using univariate and multivariate methods.

RESULTS

Of 12,568 patients identified, 11,746 (93%) underwent CEA and 822 (7%) underwent carotid artery stenting. Procedures were performed for symptomatic disease in 40%. CKD severity was mild in 58%, moderate in 35%, and severe in 7%. The 30-day stroke rate was very low across all CKD groups (1.76% mild vs 1.84% moderate and 1.34% severe; P = .009). The 30-day mortality increased with worsening renal function (0.4% mild vs 0.9% moderate and 0.9% severe; P = .01). Independent predictors of 30-day stroke or death included American Society of Anesthesiologists (ASA) class 4 or 5 (odds ratio, 2.3; 95% confidence interval [CI], 1.5-3.4; P = .0001). Multivariable Cox hazards regression showed that severe CKD (hazard ratio [HR], 1.8; 95% CI, 1.3-2.6), ASA class 4 or 5 (HR, 1.7; 95% CI, 1.3-2.2), preoperative cortical symptoms (HR, 1.5; 95% CI, 1.2-1.8), history of diabetes (HR, 1.4; 95% CI, 1.1-1.7), and age (HR, 1.03/y; 95% CI, 1.02-1.04) independently (all P < .01) predicted neurologic events or death at median follow-up of 12.7 months (interquartile range, 10.3-15.2 months). CKD did not increase the risk of neurologic events at 1-year follow-up. Predictors (P < .05) of late death included moderate CKD (HR, 1.3; 95% CI, 1.01-1.7), severe CKD (HR, 2.2; 95% CI, 1.6-2.9), ASA class 4 or 5 (HR, 1.6; 95% CI, 1.2-2.0), history of diabetes (HR, 1.4; 95% CI, 1.2-1.7), chronic obstructive pulmonary disease (HR, 1.4; 95% CI, 1.1-1.8), and cortical symptoms (HR, 1.3; 95% CI, 1.05-1.6). The 1-, 5-, and 10-year survival rates decreased with worsening renal function (log-rank test, P < .001), but patients with severe CKD maintained a 71% survival at 5 years.

CONCLUSIONS

CKD severity increases risk of perioperative mortality as well as late mortality. Patients with CKD benefit from stroke-free survival especially after CEA. Unlike patients with peripheral arterial occlusive disease, for whom severe CKD reduces median survival to ∼2.5 years, patients with CKD and carotid disease exhibit much longer survival. This suggests that carotid interventions have utility in carefully selected patients with moderate and severe CKD, particularly in symptomatic disease.

A contemporary evaluation of carotid endarterectomy outcomes in patients with chronic kidney disease in the United States

Objectives Chronic kidney disease (CKD) has been identified as a significant risk factor for poor post-surgical outcomes. This study was designed to provide a contemporary analysis of carotid endarterectomy (CEA) outcomes in patients with CKD, end-stage renal disease (ESRD), and normal renal function (NF). Methods The Nationwide Inpatient Sample data 2006-2012 was queried to select patients aging 40 years old and above who underwent CEA during two days after admission and had a diagnosis of ESRD on long-term hemodialysis, patients with non-dialysis-dependent CKD, or NF. Patients with acute renal failure were excluded. We subsequently compared procedure outcomes and hospital resource utilization in these patients. Results Totally 573,723 CEA procedures were estimated: 4801 (ESRD)' 32,988 (CKD)' and 535,934 (NF). Mean age was 71.0 years, 57.7% were males, and 73.7% were white. Overall hospital mortality was 0.20%: 0.69% (ESRD), 0.35% (CKD), and 0.19% (NF), p < 0.0005 between groups. The overall stroke rate was 1.6%: 1.8% (ESRD), 2.0% (CKD), and 1.6% (NF). Comparing NF to CKD there was a significant difference: p < 0.0001. For CKD patients, compared to NF patients, there was an increased risk in cardiac complications (odds ratio = 1.2; 95% CI 1.15-1.32), respiratory complications (odds ratio = 1.2; 95% CI 1.15-1.32), and stroke (odds ratio = 1.1; 95% CI 1.04-1.23). For ESRD patients compared to NF patients there was an increased risk in respiratory complications (odds ratio = 1.3; 95% CI 1.08-1.47) and sepsis (odds ratio = 4.4; 95% CI 3.23-5.94). Mean length of stay and cost were: 2.8 d and $13,903 (ESRD), 2.2 d and $12,057 (CKD), and 1.8 d and $10,130 (NF), all p < 0.0001. Conclusions Patients with ESRD undergoing CEA had an increased risk of respiratory and septic complications, but not a higher risk of stroke compared to patients with normal renal function. The greatest risks of postoperative stroke, respiratory, and cardiac complications were found in patients with CKD. A diagnosis of ESRD and CKD were both found to significantly increase hospital mortality, length of stay and cost. Where clinicians typically consider ESRD patients the highest risk for CEA, further consideration should be given to patients with CKD not yet on dialysis as they had the higher risk of cardiac complications and stroke compared to the others evaluated.

Rates and predictors of 5-year survival in a national cohort of asymptomatic elderly patients undergoing carotid revascularization

BACKGROUND

Current American Heart Association guidelines recommend carotid revascularization for asymptomatic patients on the basis of life expectancy.

OBJECTIVE

To determine the rates and predictors of 5-year survival in elderly patients with asymptomatic carotid artery stenosis who underwent either carotid artery stent placement (CAS) or carotid endarterectomy (CEA).

METHODS

The rates of 5-year survival were determined by use of Kaplan-Meier survival methods in a representative sample of fee-for-service Medicare beneficiaries ≥65 years of age who underwent CAS or CEA for asymptomatic carotid artery stenosis with postprocedural follow-up of 3.4 ± 1.7 years. Cox proportional hazards analysis was used to assess the relative risk of all-cause mortality for patients in the presence of selected comorbidities, including ischemic heart disease, chronic renal failure, and atrial fibrillation, after adjustment for potential confounders such as age, sex, race/ethnicity, and procedure type.

RESULTS

A total of 22,177 patients with asymptomatic carotid artery stenosis were treated with either CAS (n = 2144) or CEA (n = 20,033). The overall estimated 5-year survival rate (±SE) was 95.3 ± 0.00149; it was 95.5% and 93.8% in patients treated with CEA and CAS, respectively. After adjustment for potential confounders, relative risk of all-cause 5-year mortality was significantly higher among patients with atrial fibrillation (relative risk, 1.8; 95% confidence interval, 1.5-2.1) and those with chronic renal failure (relative risk, 2.1; 95% confidence interval, 1.7-2.6).

CONCLUSION

Risks and benefits must be carefully weighed before carotid revascularization in elderly patients with asymptomatic carotid artery stenosis who have concurrent atrial fibrillation or chronic renal failure.

The effect of chronic renal insufficiency by use of glomerular filtration rate versus serum creatinine level on late clinical outcome of carotid endarterectomy

BACKGROUND

Several studies have reported mixed results after carotid endarterectomy (CEA) in patients with chronic renal insufficiency (CRI), and we previously reported the perioperative outcome in patients with CRI by use of serum creatinine (Cr) level and glomerular filtration rate (GFR). However, only a few of these studies used GFR by the Modification of Diet in Renal Disease equation in their analysis of long-term outcome.

METHODS

During the study period, 1000 CEAs (926 patients) were analyzed; 940 of these CEAs had Cr levels and 925 had GFR data. Patients were classified into normal (GFR ≥60 mL/min/1.73 m(2) or Cr <1.5 mg/dL), moderate CRI (GFR ≥30-59 or Cr ≥1.5-2.9), and severe CRI (GFR <30 or Cr ≥3).

RESULTS

At a mean follow-up of 34.5 months and a median of 34 months (range, 1-53 months), combined stroke and death rates for Cr levels (867 patients) were 9%, 18%, and 44% for Cr <1.5, ≥1.5 to 2.9, and ≥3 (P = .0001) in contrast to 8%, 14%, and 26% for GFR (854 patients) of >60, ≥30 to 59, and <30, respectively (P = .0003). Combined stroke and death rates for asymptomatic patients were 8%, 17%, and 44% (P = .0001) for patients with Cr levels of <1.5, ≥1.5 to 2.9, and ≥3, respectively, vs 7%, 13%, and 24% for a GFR of ≥60, ≥30 to 59, and <30 (P = .0063). By Kaplan-Meier analysis, stroke-free survival rates at 1 year, 2 years, and 3 years were 97%, 94%, and 92% for Cr <1.5; 92%, 85%, and 81% for Cr ≥1.5 to 2.9; and 56%, 56%, and 56% for Cr ≥3 (P < .0001); vs 98%, 95%, and 93% for a GFR ≥60; 93%, 90%, and 86% for a GFR of ≥30 to 59; and 86%, 77%, and 73% for a GFR <30 (P < .0001). These rates for asymptomatic patients at 1 year, 2 years, and 3 years were 97%, 95%, and 93% for Cr <1.5; 94%, 87%, and 82% for Cr ≥1.5 to 2.9; and 56%, 56%, and 56% for Cr ≥3 (P < .0001); vs 98%, 95%, and 94% for a GFR ≥60; 95%, 91%, and 86% for a GFR of ≥30 to 59; and 84%, 80%, and 75% for a GFR <30 (P = .0026). A univariate regression analysis for asymptomatic patients showed that the hazard ratio (HR) of stroke and death was 6.5 (P = .0003) for a Cr ≥3 and 3.1 for a GFR <30 (P = .0089). A multivariate analysis showed that Cr ≥3 had an HR of stroke and death of 4.7 (P = .008), and GFR <30 had an HR of 2.2 (P = .097).

CONCLUSIONS

Patients with severe CRI had higher rates of combined stroke/death. Therefore, CEA for these patients (particularly in asymptomatic patients) must be considered with caution.

Impact of chronic renal insufficiency on the early and late clinical outcomes of carotid artery stenting using serum creatinine vs glomerular filtration rate

BACKGROUND

This study analyzed the impact of chronic renal insufficiency (CRI) on early and late clinical outcomes of carotid artery stenting (CAS) using serum creatinine and glomerular filtration rate (GFR).

STUDY DESIGN

There were 313 CAS patients classified into 3 groups: normal (serum creatinine <1.5 mg/dL or GFR ≥ 60 mL/min/1.73 m(2)); moderate CRI, and severe CRI (serum creatinine ≥ 3 or GFR < 30 mL/min/1.73 m(2)). Major adverse events ([MAE] stroke, death, and myocardial infarction) were compared for all groups.

RESULTS

Using serum creatinine, perioperative stroke rates for normal, moderate, and severe CRI were: 5%, 0%, and 25%, respectively, (p = 0.05) vs 4.6%, 3.7%, and 11.1%, respectively, (p = 0.44) using GFR. The perioperative MAE rates for symptomatic patients were 9.3% and 0% (p = 0.355) and 2% and 5.9% (p = 0.223) for asymptomatic patients for normal and moderate/severe CRI, respectively, using serum creatinine vs 8.1% and 7.8%, respectively, for symptomatic patients and 2.5% and 3%, respectively, for asymptomatic patients using GFR. At a mean follow-up of 21 months, late MAE rates in normal vs moderate/severe CRI patients were 8.2% and 14%, respectively, (p = 0.247) using serum creatinine vs 6.6% and 13.3%, respectively, (p = 0.05) using GFR. Late MAE rates for symptomatic patients in normal vs moderate/severe CRI were: 8.7% vs 27%, respectively, (p = 0.061) using serum creatinine and 5.7% vs 18.8%, respectively, (p = 0.026) using GFR. Late death rate was 0.55% in normal vs 7.6% (p = 0.002) for moderate/severe CRI. Freedom from MAE at 3 years in symptomatic patients was 81% in normal and 46% in moderate/severe CRI (p = 0.0198). A multivariate Cox regression analysis showed that a GFR of < 60 mL/min/1.73 m(2) had an odds ratio of 1.6 (p = 0.222) of having a MAE after CAS.

CONCLUSIONS

The GFR was more sensitive in detecting late MAE after CAS. Carotid artery stenting in moderate CRI patients can be done with a satisfactory perioperative outcome; however, late death was significant.

Outcomes of carotid revascularization in patients with chronic kidney disease

Chronic kidney disease (CKD) carries an increased risk for cardiovascular disease (CVD) including cerebrovascular accidents (CVAs). There are multiple etiologies for CVA, and among them extracranial carotid artery disease accounts for approximately 25% of ischemic strokes. It has been shown that carotid revascularization by carotid endarterectomy and carotid artery angioplasty and stenting can decrease the risk of CVA in appropriately selected population with carotid artery disease. Both these techniques of carotid revascularization have been shown to be safe and clinically effective in many large multicentered randomized clinical trials. However, most of these large trials have predominately excluded the patients with kidney failure. Most of the evidence for the management of carotid disease in CKD is based on small clinical trials and expert opinions. There is an urgent need to conduct large clinical trials in patients with CKD to enable better understanding and to improve techniques of various carotid revascularization therapies in CKD patients.

Patients Requiring Dialysis are not at Risk of Greater Complication after Carotid Endarterectomy

Stroke is a leading cause of disability and the third leading cause of death. Landmark studies have demonstrated that carotid endarterectomy (CEA) reduced the risk of stroke among selected patients with carotid stenosis. Renal insufficiency is a known risk factor for stroke and appears to be an independent risk factor for poor outcome after CEA. Studies have reported high morbidity and mortality after CEA in patients on dialysis. However, our experience has been that patients undergoing dialysis have no greater risk for a poor outcome. This study was a retrospective review of our CEA patients to ascertain our morbidity and mortality results in dialysis patients versus patients not on dialysis. An institutional retrospective chart review of CEAs from January 1999 to December 2007 was conducted. Patients on dialysis at the time of CEA were identified. Their charts were reviewed for complications 30 days after surgery. This was compared with our total experience with CEAs from January 1999 to December 2007. Of the 28 patients undergoing CEA while dialysis dependent, none had complications in the 30-day postoperative period. This compares favorably with the cohort of all CEAs by the same surgeons. In that group, 13 complications were identified (13 of 1,141). Patients undergoing dialysis are at no greater risk for complications when undergoing carotid endarterectomy than the general population.