Outcomes of carotid artery stenting and endarterectomy in the United States

Timing of Carotid Intervention in Symptomatic Carotid Artery Stenosis: A Systematic Review and Meta-Analysis

OBJECTIVE

This review aimed to analyse the timing of carotid endarterectomy (CEA) and carotid artery stenting (CAS) after the index event as well as 30 day outcomes at varying time periods within 14 days of symptom onset.

METHODS

A systematic review was performed according to the Preferred Reporting Items for Systematic reviews and Meta-analysis statement, comprising an online search of the Medline and Cochrane databases. Methodical quality assessment of the included studies was performed. Endpoints included procedural stroke and/or death stratified by delay from the index event and surgical technique (CEA/CAS).

RESULTS

Seventy-one studies with 232 952 symptomatic patients were included. Overall, 34 retrospective analyses of prospective databases, nine prospective, three RCT, three case control, and 22 retrospective studies were included. Compared with CEA, CAS was associated with higher 30 day stroke (OR 0.70; 95% CI 0.58 - 0.85) and mortality rates (OR 0.41; 95% CI 0.31 - 0.53) when performed ≤ 2 days of symptom onset. Patients undergoing CEA/CAS were analysed in different time frames (≤ 2 vs. 3 - 14 and ≤ 7 vs. 8 - 14 days). Expedited CEA (vs. 3 - 14 days) presented a sampled 30 day stroke rate of 1.4%; 95% CI 0.9 - 1.8 vs. 1.8%; 95% CI 1.8 - 2.0, with no statistically significant difference. Expedited CAS (vs. 3 - 14 days) was associated with no difference in stroke rate but statistically significantly higher mortality rate (OR 2.76; 95% CI 1.39 - 5.50).

CONCLUSION

At present, CEA is safer than transfemoral CAS within 2/7 days of symptom onset. Also, considering absolute rates, expedited CEA complies with the accepted thresholds in international guidelines. The ideal timing for performing CAS (when indicated against CEA) is not yet defined. Additional granular data and standard reporting of timing of intervention will facilitate future monitoring.

In-hospital outcomes alone underestimate rates of 30-day major adverse events after carotid artery stenting

OBJECTIVE

Outcome studies using databases collecting only hospital discharge data underestimate morbidity and mortality because of failure to capture postdischarge events. The proportion of postdischarge major adverse events is well characterized in patients undergoing carotid endarterectomy (CEA) but has yet to be characterized after carotid artery stenting (CAS).

METHODS

We retrospectively reviewed all patients undergoing CAS from 2011 to 2017 using the American College of Surgeons National Surgical Quality Improvement Program procedure targeted database to evaluate rates of 30-day major adverse events, stratified by in-hospital and postdischarge occurrences. The primary outcome was 30-day stroke/death. Multivariable analysis using purposeful selection was used to identify independent factors associated with in-hospital, postdischarge, and 30-day stroke/death events.

RESULTS

Of the 899 patients undergoing CAS, reporting of in-hospital outcomes alone would yield a stroke/death rate of 2.7%, substantially underestimating the 30-day stroke/death rate of 4.0%. In fact, 35% of stroke/deaths, 27% of strokes, 73% of deaths, 35% of cardiac events, and 35% of stroke/death/cardiac events occurred after discharge. More postdischarge stroke/death events occurred after treatment of symptomatic compared with asymptomatic patients (47% vs 27%; P < .001). During this same study period, the 30-day stroke/death rate after CEA was 2.6%, with similar proportions of postdischarge strokes (28% vs 27%; P = .51) compared with CAS but lower proportions of postdischarge deaths (55% vs 73%; P < .001). After CAS, patients experiencing postdischarge stroke/death events had a shorter postoperative length of stay compared with patients with in-hospital stroke/death (1 [1-2] vs 5 [3-10] days; P < .001). Chronic obstructive pulmonary disease was independently associated with postdischarge stroke/death (odds ratio [OR], 4.4; 95% confidence interval [CI], 1.2-16; P = .02) after CAS. Nonwhite ethnicity was independently associated with overall 30-day stroke/death (OR, 3.4; 95% CI, 1.4-7.9; P < .01), whereas statin use was associated with not having stroke/death within 30 days (OR, 0.5; 95% CI, 0.2-1.0; P = .049).

CONCLUSIONS

More than one-quarter of perioperative strokes occur following discharge after both CAS and CEA. A higher proportion of postdischarge deaths occur after CAS in symptomatic patients, which may reflect treatment of a population of higher risk patients. Further investigation is needed to elucidate the cause of postdischarge stroke to develop methods to reduce these complications.

The utility of adjunctive electroencephalography while performing transcarotid artery revascularization

Transcarotid artery revascularization (TCAR) has been used as an alternative to carotid endarterectomy and transfemoral carotid artery stenting. Although TCAR has been associated with a decrease in perioperative strokes compared with transfemoral carotid artery stenting, little is known about the safety of cerebral blood during flow reversal or the value of adjunctive electroencephalography (EEG) monitoring in performing TCAR. We describe two cases of EEG changes in patients undergoing TCAR. These cases highlight the use of adjunctive EEG and provide examples of test clamping to assess for compromised collateral cerebral blood flow in patients undergoing TCAR.

Sensitivity of Administrative Coding in Identifying Inpatient Acute Strokes Complicating Procedures or Other Diseases in UK Hospitals

Background

Administrative hospital diagnostic coding data are increasingly used in “big data” research and to assess complication rates after surgery or acute medical conditions. Acute stroke is a common complication of several procedures/conditions, such as carotid interventions, but data are lacking on the sensitivity of administrative coding in identifying acute stroke during inpatient stay.

Methods and Results

Using all acute strokes ascertained in a population‐based cohort (2002–2017) as the reference, we determined the sensitivity of hospital administrative diagnostic codes (International Classification of Diseases, Tenth Revision; ICD‐10) for identifying acute strokes that occurred during hospital admission for other reasons, stratified by coding strategies, study periods, and stroke severity (National Institutes of Health Stroke Score</≥5). Of 3011 acute strokes, 198 (6.6%) occurred during hospital admissions for procedures/other diseases, including 122 (61.6%) major strokes. Using stroke‐specific codes (ICD‐10=I60–I61 and I63–I64) in the primary diagnostic position, 66 of the 198 cases were correctly identified (sensitivity for any stroke, 33.3%; 95% CI, 27.1–40.2; minor stroke, 30.3%; 95% CI, 21.0–41.5; major stroke, 35.2%; 95% CI, 27.2–44.2), with no improvement of sensitivity over time (P_trend=0.54). Sensitivity was lower during admissions for surgery/procedures than for other acute medical admissions (n/% 17/23.3% versus 49/39.2%; P=0.02). Sensitivity improved to 60.6% (53.6–67.2) for all and 61.6% (50.0–72.1) for surgery/procedures if other diagnostic positions were used, and to 65.2% (58.2–71.5) and 68.5% (56.9–78.1) respectively if combined with use of all possible nonspecific stroke‐related codes (ie, adding ICD‐10=I62 and I65–I68).

Conclusions

Low sensitivity of administrative coding in identifying acute strokes that occurred during admission does not support its use alone for audit of complication rates of procedures or hospitalization for other reasons.

Racial and Socioeconomic Disparities After Carotid Procedures

Background:

Race has been associated with inferior outcomes after multiple procedures, but the association of socioeconomic status with procedures for cerebrovascular disease is not well established.

Materials and Methods:

Elective carotid artery stenting (CAS) and carotid endarterectomy (CEA) procedures were identified in the National Inpatient Sample, 2012 to 2014. Median household income was estimated from patient ZIP codes. Chi-square and multivariable logistic regression analysis evaluated outcomes, accounting for age, race, gender, comorbidities, procedure, income, insurance, and hospital characteristics.

Results:

We identified 234 825 carotid procedures (205 835 CEA and 28 990 CAS). Blacks and Hispanics were more likely to be among the lowest quartile income patients (LQIPs) compared to whites (53.5% and 38.7% vs 27.0%, respectively; P < .0002). Compared to highest income quartile patients, LQIP had lower rates of private insurance (16.3% vs 22.0%) and higher Medicaid use (4.7% vs 2.0%; all P < .0002). Lowest quartile income patients were more likely to receive CAS (odds ratio [OR] = 1.32, 95% confidence interval [CI]: 1.27-1.37), as were blacks and Hispanics (OR = 1.09, 95% CI: 1.02-1.26; OR = 1.31, 95% CI: 1.24-1.40, respectively). In multivariable regression, postoperative stroke was associated with LQIP, black race, and Hispanic ethnicity (OR = 1.16, 95% CI: 1.06-1.28; OR = 1.52, 95% CI: 1.33-1.73; OR = 1.43, 95% CI: 1.24-1.64, respectively). Subgroup analysis demonstrated that whites also had higher odds of stroke in the lower income quartile (OR = 1.2, 95% CI: 1.1-1.4). Mortality was associated with LQIP (OR = 1.6, 95% CI: 1.2-2.1), black race (OR = 1.8, 95% CI: 1.4-2.5), and CAS (OR = 1.3, 95% CI: 1.1-1.6). Length of stay in the lowest income quartile was longer than in patients with the highest income ( P < .0001).

Conclusions:

Race was associated with increased hospital mortality, postoperative stroke, and overall complications after carotid procedures. Lower income was significantly associated with increased stroke and mortality irrespective of race. Disparate utilization and outcomes for carotid procedures are multifactorial. Efforts to reduce disparities will need to focus on race and other socioeconomic factors.

Is carotid sonography a useful tool for predicting functional capabilities in ischemic stroke patients following carotid artery stenting?

Carotid stenosis is a major cause of stroke and timely intervention with stenting manipulation can significantly reduce the risk of secondary stroke. The impact of stenting procedures on patient functional capabilities has not yet been explored. The primary aim of this study was to examine associations between periprocedural carotid sonography parameters and post-treatment functional capabilities in stroke patients.Sixty-seven patients who received carotid stenting at 1 angiography laboratory were included. Prestenting and poststenting carotid duplex data were recorded and resistance index (RI) differences at various carotid system locations were compared. The modified Rankin Scale (mRS) was used to assess functional capability. All of the studied parameters were analyzed by SPSS (version 16.0, SPSS Inc, Chicago, IL).Following stenting, mRS scores improved (n = 44) or remained stationary (n = 23). Net contralateral internal carotid artery (ICA) RI for patients with improved mRS was lower compared to that for patients with stationary mRS (median = 0.040 vs 0.11; P = 0.003). The contralateral common carotid artery RI before and after stenting differed significantly (P < 0.050) in both. The ipsilateral ICA RI differed (P < 0.050) only in patients with improved mRS. The difference in mean transit time, Barthel index, net ipsilateral ICA RI, net contralateral external carotid artery RI, postipsilateral common carotid artery RI, and postipsilateral ICA RI differed significantly between different baseline stroke severity groups (P < 0.050).Carotid artery stenting improved physical function in a proportion of ischemic stroke patients with carotid stenosis. Carotid ultrasound is a useful assessment tool to predict likely functional outcomes following carotid artery stenting.

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.

Carotid stenting versus endarterectomy for the treatment of carotid artery stenosis: Contemporary results from a large single center study

OBJECTIVE

To compare the complication rates associated with carotid endarterectomy (CEA) versus carotid artery stenting (CAS).

BACKGROUND

Carotid stenosis is a well-known cause of stroke and increased mortality. The safety of carotid revascularization may be related to symptom status, medical comorbidities, use of embolic protection devices, as well as operator experience and these factors may vary across patient populations within a single operating center.

METHODS

We retrospectively analyzed patients with carotid artery stenosis admitted to our hospital for carotid revascularization between January 1, 2007 and December 1, 2013. The primary end point was a composite endpoint of periprocedural death, stroke, and myocardial infarction (MI).

RESULTS

Of the 718 patients admitted for carotid revascularization 525 (73.1%) underwent CEA and 193 (26.9%) underwent CAS. Both groups demonstrated similar rates of the composite endpoint, MI, and death; the stenting group demonstrated a higher rate of stroke (4.2% vs. 1.3%; P = 0.020). Adjusting for baseline medical comorbidities and symptom status mitigated this difference (P = 0.091 and 0.113, respectively). When stratified by department performing CAS, there was a significant difference in the occurrence of stroke (P = 0.033), which likewise disappeared in the multivariate regression analysis.

CONCLUSION

The risk of the composite endpoint did not differ significantly between those undergoing CAS versus CEA. The stenting group demonstrated a higher rate of periprocedural stroke, which was also apparent when patients were stratified by stenting department. These differences were likely driven by variation in baseline medical comorbidities and symptom status. © 2016 Wiley Periodicals, Inc.

Impact of baseline characteristics on outcomes of carotid artery stenting in acute ischemic stroke patients

Carotid artery stenting is an effective treatment for ischemic stroke patients with moderate-to-severe carotid artery stenosis. However, the midterm outcome for patients undergoing this procedure varies considerably with baseline characteristics. To determine the impact of baseline characteristics on outcomes following carotid artery stenting, data from 107 eligible patients with a first episode of ischemic stroke were collected by retrospective chart review. A modified Rankin Scale (mRS) was used to divide patients into two baseline groups, mRS ≤2 and mRS >2. A three-step decision-tree statistical analysis was conducted. After weighting the decision-tree parameters, the following impact hierarchy was obtained: admission low-density lipoprotein, gouty arthritis, chronic kidney disease, ipsilateral common carotid artery resistance index, contralateral ophthalmic artery resistance index, sex, and dyslipidemia. The finite-state machine model demonstrated that, in patients with baseline mRS ≤2, 46% had an improved mRS score at follow-up, whereas 54% had a stable mRS score. In patients with baseline mRS >2, a stable mRS score was observed in 75%, improved score in 23%, and a poorer score in 2%. Admission low-density lipoprotein was the strongest predictive factor influencing poststenting outcome. In addition, our study provides further evidence that carotid artery stenting can be of benefit in first-time ischemic stroke patients with baseline mRS scores >2.

Outcomes of 1000 Carotid Wallstent Implantations

Purpose: To evaluate the outcomes of carotid artery stenting (CAS) with Wallstents in a single-center experience. Methods: From January 2003 to December 2013, 1000 carotid artery lesions were treated with Carotid Wallstents under cerebral protection in 877 patients (mean age 71.7±8 years; 621 men). Indications for treatment were de novo lesions (>70% asymptomatic and >60% symptomatic); stenoses following carotid endarterectomy, radiation, or neck surgery; contralateral laryngeal nerve palsy; and high surgical risk. All the patients underwent duplex ultrasound and clinical evaluation during follow-up; radiography was performed when fracture or stent migration was suggested by ultrasound. Results: Procedure success was achieved in 99.3% of patients. Major and minor 30-day adverse events occurred in 2.1% of patients, including stroke (1.8%: 1.3% minor, 0.5% major), myocardial infarction (0.1%), and death (0.2%). Plaque morphology, nature of stenosis, and symptomatic status were significantly associated with the risk of postoperative neurologic events. Restenosis occurred in 3.2% at a mean 45.5-month follow-up and was significantly associated with diabetes, smoking, symptomatic stenosis, de novo stenosis, and calcification (plaque III/IV). No fracture or migration was registered during follow-up. Conclusion: CAS is a valid method for treating carotid artery disease, with very low rates of major adverse events and neurologic complications. The Carotid Wallstent seems to have excellent results, even with complex plaque morphology, and a low incidence of restenosis at follow-up.

Adverse Events in Carotid Endarterectomy From a Medicolegal Perspective

Objectives:

Characterize factors raised in carotid endarterectomy litigation.

Methods:

Outcomes, alleged causes of malpractice, and other factors were evaluated.

Results:

Of the 37 verdicts and settlements, defendants were not liable in 25 (67.5%) cases. Frequently reported complications included stroke (51.3%) and hypoglossal nerve injury (27.0%), with other complications including airway compromise, vocal cord injury, and death. No cases reported myocardial infarction. Cerebral monitoring was mentioned in 2 cases, while inadequate informed consent, delayed diagnosis, and requirement of additional surgery were alleged in numerous instances. Settlements and jury awards averaged US$895 833 and US$1.53 million, respectively.

Conclusions:

Stroke and hypoglossal nerve injury are the most frequently litigated complications, and mean damages awarded were considerable. Knowledge of issues raised in our analysis may be included in a comprehensive consent process, potentially minimizing liability and improving patient safety.

Institutional Differences in Carotid Artery Duplex Diagnostic Criteria Result in Significant Variability in Classification of Carotid Artery Stenoses and Likely Lead to Disparities in Care

Background—

The indications for carotid revascularization are based almost exclusively on the results of carotid duplex ultrasonography. Noninvasive vascular laboratories show large variation in the diagnostic criteria used to classify degree of carotid artery stenosis. We hypothesize that variability of these diagnostic criteria causes significant variation in stenosis classification directly affecting the number of revascularizations and associated costs.

Methods and Results—

The diagnostic criteria to interpret carotid duplex ultrasounds were obtained from 10 New England institutions. All carotid duplex scans performed at our institution were reviewed from 2008 to 2012. Using the diagnostic criteria from each institution, the degree of stenosis that would have been reported was classified as 70% to 99% asymptomatic, 80% to 99% asymptomatic, and 50% to 99% symptomatic. We then calculated the theoretical number of carotid revascularization procedures that this cohort would be offered using each institution’s diagnostic criteria and the costs of these procedures based on reimbursement rates. Among 10 614 patients who underwent 15 534 carotid duplex scans, 31 025 arteries were reviewed. Application of the 10 institutions’ criteria to the patients from our institution yielded marked variation in the number classified as 70% to 99% asymptomatic (range, 186–2201), 80% to 99% asymptomatic (range, 78–426), and 50% to 99% symptomatic (range, 157–781). If revascularizations were based on these results, costs would range from $2.2 to $26 million, $0.9 to $5.0 million, and $1.9 to $9.2 million, respectively.

Conclusions—

Differences in diagnostic criteria to interpret carotid ultrasound result in significant variation in classification of carotid artery stenosis, likely leading to differences in the number and subsequent costs of revascularizations. This theoretical model highlights the need for standardization of carotid duplex criteria.

Acute ischaemic stroke outcomes following mechanical thrombectomy in the elderly versus their younger counterpart: a retrospective cohort study

OBJECTIVES

Many physicians debate the efficacy of mechanical thrombectomy for ischaemic stroke, but most agree that to establish potential benefit, patient selection must be examined further. People >80 years are a growing population of patients with ischaemic stroke but are largely excluded from clinical trials. The benefit of thrombectomy for them may be greatly reduced due to diminishing neuroplasticity and a larger number of medical comorbidities. To address this knowledge gap, we examined clinical and economic outcomes after mechanical thrombectomy in the ischaemic stroke population from the Nationwide Inpatient Sample. Our null hypotheses were that elderly patients (>80 years) would have a similar rate of inpatient mortality in comparison to their younger counterparts and incur a similar economic expense.

DESIGN

Retrospective cohort study.

SETTING

A 20% stratified sample of US community hospitals within the Nationwide Inpatient Sample.

PARTICIPANTS

All patients from 2008 to 2010 with a primary diagnosis of ischaemic stroke that received mechanical thrombectomy were included.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was inpatient mortality. Secondary outcomes included hospital charges and length of stay.

RESULTS

Less than 1% of all ischaemic stroke cases (9300) were treated with mechanical thrombectomy. Of these, 18% involved patients over 80 years of age. The odds of inpatient mortality in elderly patients treated with mechanical thrombectomy were approximately twice that of their younger counterparts (OR1.993, p < 0.001). The elderly experienced no significant difference in hospital charges (p=0.105) and length of stay (p=0.498).

CONCLUSIONS

The odds of inpatient mortality after mechanical thrombectomy in patients over 80 years of age were twice that of their younger counterparts. This is consistent with the overall worse prognosis seen in the natural history of this age group. Studies to better identify patients that would benefit from endovascular mechanical thrombectomy may improve outcomes and reduce the gap currently observed in age stratifications.

The impact of the present on admission indicator on the accuracy of administrative data for carotid endarterectomy and stenting

BACKGROUND

Administrative data are often hampered by coding errors, absent data, and the difficulty of distinguishing pre-existing conditions from perioperative complications. We evaluated whether the introduction of the present on admission (POA) indicator improved outcome analysis of carotid endarterectomy (CEA) and carotid angioplasty and stenting (CAS) using administrative data.

METHODS

State inpatient databases from California (2005-2008), New York (2008), and New Jersey (2008) were used to identify patients undergoing CAS and CEA. We first analyzed morbidity data without the POA indicator, using International Classification of Diseases, Ninth Revision complication codes (eg, 997.02, iatrogenic cerebrovascular infarction or hemorrhage, postoperative stroke) and diagnosis codes (eg, 433.11, occlusion and stenosis of the carotid artery with cerebral infarction). Then, we applied the POA indicator to both diagnosis and complication codes and calculated the proportion of events that were labeled POA. Symptom status and perioperative stroke rate were compared using these coding approaches.

RESULTS

We identified 21,639 patients who underwent CEA and 3688 patients who underwent CAS. Without the POA indicator, the complication code for stroke indicated a postoperative stroke rate of 1.4% for CEA and 2.4% for CAS. After applying the POA indicator, 54% (CEA) and 62% (CAS) of these strokes were labeled POA. These POA strokes were either preoperative or intraoperative events. Proportion of symptomatic patients ranged from 7% to 16% for CEA and from 5% to 22% for CAS. Perioperative stroke rate was the lowest in the POA method (1.1% CEA, 1.8% CAS) compared with two other methods without POA information (1.4% and 9.5% CEA and 2.4% and 16.4% CAS). Kappa indicated a poor (0.2) to fair (0.7) agreement between these approaches.

CONCLUSIONS

Administrative data has known limitations for assignment of symptom status and nonfatal perioperative outcomes. Given the uncertain timing of POA events as preoperative vs intraoperative and its apparent underestimation of the perioperative stroke rate, the use of administrative data even with the POA indicator for symptom status and non-fatal outcomes after CEA and CAS is hazardous.

Accuracy of administrative data versus clinical data to evaluate carotid endarterectomy and carotid stenting

OBJECTIVE

Administrative data have been used to compare carotid endarterectomy (CEA) and carotid artery stenting (CAS). However, there are limitations in defining symptom status, Centers for Medicare and Medicaid Services high-risk status, as well as complications. Therefore, we did a direct comparison between administrative data and physician chart review as well as between data collected for the National Surgical Quality Improvement Program (NSQIP) and physician chart review for CEA and CAS.

METHODS

We performed an outcomes analysis on all CEA and CAS procedures from 2005 to 2011. We obtained International Classification of Diseases, Ninth Revision diagnosis codes from hospital discharge records regarding symptom status, high-risk status, and perioperative stroke. We also obtained data on all CEA patients submitted to NSQIP over the same time period. One of the study authors (R.B.) then performed a chart review of the same patients to determine symptom status, high-risk status, and perioperative strokes and the results were compared.

RESULTS

We identified 1342 patients who underwent CEA or CAS between 2005 and 2011 and 392 patients who underwent CEA that were submitted to NSQIP. Administrative data identified fewer symptomatic patients (17.0% vs 34.0%), physiologic high-risk patients (9.3% vs 23.0%), and anatomic high-risk patients (0% vs 15.2%). Although administrative data identified a similar proportion of perioperative strokes (1.9% vs 2.0%), this was due to the fact that these data identified eight false positive and nine false negative perioperative strokes. NSQIP data identified more symptomatic patients compared with chart review (44.1% vs 30.3%), fewer physiologic high-risk patients (13.0% vs 18.6%), fewer anatomic high-risk patients (0% vs 6.6%), and a similar proportion of perioperative strokes (1.5% vs 1.8%, only one false negative stroke and no false positives).

CONCLUSIONS

Administrative data are unreliable for determining symptom status, high-risk status, and perioperative stroke and should not be used to analyze CEA and CAS. NSQIP data do not adequately identify high-risk patients, but do accurately identify perioperative strokes and to a lesser degree, symptom status.

In-hospital versus postdischarge adverse events following carotid endarterectomy

OBJECTIVE

Most studies based on state and nationwide registries evaluating perioperative outcome after carotid endarterectomy (CEA) rely on hospital discharge data only. Therefore, the true 30-day complication risk after carotid revascularization may be underestimated.

METHODS

We used the National Surgical Quality Improvement Program database 2005-2010 to assess the in-hospital and postdischarge rate of any stroke, death, cardiac event (new Q-wave myocardial infarction or cardiac arrest), and combined stroke/death and combined adverse outcome (S/D/CE) at 30 days following CEA. Multivariable analyses were used to identify predictors for in-hospital and postdischarge events separately, and in particular, those that predict postdischarge events distinctly.

RESULTS

A total of 35,916 patients who underwent CEA during 2005-2010 were identified in the National Surgical Quality Improvement Program database; 59% were male, median age was 72 years, and 44% had a previous neurologic event. Thirty-day stroke rate was 1.6% (n = 591), death rate was 0.8% (n = 272), cardiac event rate was 1.0% (n = 350), stroke or death rate was 2.2% (n = 794), and combined S/D/CE rate was 2.9% (n = 1043); 33% of strokes, 53% of deaths, 32% of cardiac events, 40% of combined stroke/death, and 38% of combined S/D/CE took place after hospital discharge. Patients with a prior stroke or transient ischemic attack had similar proportions of postdischarge events compared with patients without prior symptoms. Independent predictors for postdischarge events, but not for in-hospital events were female sex (stroke [odds ratio (OR), 1.6; 95% confidence interval (CI), 1.2-2.1] and stroke/death [OR, 1.4; 95% CI, 1.1-1.7]), renal failure (stroke [OR, 3.0; 95% CI, 1.4-6.2]) and chronic obstructive pulmonary disease (death [OR, 2.5; 95% CI, 1.6-3.7], stroke/death [OR, 1.8; 95% CI, 1.4-2.4], and S/D/CE [OR 1.8, 95% CI 1.4-2.3]).

CONCLUSIONS

With 38% of perioperative adverse events after CEA happening posthospitalization, regardless of symptoms status, we need to be alert to the ongoing risks after discharge particularly in women, patients with renal failure, or chronic obstructive pulmonary disease. This emphasizes the need for reporting and comparing 30-day adverse event rates when evaluating outcomes for CEA, or comparing carotid stenting to CEA.

Carotid Artery Stenting - Strategies to Improve Procedural Performance and Reduce the Learning Curve

Carotid artery stenting (CAS) remains an appealing intervention to reduce the stroke risk because of its minimal invasive nature. Nevertheless, landmark randomised controlled trials have not been able to resolve the controversies surrounding this complex procedure as the peri-operative stroke risk in a non-selected patient population still seems to be higher after CAS in comparison to carotid endarterectomy. What is more, these trials have highlighted that patient outcome after CAS is influenced by patient- and operator-dependant factors. The CAS procedure exhibits a definitive learning curve resulting in higher complication rates if the procedure is performed by inexperienced interventionists or in low-volume centres. This article will outline strategies to improve the performance of physicians carrying out the CAS procedure by means of proficiency-based training, credentialing, virtual reality rehearsal and optimal patient selection.

Reasons why data from the Nationwide Inpatient Sample can be misleading for carotid endarterectomy and carotid stenting

The Nationwide Inpatient Sample (NIS) is often used for population-based research comparing the safety of carotid artery stenting (CAS) to that of carotid endarterectomy (CEA) in the United States. At least two findings from the NIS dataset seem questionable, however. First, several NIS studies indicate that >90% of CEAs and CAS procedures are currently being performed for asymptomatic carotid stenosis, which considerably exceeds the prevalence of asymptomatic patients reported elsewhere. Second, these studies also suggest that periprocedural stroke rates for CEA and CAS are collectively lower at hundreds of community hospitals contributing data to the NIS than they were in the Carotid Revascularization Endarterectomy Versus Stenting Trial (CREST), even though the participating surgeons and interventionalists in CREST were vetted on the basis of their previous experience and results. In addition, some unexpectedly low stroke to death ratios are present in NIS studies, implying that not all iatrogenic strokes have been entered into the NIS dataset. These issues might be related to inadequate documentation of preprocedural symptoms and periprocedural strokes in the medical records, leading to subsequent coding errors in the hospital discharge abstracts from which NIS data are extracted. The clinical limitations of the NIS and other administrative datasets have been pointed out in the past, but they appear to be particularly relevant to carotid interventions and must be recognized.

The Nationwide Inpatient Sample may contain inaccurate data for carotid endarterectomy and carotid stenting

The Nationwide Inpatient Sample (NIS) contains information from discharge abstracts submitted by hundreds of community hospitals across the United States, and it frequently has been used as a resource for population-based research comparing the safety of carotid artery stenting (CAS) to that of carotid endarterectomy (CEA). However, at least two findings from the NIS dataset seem open to question. First, several NIS studies have indicated that more than 90% of CEAs and CAS procedures now are being done in asymptomatic patients, a figure that substantially exceeds the prevalence of asymptomatic patients that has been reported elsewhere. Second, these studies also have suggested that the periprocedural stroke rate for CEA and CAS is lower at community hospitals contributing to the NIS than it was in the Carotid Revascularization Endarterectomy vs Stenting Trial (CREST), even though the surgeons and interventionalists participating in CREST were stringently selected according to their previous experience and results. Neither of these two findings seems to pass the test of face validity. Furthermore, some unexpectedly low stroke-to-death (STD) ratios are present in the NIS data, especially for CAS. These issues may be related to poor documentation of preprocedural symptoms and periprocedural strokes in the medical records and to subsequent coding errors in the hospital discharge abstracts on which the NIS is based.

Stroke and death after carotid endarterectomy and carotid artery stenting with and without high risk criteria

OBJECTIVE

Centers for Medicare and Medicaid Services (CMS) reimbursement criteria for carotid artery stenting (CAS) require that patients be high surgical risk or enrolled in a clinical trial. This may bias comparisons of CAS and carotid endarterectomy (CEA). We evaluate mortality and stroke following CAS and CEA stratified by medical high risk criteria.

METHODS

The Nationwide Inpatient Sample (2004-2007) was queried by ICD-9 code for CAS and CEA with diagnosis of carotid artery stenosis. Medical high risk criteria were identified for each patient including patients undergoing a coronary artery bypass and/or valve repair (CABG/V) during the same admission. Symptom status was defined by history of stroke, transient ischemic attack (TIA), and/or amarosis fugax. The primary outcome was postoperative death, stroke (complication code 997.02), and combined stroke or death, stratified by high risk vs non-high risk status and symptom status.

RESULTS

Patient totals of 56,564 (10.5%) CAS and 482,394 (89.5%) CEA were identified. Half of the patients in each group were high risk. CABG/V was performed less commonly with CAS than CEA (2.8% vs 4.0%, P < .001). Patients undergoing CAS were more likely symptomatic than those undergoing CEA (13.1% vs 9.4%, P < .001). Mortality was higher after CAS than CEA for both high risk and non-high risk patients. Stroke was also higher after CAS for both high risk and non-high risk patients. Combined stroke or death was higher after CAS again for both high risk (asymptomatic 1.5% vs 1.2%, P < .05, symptomatic 14.4% vs 6.9%, P < .001) and non-high risk (asymptomatic 1.8% vs 0.6%, P < .001, symptomatic 11.8% vs 4.9%, P < .001). Combined stroke or death for patients undergoing CABG/V during the same admission was similar for CAS and CEA (4.8% vs 3.2%, P = .19). Multivariate predictors of combined stroke or death adjusted for age and gender included CAS vs CEA (odds ratio [OR] 2.4, P < .001), symptom status (OR 6.8, P < .001), high risk (OR 1.6, P < .001), and earlier year of procedure (OR 1.1, P < .01).

CONCLUSIONS

In the United States from 2004 to 2007, CAS has a higher risk of stroke and death than CEA after adjustment for medical high risk criteria. Further analysis with prospective assessment of risk factors is needed to guide appropriate patient selection for CEA and CAS in the general population.

Postoperative sepsis in the United States

OBJECTIVES

To evaluate the incidence of postoperative sepsis after elective procedures, to define surgical procedures with the greatest risk for developing sepsis, and to evaluate patient and hospital confounders.

BACKGROUND DATA

The development of sepsis after elective surgical procedures imposes a significant clinical and resource utilization burden in the United States. We evaluated the development of sepsis after elective procedures in a nationally representative patient cohort and assessed the effect of sociodemographic and hospital characteristics on the development of postoperative sepsis.

METHODS

The Nationwide inpatient sample was queried between 2002 and 2006 and patients developing sepsis after elective procedures were identified using the patient safety indicator "Postoperative Sepsis" (PSI-13). Case-mix adjusted rates were calculated by using a multivariate logistic regression model for sepsis risk and an indirect standardization method.

RESULTS

A total of 6,512,921 weighted elective surgical cases met the inclusion criteria and 78,669 cases (1.21%) developed postoperative sepsis. Case-mix adjustment for age, race, gender, hospital bed size, hospital location, hospital teaching status, and patient income demonstrated esophageal, pancreatic, and gastric procedures represented the greatest risk for the development of postoperative sepsis. Thoracic, adrenal, and hepatic operations accounted for the greatest mortality rates if sepsis developed. Increasing age, Blacks, Hispanics, and men were more likely to develop sepsis. Decreased median household income, larger hospital bed size, urban hospital location, and nonteaching status were associated with greater rates of postoperative sepsis.

CONCLUSIONS

The development of postoperative sepsis is multifactorial and procedures, most likely to develop sepsis, did not demonstrate the greatest mortality after sepsis developed. Factors associated with the development of sepsis included race, age, hospital size, hospital location, and patient income. Further evaluation of high-risk procedures, populations, and environments may assist in reducing this costly complication.

Carotid Artery Stenting in the Nation: The Influence of Hospital and Physician Volume on Outcomes

Objectives: To assess national outcomes of carotid artery stenting (CAS) with respect to hospital and practitioner volume.

Methods: The 2005 to 2006 Nationwide Inpatient Sample (NIS) was used to assess CAS with respect to hospital volume, physician volume, and associated complications. Results: Eighteen thousand five hundred ninety-nine CAS interventions were identified. The top 25% was used to define high-volume hospitals (>60 CAS/2 years) and practitioners (>30 CAS/2 years). The stroke rate after CAS was significantly different between low- and high-volume hospitals (2.35% vs 1.78%, respectively; P = .0206). The stroke rate after CAS was also significantly different between low- and high-volume practitioners (2.19% vs 1.51%, P = .0243). Hospital resource use varied significantly between low- and high-volume hospitals (length of stay [LOS]: 1.64 ± 2.10 vs 1.45 ± 11.21, P = .0006; total charges: $32 261 ± 20 562 vs $30 131 ± 19 592, P = .0047) and practitioners (LOS: 1.70 ± 2.14 vs 1.36 ± 1.36; P < .0001; total charges: $33 762 ± 21 081 vs $23 957 ± 19 713; P < .0001). Conclusions: This analysis demonstrates that hospital and physician volume are associated with outcomes and utilization after CAS. High-volume hospitals and practitioners were associated with lower procedure stroke rates and decreased hospital resource utilization.