A comparison of outcomes associated with carotid artery stent placement performed within and outside clinical trials in the United States

Intra-arterial thrombolysis as adjunct to mechanical thrombectomy in acute ischemic stroke patients in the United States: A case control analysis

BACKGROUND

Although observational studies have reported favorable clinical outcomes associated with intra-arterial thrombolysis as adjunct to mechanical thrombectomy, the cost and length of hospitalization associated with this intervention has not been studied.

METHODS

We analyzed the nationally representative data of the United States data from Nationwide Inpatient Sample (NIS) to compare hospitalization cost and duration in addition to other outcomes in patients receiving (n = 1990) with those not receiving intra-arterial thrombolysis (n = 1990) in acute ischemic stroke patients undergoing mechanical thrombectomy using a case control design matched for age, gender, and presence of aphasia, hemiplegia, neglect, coma/stupor, hemianopsia and dysphagia.

RESULTS

There was no difference in the median hospitalization cost in patients treated with intra-arterial thrombolysis compared with those not treated with intra-arterial thrombolysis: $36,992 [28,361 to 54,336] versus $35,440 [24,383 to 50,438], (regression coefficient 2,485 [-1,947 to 6,917], p = 0.27). There was no difference in the median length of hospitalization in patients treated with intra-arterial thrombolysis compared with those not treated with intra-arterial thrombolysis: 6 days [3 to 10] versus 6 days [4 to 10], (regression coefficient -0.34 [-1.47 to 0.80], p = 0.56). There was no difference in odds of home-discharge (OR 1.02 95%CI 0.72-1.43, p = 0.93) or post-procedural intracranial hemorrhage (OR 1.16 95%CI 0.83-1.64, p = 0.39) between the two groups.

CONCLUSIONS

We did not observe an increase in the cost or length of hospitalization associated with the use of intra-arterial thrombolysis as adjunct to mechanical thrombectomy in acute ischemic stroke patients. If the ongoing randomized clinical trials demonstrate therapeutic efficacy in reducing death or disability, this intervention has a high likelihood of being beneficial overall.

Extra-Cranial Carotid Artery Stenosis: An Objective Analysis of the Available Evidence

Background and Purpose

Carotid stenosis is arterial disease narrowing of the origin of the internal carotid artery (main brain artery). Knowing how to best manage this is imperative because it is common in older people and an important cause of stroke. Inappropriately high expectations have grown regarding the value of carotid artery procedures, such as surgery (endarterectomy) and stenting, for lowering the stroke risk associated with carotid stenosis. Meanwhile, the improving and predominant value of medical intervention (lifestyle coaching and medication) continues to be underappreciated.

Methods and Results

This article aims to be an objective presentation and discussion of the scientific literature critical for decision making when the primary goal is to optimize patient outcome. This compilation follows from many years of author scrutiny to separate fact from fiction. Common sense conclusions are drawn from factual statements backed by original citations. Detailed research methodology is given in cited papers. This article has been written in plain language given the importance of the general public understanding this topic. Issues covered include key terminology and the economic impact of carotid stenosis. There is a summary of the evidence-base regarding the efficacy and safety of procedural and medical (non-invasive) interventions for both asymptomatic and symptomatic patients. Conclusions are drawn with respect to current best management and research priorities. Several "furphies" (misconceptions) are exposed that are commonly used to make carotid stenting and endarterectomy outcomes appear similar. Ongoing randomized trials are mentioned and why they are unlikely to identify a routine practice indication for carotid artery procedures. There is a discussion of relevant worldwide guidelines regarding carotid artery procedures, including how they should be improved. There is an outline of systematic changes that are resulting in better application of the evidence-base.

Conclusion

The cornerstone of stroke prevention is medical intervention given it is non-invasive and protects against all arterial disease complications in all at risk. The "big" question is, does a carotid artery procedure add patient benefit in the modern era and, if so, for whom?

Accurate classification of carotid endarterectomy indication using physician claims and hospital discharge data

BACKGROUND AND PURPOSE

Studies of carotid endarterectomy (CEA) require stratification by symptomatic vs asymptomatic status because of marked differences in benefits and harms. In administrative datasets, this classification has been done using hospital discharge diagnosis codes of uncertain accuracy. This study aims to develop and evaluate algorithms for classifying symptomatic status using hospital discharge and physician claims data.

METHODS

A single center's administrative database was used to assemble a retrospective cohort of participants with CEA. Symptomatic status was ascertained by chart review prior to linkage with physician claims and hospital discharge data. Accuracy of rule-based classification by discharge diagnosis codes was measured by sensitivity and specificity. Elastic net logistic regression and random forest models combining physician claims and discharge data were generated from the training set and assessed in a test set of final year participants. Models were compared to rule-based classification using sensitivity at fixed specificity.

RESULTS

We identified 971 participants undergoing CEA at the Vancouver General Hospital (Vancouver, Canada) between January 1, 2008 and December 31, 2016. Of these, 729 met inclusion/exclusion criteria (n = 615 training, n = 114 test). Classification of symptomatic status using hospital discharge diagnosis codes was 32.8% (95% CI 29-37%) sensitive and 98.6% specific (96-100%). At matched 98.6% specificity, models that incorporated physician claims data were significantly more sensitive: elastic net 69.4% (59-82%) and random forest 78.8% (69-88%).

CONCLUSION

Discharge diagnoses were specific but insensitive for the classification of CEA symptomatic status. Elastic net and random forest machine learning algorithms that included physician claims data were sensitive and specific, and are likely an improvement over current state of classification by discharge diagnosis alone.

Mechanical Thrombectomy in Acute Ischemic Stroke Patients Performed Within and Outside Clinical Trials in the United States

BACKGROUND

A better understanding of differences in outcomes of mechanical thrombectomy performed within and outside clinical trials will assist in optimal implementation of the procedure for acute ischemic stroke patients in general practice.

OBJECTIVE

To identify differences in demographic and clinical characteristics and outcomes related to mechanical thrombectomy in patients treated within clinical trials and those treated outside clinical trials in a large national cohort.

METHODS

We compared the patient characteristics and associated in-hospital outcomes of mechanical thrombectomy in acute ischemic stroke patients performed within and outside clinical trials using the Nationwide Inpatient Sample from 2013 to 2015. We analyzed in-hospital mortality (primary outcome) and moderate to severe disability (secondary outcome) based on discharge disposition after adjusting for potential confounders.

RESULTS

Of 23 375 patients who underwent mechanical thrombectomy, 430 (1.8%) underwent the procedure as part of a clinical trial. After adjusting for age, gender, and the teaching status of the hospital, patients treated within a clinical trial had lower rates of in-hospital mortality (odds ratio [OR] 0.14; 95% CI .03 to .71; P < .001). Among patients discharged alive, the rate of moderate to severe disability (OR .43; 95% CI .26 to .71; P < .001) was lower among those patients treated within a clinical trial. There was no difference in odds of post-thrombectomy intracerebral or subarachnoid hemorrhage between the two groups.

CONCLUSION

Mechanical thrombectomy performed as part of clinical trials was associated with lower rates of in-hospital mortality and lower rates of moderate to severe disability compared with those performed outside clinical trials.

Alcohol withdrawal is associated with poorer outcome in acute ischemic stroke

OBJECTIVE

To determine the association between alcohol abuse (AA) and alcohol withdrawal (AW) with acute ischemic stroke (AIS) outcomes.

METHODS

All adult AIS admissions in the United States from 2004 to 2014 were identified from the National Inpatient Sample (weighted n = 4,438,968). Multivariable-adjusted models were used to evaluate the association of AW with in-hospital medical complications, mortality, cost, and length of stay in patients with AIS.

RESULTS

Of the AA admissions, 10.6% of patients, representing 0.4% of all AIS, developed AW. The prevalence of AA and AW in AIS increased by 45.2% and 40.0%, respectively, over time (p for trend <0.001). Patients with AA were predominantly men (80.2%), white (65.9%), and in the 40- to 59-year (44.6%) and 60- to 79-year (45.6%) age groups. After multivariable adjustment, AIS admissions with AW had >50% increased odds of urinary tract infection, pneumonia, sepsis, gastrointestinal bleeding, deep venous thrombosis, and acute renal failure compared to those without AW. Patients with AW were also 32% more likely to die during their AIS hospitalization compared to those without AW (odds ratio 1.32, 95% confidence interval 1.11-1.58). AW was associated with ≈15-day increase in length of stay and ≈$5,000 increase in hospitalization cost (p < 0.001).

CONCLUSION

AW is associated with increased cost, longer hospitalizations, and higher odds of medical complications and in-hospital mortality after AIS. Proactive surveillance and management of AW may be important in improving outcomes in these patients.

Effect of Clinical Trial Experience on Transcatheter Aortic Valve Replacement Outcomes

BACKGROUND

Transcatheter aortic valve replacement (TAVR) was approved by the Food and Drug Administration (FDA) in November 2011 after a collaborative technology development process involving professional medical societies, the medical device industry, and the FDA. After FDA approval, TAVR was adopted by numerous hospitals that had not participated in TAVR clinical trials. It is uncertain if outcomes at these hospitals were comparable with those at clinical trial hospitals.

METHODS AND RESULTS

All patients with Medicare physician claims for TAVR between January 1, 2011, and November 30, 2012, were identified, and postoperative mortality was assessed using Medicare enrollment data. Risk-adjusted mortality was calculated via a multivariable model that adjusted for demographics and comorbidities. We identified 5009 patients who underwent TAVR, with 3617 TAVRs performed at 68 hospitals that had participated in clinical trials and 1392 TAVRs performed at 140 nontrial hospitals. The preoperative characteristics of patients at trial versus nontrial hospitals were similar. There were no significant differences in risk-adjusted 30-day mortality (5.9% versus 5.6%, odds ratio, 0.88; 95% confidence interval, 0.66-1.15; P=0.34) or 180-day mortality (16.5% versus 15.8%, odds ratio, 0.99; 95% confidence interval, 0.75-1.3; P=0.94).

CONCLUSIONS

Patients undergoing TAVR at nontrial hospitals had comparable clinical outcomes to patients undergoing TAVR at clinical trial hospitals. This finding contrasts with several other cardiovascular devices and procedures for which higher mortality was observed at hospitals that did not participate in clinical trials. The unique policy and regulatory environment governing TAVR adoption by hospitals may have contributed to better outcomes during the technology diffusion process.

Tranexamic Acid Use in United States Trauma Centers: A National Survey

Tranexamic acid (TXA) is an antifibrinolytic agent that is listed as an essential medication by the World Health Organization for traumatic hemorrhage. We determined United States–based surgeons’ familiarity with TXA and their use of TXA. An online survey was sent to the 1291 attending surgeon members of a national trauma organization. The survey was organized into three general parts: respondent demographics, perceptions of TXA, and experience with TXA. The survey was completed by 35 per cent of members. TXA was available at 89.1 per cent of centers. Experience with TXA was variable: 38.0 per cent use regularly, 24.9 per cent use it 1 to 2 times per year, 12.3 per cent use it rarely, and 24.7 per cent had never used it. Among surgeons who had used TXA, 77.1 per cent noted that TXA had reduced bleeding, but 22.9 per cent indicated that it had not. Reasons for not routinely using TXA included uncertain clinical benefit (47.7%) and unfamiliarity (31.5%). Finally, 90.5 per cent of respondents indicated that are looking toward national organizations to develop practice guidelines. TXA is widely available in civilian United States trauma centers. Although a majority of surveyed surgeons had used TXA, only 38 per cent use TXA regularly for significant traumatic hemorrhage; principal reasons for this are uncertainty regarding clinical benefit and unfamiliarity with the drug. National guidelines are sought.

Factors associated with length of hospitalization in patients admitted with transient ischemic attack in United States

BACKGROUND AND PURPOSE

Approximately 70% of all patients presenting with transient ischemic attack are admitted to the hospital in United States. The duration and cost of hospitalization and associated factors are poorly understood. This article seeks to identify the proportion and determinants of prolonged hospitalization and to determine the impact on hospital charges using nationally representative data.

METHODS

We determined the national estimates of length of stay, mortality, and charges incurred in patients admitted with transient ischemic attack (diagnosis-related code 524 or 069) using Nationwide Inpatient Sample data from 2002 to 2010. Nationwide Inpatient Sample is the largest all-payer inpatient care database in the United States and contains data from ≈1000 hospitals, which is a 20% stratified sample of US community hospitals. All the variables pertaining to hospitalization were compared in 3 groups on the basis of length of hospital stay (≤ 1, 2-6, and ≥ 7 days).

RESULTS

A total of 949 558 patients were admitted with the diagnosis of transient ischemic attack during the study period. The length of hospitalization was ≤ 1, 2 to 6, and ≥ 7 days in 232 732 (24.4%), 662 909 (70%), and 53 917 (5.6%) patients, respectively. The mean hospitalization charges were $10 876, $17 187, and $38 200 for patients hospitalized for ≤ 1, 2 to 6, and ≥ 7 days, respectively. The use of thrombolytics (0.03%, 0.09%, and 0.1%; P<0.0001) for ischemic stroke was very low among the 3 strata defined by length of hospitalization. In the multivariate analysis, the following factors were associated with length of hospitalization of ≥ 2 days: age >65 years (odds ratio [OR], 1.5), women (OR, 1.2), admission to teaching hospitals (OR, 1.1), renal failure (OR, 1.7), hypertension (OR, 1.1), diabetes mellitus (OR, 1.2), chronic lung disease (OR, 1.4), congestive heart failure (OR, 1.4), atrial fibrillation (OR, 1.5), ischemic stroke occurrence (OR, 1.4), Medicare/Medicaid insurance (OR, 1.3), and hospital location in Northeast US region (OR, 1.5; all P values <0.025).

CONCLUSIONS

Approximately 75% of patients admitted with transient ischemic attack stay in the hospital for ≥ 2 days, with the most important determinants being pre-existing medical comorbidities. Longer duration of hospital stay is associated with 2- to 5-fold greater hospitalization charges.