Stroke thrombectomy volume, rather than stroke center accreditation status of hospitals, is associated with mortality and discharge disposition

Characteristics of High-Performance Low-Volume Hospitals in Acute Stroke Care

BACKGROUND

High patient volumes are associated with better stroke management and outcomes. However, in sparsely populated regions, patients with stroke frequently rely on low-volume hospitals for acute care. This study evaluates the performance of high-performing hospitals among low-volume hospitals and identifies factors contributing to their high performance despite treating fewer stroke cases.

METHODS AND RESULTS

We analyzed data from the eighth Acute Stroke Quality Assessment Program in 2018, alongside reimbursement claims and death certificate records, to evaluate stroke care in 248 hospitals across South Korea, including all general and tertiary hospitals. The hospitals treating <100 patients with stroke annually were classified as low-volume. High performance among these hospitals was defined as achieving a defect-free care rate of >75%. The outcome measured was the poststroke 1-year mortality rate. Of 28 572 patients, 2521 (8.8%) were treated in low-volume hospitals, primarily general hospitals outside the capital area. The 1-year mortality rate was significantly higher in low-volume hospitals (24.8%) compared with their high-volume counterparts (17.6%, adjusted P<0.01). High-performing low-volume hospitals exhibited a significantly lower 1-year mortality rate (21.1%) than low-performing hospitals (26.9%, adjusted P=0.036), with no significant difference in the number of hospital beds or annual stroke admissions. High-performing low-volume hospitals were characterized by their location (P=0.048) and a significantly greater number of physicians, particularly neurologists (P=0.010). The presence of neurologists was also associated with a higher defect-free care rate in these hospitals.

CONCLUSIONS

This study highlights the status of low-volume hospitals in providing stroke care in areas with limited access to larger medical facilities. It suggests that enhancing acute stroke care performance, particularly through human resource investments, can significantly improve quality and patient outcomes at these hospitals.

Does Adding Thrombectomy-Capable Stroke Centers in a Regional Stroke Care System Affect Procedural Volume?

BACKGROUND

To maintain procedural proficiency and certification according to the standards set by The Joint Commission-which accredits health care centers in the United States-thrombectomy-capable stroke centers (TSCs) must achieve a minimum annual procedural volume. The addition of thrombectomy-capable centers in a regional stroke care system has the potential to increase access but also to decrease patient presentations and procedural volume at nearby centers. This study sought to characterize the impact of certifying additional thrombectomy-capable centers on procedural volume by center in a large, urban Emergency Medical Services (EMS) system.

METHODS

Data were collected from each designated thrombectomy-capable center in Los Angeles (LA) County from January 1, 2018 through June 30, 2022, during which a net total of five thrombectomy-capable centers were newly designated in the County. Per center volume for ischemic stroke presentations, intravenous (IV) thrombolysis administrations (IV tissue plasminogen activator [tPA]), and thrombectomy were tabulated by six-month interval. Median last-known-well-to-procedure times by LA County Public Health service planning area (SPA) were calculated. The effect of the number of designated centers on procedural volumes per center and median last-known-well-to-procedure times were analyzed via a linear mixed effects model with a log link function.

RESULTS

Procedural volume, ischemic stroke presentation volume, and last-known-well-to-procedure times had high variability over the time period studied. Nonetheless, the median values for each metric in this EMS system remained largely stable over the study period. There was no statistically significant association between the number of thrombectomy-capable centers and per center procedural volumes or times-to-procedure.

CONCLUSION

The designation of additional thrombectomy-capable centers in a regional stroke care system was not significantly associated with the volume of procedures by center or times-to-procedure, suggesting that additional centers may increase patient access to time-sensitive interventions without diluting patient presentations at existing centers.

Association of endovascular thrombectomy volume and outcomes in acute ischemic stroke: A National Inpatient Sample Study

BACKGROUND

Previous studies suggest a positive relationship between higher hospital endovascular thrombectomy (EVT) volume and improved outcomes. We investigated this association using the National Inpatient Sample (NIS) database from 2016 to 2020.

METHODS

A cross-sectional analysis of the NIS examined the relationship between hospital EVT volume and outcomes. Data on clinical and demographic variables were collected. Outcomes included favorable functional outcome (discharge home without assistance), inpatient mortality, and intracerebral hemorrhage (ICH). Hospitals in the top quintile of annual EVT volume were classified as high-volume centers. We conducted univariate, multivariate, nearest neighbor matched analysis, and an exploratory analysis to identify annual EVT volume cutoffs.

RESULTS

Among 114,640 patients with EVT, 24,415 (21.3%) were treated at high-volume centers. High-volume centers had higher rates of favorable functional outcomes in univariate (odds ratio (OR) 1.20, p < 0.001), multivariate (adjusted OR (aOR) 1.19, p = 0.003), and matched analysis (OR 1.14, p = 0.028). Before matching, inpatient mortality was lower in high-volume centers (OR 0.83, p < 0.001), but this difference was not significant in univariate and matched analyses. No differences in ICH were observed. Functional benefit was noted at ≥ 50 EVTs annually, with centers performing  ≥ 175 EVTs showing significantly higher benefits (aOR 1.42, p = 0.002).

CONCLUSIONS

Increased hospital EVT volume is associated with modestly improved functional outcomes in patients with acute ischemic stroke. Functional improvements are evident at ≥ 50 EVTs annually and increase with higher case volumes, without associated increases in inpatient mortality or ICH.

Higher proceduralist stroke thrombectomy volume is associated with reduced inpatient mortality

BACKGROUND

The aim of this study was to determine the impact of endovascular thrombectomy (EVT) proceduralist volume on in-hospital mortality in acute ischemic stroke (AIS) patients.

METHODS

We performed a retrospective cohort study using the 2020 Florida State Inpatient Database, including adult patients who had a diagnosis of AIS and underwent EVT during the same admission. The primary study outcome was in-hospital death. We used Youden's Index to define an optimal threshold for number of EVTs/year/provider. Based on this cut-point, the cohort was dichotomized into low and high proceduralist volume groups. We fit logistic regression models to mortality in the full cohort, both as univariate analyses and after adjusting for covariates.

RESULTS

Among 3143 AIS patients who underwent EVT, 1907 patients across 59 hospitals and 106 providers met our inclusion criteria. Among the providers, the median number of EVTs performed was 13.5 (IQR 7-25). The optimal cut-point was 17 EVTs. Demographics and comorbidities were similar between the cohorts. The high volume strata had a lower rate of in-hospital mortality (low volume 11.0% vs high volume 7.2%, P=0.005). After adjusting for potential confounders, high proceduralist volume remained significantly associated with lower odds of in-hospital death (OR 0.52, 95% CI 0.36 to 0.76, P=0.001). The difference in absolute risk of death was 4.8% (P=0.005).

CONCLUSIONS

We found that high proceduralist volume, defined by ≥18 EVTs/year, was associated with reduced in-hospital morality. Further research is necessary to understand the effects of proceduralist experience and benchmarks for technical proficiency in stroke care.

Modeling optimal patient transport in a stroke network capable of remote telerobotic endovascular therapy

BACKGROUND

Telerobotic endovascular therapy (EVT) has the potential to decrease time to treatment and expand existing networks of care to more rural populations. It is currently unclear how its implementation would impact existing stroke networks.

METHODS

Conditional probability models were generated to predict the probability of excellent outcome for patients with suspected large vessel occlusion (LVO). A baseline stroke network was created for California using existing intravenous thrombolysis (IVT) centers and comprehensive stroke centers (CSCs) capable of IVT and EVT. Optimal transport decisions and catchment areas were generated for the baseline model and three hypothetical scenarios through conversion of IVT centers at various distances from a CSC into centers capable of telerobotic EVT [i.e., hospitals ≥15 and <50 miles from a CSC were converted (Scenario 1), ≥50 and <100 miles (Scenario 2), and ≥100 miles (Scenario 3)]. Procedural times and success rates were varied systematically.

RESULTS

Telerobotic EVT centers decreased median travel time for LVO patients in all three scenarios. The estimated number of robotically treated LVOs per year in Scenarios 1, 2, and 3 were 2,172, 740, and 212, respectively. Scenario 1 (15-50 miles) was the most sensitive to robotic time delay and success rate, but all three scenarios were more sensitive to decreases in procedural success rate compared to time delay.

CONCLUSIONS

Telerobotic EVT has the potential to improve care for stroke patients outside of major urban centers. Compared to procedural time delays in robotic EVT, a decrease in procedural success rate would not be well tolerated.

Physician Transfer Versus Patient Transfer for Mechanical Thrombectomy in Patients With Acute Ischemic Stroke: A Systematic Review and Meta-Analysis

BACKGROUND

Physician transfer is an alternate option to patient transfer for expedient performance of mechanical thrombectomy in patients with acute ischemic stroke.

METHODS AND RESULTS

We conducted a systematic review to identify studies that evaluate the effect of physician transfer in patients with acute ischemic stroke who undergo mechanical thrombectomy. A search of PubMed, Scopus, and Web of Science was undertaken, and data were extracted. A statistical pooling with random-effects meta-analysis was performed to examine the odds of reduced time interval between stroke onset and recanalization, functional independence, death, and angiographic recanalization. A total of 12 studies (11 nonrandomized observational studies and 1 nonrandomized controlled trial) were included, with a total of 1894 patients. Physician transfer was associated with a significantly shorter time interval between stroke onset and recanalization with a pooled mean difference estimate of -62.08 (95% CI, -112.56 to -11.61]; P=0.016; 8 studies involving 1419 patients) with high between-study heterogeneity in the estimates (I2=90.6%). The odds for functional independence at 90 days were significantly higher (odds ratio, 1.29 [95% CI, 1.00-1.66]; P=0.046; 7 studies with 1222 patients) with physician transfer with low between-study heterogeneity (I2=0%). Physician transfer was not associated with higher odds of near-complete or complete angiographic recanalization (odds ratio, 1.18 [95% CI, 0.89-1.57; P=0.25; I2=2.8%; 11 studies with 1856 subjects).

CONCLUSIONS

Physician transfer was associated with a significant reduction in the mean of time interval between symptom onset and recanalization and increased odds for functional independence at 90 days with physician transfer compared with patient transfer among patients who undergo mechanical thrombectomy.

The evolution of acute stroke care in Germany from 2019 to 2021: analysis of nation-wide administrative datasets

BACKGROUND

The treatment of ischemic stroke (IS) has changed considerably in recent years. Particularly the advent of mechanical thrombectomy (MTE) has revolutionized the available treatment options. Most patients in developed countries have access to intravenous thrombolysis (IVT). However access to MTE remains restricted in some regions despite efforts to increase its availability. We performed an evaluation of national datasets to monitor improvements made in access to revascularization therapies for IS patients in Germany.

METHODS

We analyzed national datasets on German Diagnosis-Related Groups and structured quality reports by extracting information of patients admitted with stroke with and without IVT and MTE for the period of 2019-2021. Data from 2016 and limited data for 2022 were also included for comparison.

RESULTS

Admissions with ischemic stroke declined during the years of the COVID 19 pandemic by 4.5% from 227,258 in 2019 to 216,923 in 2021. IVT rates were stable with 16.3% being treated with IVT in 2019 and 2021. MTE rates continued to increase from 7.1 to 8.4% and the number of MTE centers increased by 14.8% in the same period. Over 87.3% of MTEs were performed in centers with a case volume exceeding 50 cases per year in 2021. The largest increase in the relative share of MTEs was seen in large MTE centers (n ≥ 200). Patient age for MTEs surpassed the age for IVTs in 2019 and the proportion of patients ≥ 80 years receiving MTE continued to increase. The proportion of regions in Germany with poor MTE rates (≤ 4.1%) decreased significantly from 2019 (12.3%) to 2021 (5.3%) (p < 0.001).

CONCLUSIONS

We found strong evidence that while IVT rates reached a temporary ceiling effect, both the absolute number of and access to MTEs continued to increase in Germany. Regional disparities have become less significant and the majority of MTEs are performed in centers with medium or high case volumes.

Telestroke network to robotic telestroke network: How to upgrade regional stroke care to include remote robotics?

Objective

Selected patients with large vessel occlusion (LVO) strokes can benefit from endovascular therapy (EVT). However, the effectiveness of EVT is largely dependent on how quickly the patient receives treatment. Recent technological developments have led to the first neurointerventional treatments using robotic assistance, opening up the possibility of performing remote stroke interventions. Existing telestroke networks provide acute stroke care, including remote administration of intravenous thrombolysis (IVT). Therefore, the introduction of remote EVT in distant stroke centers requires an adaptation of the existing telestroke networks. The aim of this work was to propose a framework for centers that are potential candidates for telerobotics according to the resources currently available in these centers.

Methods

In this paper, we highlight the future challenges for including remote robotics in telestroke networks. A literature review provides potential solutions.

Results

Existing telestroke networks need to determine which centers to prioritize for remote robotic technologies based on objective criteria and cost-effectiveness analysis. Organizational challenges include regional coordination and specific protocols. Technological challenges mainly concern telecommunication networks.

Conclusions

Specific adaptations will be necessary if regional telestroke networks are to include remote robotics. Some of these can already be put in place, which could greatly help the future implementation of the technology.

Higher Procedural Volumes Are Associated with Faster Treatment Times, Better Functional Outcomes, and Lower Mortality in Patients Undergoing Endovascular Treatment for Acute Ischemic Stroke

OBJECTIVE

We aimed to characterize the association of hospital procedural volumes with outcomes among acute ischemic stroke (AIS) patients undergoing endovascular therapy (EVT).

METHODS

This was a retrospective, observational cohort study using data prospectively collected from January 1, 2016 to December 31, 2019 in the Get with the Guidelines-Stroke registry. Participants were derived from a cohort of 60,727 AIS patients treated with EVT within 24 hours at 626 hospitals. The primary cohort excluded patients with pretreatment National Institutes of Health Stroke Scale (NIHSS) < 6, onset-to-treatment time > 6 hours, and interhospital transfers. There were 2 secondary cohorts: (1) the EVT metrics cohort excluded patients with missing data on time from door to arterial puncture and (2) the intravenous thrombolysis (IVT) metrics cohort only included patients receiving IVT ≤4.5 hours after onset.

RESULTS

The primary cohort (mean ± standard deviation age = 70.7 ± 14.8 years; 51.2% female; median [interquartile range] baseline NIHSS = 18.0 [13-22]; IVT use, 70.2%) comprised 21,209 patients across 595 hospitals. The EVT metrics cohort and IVT metrics cohort comprised 47,262 and 16,889 patients across 408 and 601 hospitals, respectively. Higher procedural volumes were significantly associated with higher odds (expressed as adjusted odds ratio [95% confidence interval] for every 10-case increase in volume) of discharge to home (1.03 [1.02-1.04]), functional independence at discharge (1.02 [1.01-1.04]), and lower rates of in-hospital mortality (0.96 [0.95-0.98]). All secondary measures were also associated with procedural volumes.

INTERPRETATION

Among AIS patients primarily presenting to EVT-capable hospitals (excluding those transferred from one facility to another and those suffering in-hospital strokes), EVT at hospitals with higher procedural volumes was associated with faster treatment times, better discharge outcomes, and lower rates of in-hospital mortality. ANN NEUROL 2023.