Best Practice Recommendations for Stroke Vascular Imaging During Iodinated Contrast Shortage

GE Healthcare© announced on April 19, 2022, that their main factory and distributor of iodinated contrast had experienced a temporary shutdown because of COVID-19 outbreak in Shanghai, China. This, along with other supply chain issues, led to a worldwide shortage of iodinated contrast agents, Omnipaque and Visipaque. Our Comprehensive Stroke Center was confronted with the cascading effect of this iodinated contrast material shortage. We took immediate steps to revise our protocols and processes to continue to provide high-quality care to our stroke patients. A multidisciplinary working group comprised of representatives of our stroke center, including vascular neurology, diagnostic neuroradiology, and neurovascular surgery, urgently met to brainstorm how to mitigate the shortage. We established parameters and local guidelines for the use of CT angiography, CT perfusion, and digital subtraction angiography for stroke patients. In this article, we propose "best practice" recommendations from a single Joint Commission approved Comprehensive Stroke Center that can be used as blueprint by other hospital systems when navigating potential future supply chain issues, to provide consistent high-quality stroke care.

Predictors of early neurologic deterioration (END) following stroke thrombectomy

BACKGROUND

Early neurologic deterioration (END) following ischemic stroke is a serious event and is associated with poor outcomes. However, the incidence and predictors of END after stroke thrombectomy for emergent large vessel occlusion are largely unknown.

METHODS

The baseline characteristics of patients enrolled in the COMPASS trial (NCT02466893) were analyzed. The primary outcome was worsening of ≥4 National Institutes of Health Stroke Scale (NIHSS) points 24 hours post thrombectomy (4+ END₂₄) and the secondary outcome was deterioration of ≥2 points (2+ END₂₄).

RESULTS

Among 270 patients, 27 (10%) developed 4+ END₂₄ and 42 (16%) had 2+ END₂₄. Those with 4+ END₂₄ were older (76.4±12.9 vs 70.9±12.9 years; p=0.04), had a higher prevalence of hypertension (96% vs 69%; p=0.003), diabetes (41% vs 27%; p=0.13) and higher pretreatment systolic blood pressure (SBP) (170.4±32.6 vs 157.6±28.1 mmHg; p=0.03). More 4+ END₂₄ patients had failed reperfusion: Thrombolysis in Cerebral Infarction ≤2a (26% vs 8%; p=0.003). In unadjusted analysis, older patients and those with hypertension, diabetes, elevated SBP and failed reperfusion had higher odds of 4+ END₂₄. In adjusted analysis, age increase by 5 years led to an increase in 4+ END₂₄ of 28%, diabetes increased odds of 2.6 and failed reperfusion increased odds of 4.5. In the multivariable analysis for the secondary outcome, age (OR 1.33; 95% CI 1.109 to 1.593), diabetes (OR 2.7; 95% CI 1.247 to 5.764) and failed reperfusion (OR 7.2; 95% CI 0.055 to 0.349) were also significant predictors of 2+ END₂₄.

CONCLUSIONS

Older patients with acute ischemic stroke who have a history of diabetes or hypertension, with elevated pretreatment SBP and failed reperfusion are at a higher risk of END following stroke thrombectomy for emergent large vessel occlusion.

Prospective Interventions to Reduce Stroke Care Variation in a Hub-and-Spokes System

BACKGROUND

Care variation reduction (CVR) is a central objective of quality management to decrease wasted spending.

OBJECTIVE

To analyze stroke care variation at a hub-and-spokes system and determine interventions to prospectively reduce unwarranted variation.

METHODS

In this prospective cohort single arm intervention study providers were blinded to pre-specified endpoints. Care variation was measured for DRGs 61-66 and 69 in USD, and severity level by Case Mix Index (CMI) by provider. A multi-disciplinary task force chaired by Vascular Neurologist analyzed data extracted from Crimson, a patient centric data analysis tool, and determined interventions. The primary measure outcome was change in CMI post intervention.

RESULTS

Annualized baseline care variation was $ 0.7-1.2M (2017) in a drip-and-ship thrombolytic treatment model within the hub-and-spokes system. Pharmacy expenses contributed to 42% of variation followed by laboratory 12%, physical therapy 11%, supplies 11% and imaging 9%. Interventions to achieve CVR were prospectively implemented in 2018 and CVR was measured in January 2019. Based on 2017 CMI of 1.28, the goal of intervention was set to achieve 7% increase to 1.37 with projected increased revenue of $774,144. After implementation of interventions the actual achieved average CMI in 2018 was 1.40 paralleled by improvement in secondary outcomes of length of stay, observed over expected mortality and re-admission.

CONCLUSIONS

A drip-and-ship stroke model within a single hub-and-spokes healthcare system can achieve substantial reduction in care variation and associated cost along with improvement in patient care indicators.

Impact of a Pharmacist-Driven Poststroke Transitions of Care Clinic on 30 and 90-Day Hospital Readmission Rates

BACKGROUND

Stroke impacts nearly 800,000 people annually and the risk of recurrent stroke and hospital readmission is increased early following the initial event. Due to the increase in morbidity and mortality associated with secondary events, a pharmacist-driven poststroke transitions of care clinic was created at Methodist University Hospital to provide risk factor modification in an effort to decrease risk of recurrence and hospital readmissions.

METHODS

A retrospective matched-cohort study was conducted between 9/1/2017 and 2/28/2019. Adult patients with a primary diagnosis of stroke, discharged to home, and attended a poststroke transitions of care clinic visit were included. Patients were matched on the basis of age ±3 years, race, gender, and type of stroke to those who did not receive pharmacist intervention during the same time period. The primary endpoint was 30-day hospital readmissions. Secondary endpoints included 90-day readmissions, 30 and 90-day emergency department visits, and recurrent stroke rates. Type and quantity of pharmacist interventions was also assessed.

RESULTS

One hundred and eighty-eight patients were included in the analysis. Baseline differences existed between the groups in the following: history of transient ischemic attack, stroke severity score, and insurance status. No significant difference was found in 30-day readmissions. There was a significant difference found in 90-day readmissions (5.3% versus 21.3%, P = .001). There were no significant differences in emergency department utilization at 30 or 90 days or stroke recurrence rates. Pharmacists made a mean of 3.5 interventions made during each visit.

CONCLUSIONS

Although the primary goal to reduce 30-day readmission was not met, a pharmacist-driven poststroke transitions of care clinic significantly decreased 90-day hospital readmission rates.

Cryptogenic Stroke and Significance of the Patent Foramen Ovale: A Case Series

Stroke is the second leading cause of death globally and can lead to significant adverse outcomes in patients following the acute illness. Due to this high morbidity and mortality, adequate interventions can play a significant role in health outcomes. Patent foramen ovale is one of the major proposed causes of cryptogenic strokes and can be present in up to 25% of general population. In cryptogenic strokes, the relation of this structural heart defect is inversely proportional to age of patient. Here, we present three cases of cryptogenic strokes in patients with patent foramen ovale where it possibly plays a significant role. We demonstrate that in the younger age spectrum, patent foramen ovale plays a more significant role and treatment could prevent future stroke episodes.

Abstract TMP6: A Multi-center Study of Safety and Efficacy of Mechanical Thrombectomy for Acute Ischemic Stroke Patients with Emergent Large Vessel Occlusions Not Meeting Top Tier Evidence Criteria

Background: Recent recommendations for mechanical thrombectomy (MT) of acute ischemic stroke (AIS) patients with emergent large-vessel occlusions (ELVO) appropriately award top tier evidence (TTE) to the same selective criteria that were employed in recent clinical trials. We sought to evaluate the safety and efficacy of MT in AIS patients with ELVO who fail TTE criteria in a prospective multi-center study.

Methods: Data on consecutive AIS patients with ELVO who underwent mechanical thrombectomy were collected from 6 high-volume endovascular centers. Standard safety and efficacy outcomes were compared between patients meeting and failing TTE criteria.

Results: TTE criteria for MT were fulfilled in 349 (60%) cases (mean age 63±18 years; 47% men; median admission NIHSS-score 17 points, interquartile range 14-21), whereas 234 (40%) patients did not meet TTE criteria (mean age 62±19 years; 53% men; median admission NIHSS-score 16 points, interquartile range 9-21). (Table 1) The two most common reasons for failing TTE criteria were location of intracranial occlusion (n=144) and treatment window (n=108). In multivariate logistic regression models adjusting for potential confounders cases failing TTE criteria had similar safety (three-month mortality and symptomatic intracranial hemorrhage) and efficacy (three-month functional independence) outcomes with patients meeting TTE. Location of occlusion and proposed time-window according to TTE was also not related to any safety or efficacy outcome. (Table 2)

Conclusions: Approximately 40% of AIS patients with ELVO offered MT do not fulfill TTE criteria for MT. Our multi-center experience indicates that MT may be offered to these patients with similar safety and efficacy to ELVO cases meeting TTE. Evidence-based medicine requires that health care providers understand published data and how those data might apply to a given patient’s treatment options. In a changing treatment environment this is a dynamic process.

The value of transesophageal echocardiography for embolic strokes of undetermined source

OBJECTIVE

Our aim was to evaluate the diagnostic yield of transesophageal echocardiography (TEE) in consecutive patients with ischemic stroke (IS) fulfilling the diagnostic criteria of embolic strokes of undetermined source (ESUS).

METHODS

We prospectively evaluated consecutive patients with acute IS satisfying ESUS criteria who underwent in-hospital TEE examination in 3 tertiary care stroke centers during a 12-month period. We also performed a systematic review and meta-analysis estimating the cumulative effect of TEE findings on therapeutic management for secondary stroke prevention among different IS subgroups.

RESULTS

We identified 61 patients with ESUS who underwent investigation with TEE (mean age 44 ± 12 years, 49% men, median NIH Stroke Scale score = 5 points [interquartile range: 3-8]). TEE revealed additional findings in 52% (95% confidence interval [CI]: 40%-65%) of the study population. TEE findings changed management (initiation of anticoagulation therapy, administration of IV antibiotic therapy, and patent foramen ovale closure) in 10 (16% [95% CI: 9%-28%]) patients. The pooled rate of reported anticoagulation therapy attributed to abnormal TEE findings among 3,562 acute IS patients included in the meta-analysis (12 studies) was 8.7% (95% CI: 7.3%-10.4%). In subgroup analysis, the rates of initiation of anticoagulation therapy on the basis of TEE investigation did not differ (p = 0.315) among patients with cryptogenic stroke (6.9% [95% CI: 4.9%-9.6%]), ESUS (8.1% [95% CI: 3.4%-18.1%]), and IS (9.4% [95% CI: 7.5%-11.8%]).

CONCLUSIONS

Abnormal TEE findings may decisively affect the selection of appropriate therapeutic strategy in approximately 1 of 7 patients with ESUS.

Implications of limiting mechanical thrombectomy to patients with emergent large vessel occlusion meeting top tier evidence criteria

BACKGROUND

Recent guidelines for endovascular management of emergent large vessel occlusion (ELVO) award top tier evidence to the same selective criteria in recent trials. We aimed to understand how guideline adherence would have impacted treatment numbers and outcomes in a cohort of patients from a comprehensive stroke center.

METHODS

A retrospective observational study was conducted using consecutive emergent endovascular patients. Mechanical thrombectomy (MT) was performed with stent retrievers or large bore clot aspiration catheters. Procedural outcomes were compared between patients meeting, and those failing to meet, top tier evidence criteria.

RESULTS

126 patients receiving MT from January 2012 to June 2015 were included (age 31-89 years, National Institutes of Health Stroke Scale (NIHSS) score 2-38); 62 (49%) patients would have been excluded if top tier criteria were upheld: pretreatment NIHSS score <6 (10%), Alberta Stroke Program Early CT score <6 (6.5%), premorbid modified Rankin Scale (mRS) score ≥2 (27%), M2 occlusion (10%), posterior circulation (32%), symptom to groin puncture >360 min (58%). 26 (42%) subjects had more than one top tier exclusion. Symptomatic intracerebral hemorrhage (sICH) and systemic hemorrhage rates were similar between the groups. 3 month mortality was 45% in those lacking top tier evidence compared with 26% (p=0.044), and 3 month mRS score 0-2 was 33% versus 46%, respectively (NS). After adjusting for potential confounders, top tier treatment was not associated with neurological improvement during hospitalization (β -8.2; 95% CI -24.6 to -8.2; p=0.321), 3 month mortality (OR=0.38; 95% CI 0.08 to 1.41), or 3 month favorable mRS (OR=0.97; 95% CI 0.28 to 3.35).

CONCLUSIONS

Our study showed that with strict adherence to top tier evidence criteria, half of patients may not be considered for MT. Our data indicate no increased risk of sICH and a potentially higher mortality that is largely due to treatment of patients with basilar occlusions and those treated at an extended time window. Despite this, good functional recovery is possible, and consideration of MT in patients not meeting top tier evidence criteria may be warranted.

Abstract TP218: Transoesophageal Echocardiography in the Diagnostic Work-up of Patients With Embolic Stroke of Undetermined Source: A Necessary Investigation That Should Not Be Overlooked

Background&Purpose: The currently proposed criteria for the definition of embolic strokes of undetermined source (ESUS) do not include investigation with transesophageal echocardiography (TEE) among the mandatory diagnostic work-up. We sought to evaluate the diagnostic yield of TEE in consecutive patients fulfilling ESUS criteria.

Methods: We prospectively evaluated ischemic stroke (IS) patients fulfilling ESUS criteria from three tertiary care stroke centers during a twelve month period. All patients underwent additional diagnostic work-up with TEE to estimate both the diagnostic yield and the impact of TEE findings in the therapeutic management of patients with ESUS.

Results: We identified 61 patients with ESUS who underwent investigation with TEE [mean age 44.3±11.5 years; 49.2% males; median NIHSS=5 (IQR, 3-8)]. TEE revealed additional findings in 52.4% (95%CI by the adjusted Wald method: 40.2%-64.5%) of the patients. Patent foramen ovale (PFO) and atrial septal aneurysm (ASA) were reported in 27.8% (95%CI: 18.1%-40.2%) and 13.1% (95%CI: 6.5%-24.1%) of the study population respectively. The concurrence of PFO and ASA was reported in 4 patients (6.5%, 95%CI: 2.1%-16.1%). The presence of valvular vegetations was documented in 2 patients (3.2%; 95%CI: 0%-11.8%), while thrombus was found in the left atrium of one patient (1.6%, 95%CI: 0%-9.5%). Complex aortic arch atheromatosis was reported in 6.5% (95%CI: 2.1%-16.1%) of the patients. Neither myxomas, nor ventricular septal defects were found in TEE examinations. TEE findings changed the management in 16.4% (95%CI: 8.9%-27.8%) of the patients. Anticoagulants were initiated in 5 patients, while the other 2 patients with endocarditis received treatment with intravenous antibiotics. Finally, 3 of the 61 patients underwent a PFO-closure procedure due to the large size of the shunt and the previous history of recurrent cryptogenic IS.

Conclusions: Our findings suggest that ESUS patients should undergo investigation with TEE in search of potential cardioembolic or aortogenic sources. TEE findings may have a decisive impact on the selection of the appropriate therapeutic approach for these patients.

Abstract 135: Heart Failure and the Risk of Ischemic Stroke Recurrence: A Systematic Review and Meta-analysis

Background & Purpose: Heart failure (HF) is a major risk factor for thromboembolism and first-ever stroke, and is associated with greater stroke severity and higher rates of early mortality and residual disability. There are limited data regarding the association of HF with stroke recurrence. We sought to evaluate the relationship between HF and recurrent IS stroke using a comprehensive meta-analytical approach.

Methods: We performed a systematic literature review according to PRISMA guidelines to identify all prospective study protocols (randomized clinical trials or observational cohorts) that reported rates of IS recurrence in patients with concomitant HF. We pooled independently the reported corresponding risk ratios (RRs) and hazard ratios (HRs) from each study protocol using the random effects model.

Results: Our literature search identified 7 eligible studies including 9,173 IS patients (18.2% with HF). The reported mean follow-up period in the included studies ranged from 7 days to 5 years. The pooled estimate of RRs and HRs for recurrent IS was 1.96 (95%CI: 1.49-2.60; p<0.0001; Figure, Caption A) and 1.93 (95%CI: 1.47-2.53; p<0.0001 Figure, Caption B). We found no evidence of heterogeneity within studies in both the RR (I2=13.5%, p for Cochran Q statistic: 0.325) and HR (I2=0%, p for Cochran Q statistic: 0.629) analyses.

Conclusions: HF is associated with a continuous two-fold increase in the risk of IS recurrence in patients with prior history of cerebral ischemia. The benefit of anticoagulation in this high-risk group of patients may be studied along with additional risk factor modifications.

Abstract T MP49: Should Transesophageal Echocardiography (TEE) be the Initial Diagnostic Modality of Choice in Young Ischemic Stroke (IS) Patients?

Background&Purpose: Current data is limited regarding the comparative utility of Transthoracic echocardiography (TTE) vs. TEE in diagnosing potential sources of cardioembolism (PSOC) in patients with cryptogenic stroke, particularly in young stroke patients. We sought to evaluate the comparative diagnostic yield of these two echocardiographic modalities in young IS patients.

Methods: We conducted a retrospective chart review of consecutive young (18-45 yrs) IS patients admitted to a tertiary care stroke center over a study period of 42 months. All patients underwent both TTE and TEE during their standard diagnostic work-up. Stroke classification at discharge was performed according to TOAST criteria by treating physicians.

Results: The study population consisted of 83 IS patients (mean age 38±5years, 40% men, 86% blacks, median admission NIHSS-score 3 points, IQR 1-8) who underwent both echocardiographic examinations. Cardioembolic stroke (CS) was the discharge diagnosis in 22 cases (27%). EF calculated by TEE strongly correlated to EF calculated by TTE (r=0.846; p<0.001). Left atrial enlargement was detected more frequently by TEE than TTE (27% vs. 11%; p<0.001). The overall yield of TEE for detecting PSOC was higher than TTE (23% vs 4%; p=0.011). TTE diagnosis of a PSOC was not associated with CS discharge diagnosis in univariate analyses (OR: 6.0, 95%CI: 0.5-69.8; p=0.152). TEE diagnosis of PSOC was associated with CS in univariate analyses (OR: 13.2, 95%CI: 4.0-43.8; p<0.0001). After adjustment for demographics, vascular risk factors, admission NIHSS-score, admission SBP and DBP levels, admission blood glucose and abnormal TTE, TEE diagnosis of a PSOC was independently associated with a higher likelihood of CS diagnosis at hospital discharge (OR: 24.3, 95%CI: 5.9-100.0; p<0.0001).

Conclusions: Our study showed that the yield of TEE for detecting PSOC was higher than that of TTE, while abnormal TEE findings were independently associated with a higher likelihood of CS diagnosis. TEE should be considered as the initial echocardiographic modality for evaluating young IS patients, since it may expedite workup and early detection of stroke etiopathogenic mechanism.

Quadriceps tendon ruptures in uremia

Chronic renal failure and its sequelae, particularly secondary hyperparathyroidism, may be associated with spontaneous quadriceps tendon ruptures. This is a report of two cases of bilateral spontaneous simultaneous quadriceps tendon ruptures in uremia and a review of the literature. The level at which the tendon ruptures is inconstant. Light microscopy reveals nonspecific changes of degeneration and calcification. Under electron microscopy, the structure and maturity of collagen fibers are normal. The ruptures occur in patients younger than 40 years of age who reject medical treatment (i.e. oral phosphate binder) and have long-standing renal disease (mean = 12.3 years). The predisposing causes of rupture are unknown. An abnormality of collagen metabolism, ischemia, direct effects of parathormone, and dystrophic calcification are some of the possible contributory factors.

Bilateral simultaneous spontaneous rupture of quadriceps tendons in a diabetic patient

We have described a case of bilateral simultaneous spontaneous quadriceps tendon rupture. The diagnosis is established by clinical examination. Definitive treatment consists of surgical repair followed by cylinder cast application for six to eight weeks.

Two-level thoracic disc herniation

Herniation of thoracic discs at T6-7 and T7-8 occurred in a 41-year-old man. Thoracic disc disease is rare and the present case could be the first two-level herniation reported in the literature. The diagnosis was established by a myelogram (metrizamide) and computed tomographic (CT) scanning. The herniated discs were excised through a posterolateral approach. The preferred exposure is either translateral or transthoracic. Laminectomy is contraindicated, as it fails to correct spinal cord hemodynamics or relieve axial tension in the presence of an anterior epidural obstruction.