Influence of Arterial Occlusion on Outcome After Intravenous Thrombolysis for Acute Ischemic Stroke

Prolonged hospital length of stay in pediatric trauma: a model for targeted interventions

BACKGROUND

In this study, trauma-specific risk factors of prolonged length of stay (LOS) in pediatric trauma were examined. Statistical and machine learning models were used to proffer ways to improve the quality of care of patients at risk of prolonged length of stay and reduce cost.

METHODS

Data from 27 hospitals were retrieved on 81,929 hospitalizations of pediatric patients with a primary diagnosis of trauma, and for which the LOS was >24 h. Nested mixed effects model was used for simplified statistical inference, while a stochastic gradient boosting model, considering high-order statistical interactions, was built for prediction.

RESULTS

Over 18.7% of the encounters had LOS >1 week. Burns and corrosion and suspected and confirmed child abuse are the strongest drivers of prolonged LOS. Several other trauma-specific and general pediatric clinical variables were also predictors of prolonged LOS. The stochastic gradient model obtained an area under the receiver operator characteristic curve of 0.912 (0.907, 0.917).

CONCLUSIONS

The high performance of the machine learning model coupled with statistical inference from the mixed effects model provide an opportunity for targeted interventions to improve quality of care of trauma patients likely to require long length of stay.

IMPACT

Targeted interventions on high-risk patients would improve the quality of care of pediatric trauma patients and reduce the length of stay. This comprehensive study includes data from multiple hospitals analyzed with advanced statistical and machine learning models. The statistical and machine learning models provide opportunities for targeted interventions and reduction in prolonged length of stay reducing the burden of hospitalization on families.

Clinical Outcome of Patients With Large Vessel Occlusion and Low National Institutes of Health Stroke Scale Scores

Background and Purpose—

The treatment and prognosis of acute large vessel occlusion with mild symptoms have not been sufficiently studied. The present study aimed to investigate the clinical or radiological predictors of clinical outcome in patients with stroke with mild symptoms due to acute large vessel occlusion.

Methods—

Of 2420 patients with acute large vessel occlusion in the RESCUE-Japan Registry 2 (Recovery by Endovascular Salvage for Cerebral Ultra-Acute Embolism-Japan Registry 2), a multicenter prospective registry in Japan, patients with modified Rankin Scale scores of 0 to 2 before onset and initial National Institutes of Health Stroke Scale (NIHSS) scores of 0 to 5 were examined in post hoc analysis. We examined the clinical and radiological characteristics associated with a favorable outcome (modified Rankin Scale score, 0–2 at 90 days) using multivariate analysis, as well as the factors associated with a favorable outcome in patients treated with endovascular therapy.

Results—

We analyzed 272 patients (median age, 73 years; median NIHSS score on admission, 3). Eighty-six (31.6%) patients were treated with intravenous recombinant tissue-type plasminogen activator, 54 (19.9%) underwent endovascular therapy, and 208 (76.5%) showed a favorable outcome. In multivariate analysis, age <75 years (odds ratio [OR], 2.42 [95% CI, 1.30–4.50]), initial NIHSS score 0 to 3 (OR, 3.08 [95% CI, 1.59–5.98]), intravenous recombinant tissue-type plasminogen activator (OR, 2. 86 [95% CI, 1.32–6.21]), and blood glucose level ≤140 mg/dL (OR, 2.37 [95% CI, 1.22–4.60]) were independently associated with a favorable outcome. However, endovascular therapy was not associated with a favorable outcome (OR, 1.65 [95% CI, 0.71–3.88]). Among 54 patients treated with endovascular therapy, good reperfusion status was more common in the favorable outcome group (88.6% versus 60.0%; P <0.05).

Conclusions—

Younger age, lower initial NIHSS score, intravenous recombinant tissue-type plasminogen activator, and absence of hyperglycemia were independently associated with a favorable outcome in patients with acute large vessel occlusion with low NIHSS scores.

Registration—

URL: https://www.clinicaltrials.gov ; Unique identifier: NCT02419794.

Differential Benefit of Collaterals for Stroke Patients Treated with Thrombolysis or Supportive Care : A Propensity Score Matched Analysis

PURPOSE

Leptomeningeal collaterals can slow down infarction growth; however, despite good collaterals in the DAWN and DEFUSE 3 trials, outcomes were devastating if reperfusion was not attempted. The aim of this study was to compare the influence of collaterals on morphological and functional outcome in patients with acute middle cerebral artery (MCA) stroke undergoing intravenous thrombolysis (IVT) vs. supportive care (non-IVT).

METHODS

Out of 1639 consecutive patients examined with multiparametric computed tomography (CT) for suspected ischemic stroke, all patients with confirmed MCA stroke who did not undergo endovascular thrombectomy were selected. Propensity score matching (PSM) was used to match IVT and non-IVT treated patients for potential confounders including age, sex, National Institutes of Health Stroke Scale (NIHSS) score on admission, Alberta Stroke Program Early CT Score (ASPECTS), and occlusion site. Regression analysis after PSM was performed to identify independent associations.

RESULTS

After PSM, 90 IVT patients were matched with 90 non-IVT patients. In multivariable regression analysis, a high regional leptomeningeal collateral (rLMC) score was independently associated with lower final infarction volume (FIV) in the IVT group (b = -0.472, p < 0.001) but not in the non-IVT group (b = -0.116, p = 0.327). The trichotomized rLMC scores predicted functional outcome in IVT treated patients (adjusted odds ratio, aOR = 4.57, 95% confidence interval, CI, 1.03-20.32, p = 0.046) but showed no independent association with outcome in the non-IVT group (aOR = 0.69, 95% CI 0.07-6.80, p = 0.753).

CONCLUSION

Good collaterals favored smaller FIV and good functional outcome in IVT treated patients but not in non-IVT treated patients. Good collateral flow may have limited prognostic value if IVT is not administered to attempt reperfusion.

Intravenous Thrombolysis May Not Improve Clinical Outcome of Acute Ischemic Stroke Patients Without a Baseline Vessel Occlusion

Background and Purpose: The benefit of thrombolysis in ischemic stroke patients without a visible vessel occlusion still requires investigation. This study tested the hypothesis that non-lacunar stroke patients with no visible vessel occlusion on baseline imaging would have a favorable outcome regardless of treatment with alteplase. Methods: We utilized a prospectively collected registry of ischemic stroke patients [the International Stroke Perfusion Imaging Registry (INSPIRE)] who had baseline computed tomographic perfusion and computed tomographic angiography. The rates of patients achieving modified Rankin Scale (mRS) 0-1 were compared between alteplase treated and untreated patients using logistic regression to generate odds ratios. Results: Of 1569 patients in the INSPIRE registry, 1,277 were eligible for inclusion. Of these, 306 (24%) had no identifiable occlusion and were eligible for alteplase, with 141 (46%) of these patients receiving thrombolysis. The treated and untreated groups had significantly different median baseline National Institutes of Health Stroke Scale (NIHSS) [alteplase 8, interquartile range (IQR) 5-10, untreated 6, IQR 4-8, P < 0.001] and median volume of baseline perfusion lesion [alteplase 5.6 mL, IQR 1.3-17.7 mL, untreated 2.6 mL, IQR 0-6.7 mL, P < 0.001]. After propensity analysis, alteplase treated patients without a vessel occlusion were less likely to have an excellent outcome (mRS 0-1; 56%) than untreated (78.8%, OR, 0.42, 95% confidence interval, 0.24-0.75, P = 0.003). Conclusions: In this non-randomized comparison, alteplase treatment in patients without an identifiable vessel occlusion did not result in higher rates of favorable outcome compared to untreated. However, treated patients displayed less favorable baseline prognostic factors than the untreated group. Further studies may be required to confirm this data.

Impact of smoking on stroke outcome after endovascular treatment

Background

Recent studies suggest a paradoxical association between smoking status and clinical outcome after intravenous thrombolysis (IVT). Little is known about relationship between smoking and stroke outcome after endovascular treatment (EVT).

Methods

We analyzed data of all stroke patients treated with EVT at the tertiary stroke centre of Berne between January 2005 and December 2015. Using uni- and multivariate modeling, we assessed whether smoking was independently associated with excellent clinical outcome (modified Rankin Scale (mRS) 0–1) and mortality at 3 months. In addition, we also measured the occurrence of symptomatic intracranial hemorrhage (sICH) and recanalization.

Results

Of 935 patients, 204 (21.8%) were smokers. They were younger (60.5 vs. 70.1 years of age, p<0.001), more often male (60.8% vs. 52.5%, p = 0.036), had less often from hypertension (56.4% vs. 69.6%, p<0.001) and were less often treated with antithrombotics (35.3% vs. 47.7%, p = 0.004) as compared to nonsmokers. In univariate analyses, smokers had higher rates of excellent clinical outcome (39.1% vs. 23.1%, p<0.001) and arterial recanalization (85.6% vs. 79.4%, p = 0.048), whereas mortality was lower (15.6% vs. 25%, p = 0.006) and frequency of sICH similar (4.4% vs. 4.1%, p = 0.86). After correcting for confounders, smoking still independently predicted excellent clinical outcome (OR 1.758, 95% CI 1.206–2.562; p<0.001).

Conclusion

Smoking in stroke patients may be a predictor of excellent clinical outcome after EVT. However, these data must not be misinterpreted as beneficial effect of smoking due to the observational study design. In view of deleterious effects of cigarette smoking on cardiovascular health, cessation of smoking should still be strongly recommended for stroke prevention.

Effect of stroke thrombolysis predicted by distal vessel occlusion detection

OBJECTIVE

Among ischemic stroke patients with negative CT angiography (CTA), we aimed to determine the predictive value of enhanced distal vessel occlusion detection using CT perfusion postprocessing (waveletCTA) for the treatment effect of IV thrombolysis (IVT).

METHODS

Patients were selected from 1,851 consecutive patients who had undergone CT perfusion. Inclusion criteria were (1) significant cerebral blood flow (CBF) deficit, (2) no occlusion on CTA, and (3) infarction confirmed on follow-up. Favorable morphologic response was defined as smaller values of final infarction volume divided by initial CBF deficit volume (FIV/CBF). Favorable functional outcome was defined as modified Rankin Scale score of ≤2 after 90 days and decrease in NIH Stroke Scale score of ≥3 from admission to 24 hours (∆NIHSS).

RESULTS

Among patients with negative CTA (n = 107), 58 (54%) showed a distal occlusion on waveletCTA. There was no difference between patients receiving IVT (n = 57) vs supportive care (n = 50) regarding symptom onset, early ischemic changes, perfusion mismatch, or admission NIHSS score (all p > 0.05). In IVT-treated patients, the presence of an occlusion was an independent predictor of a favorable morphologic response (FIV/CBF: β -1.43; 95% confidence interval [CI] -1.96, -0.83; p = 0.001) and functional outcome (90-day modified Rankin Scale: odds ratio 7.68; 95% CI 4.33-11.51; p = 0.039; ∆NIHSS: odds ratio 5.76; 95% CI 3.98-8.27; p = 0.013), while it did not predict outcome in patients receiving supportive care (all p > 0.05).

CONCLUSION

In stroke patients with negative CTA, distal vessel occlusions as detected by waveletCTA are an independent predictor of a favorable response to IVT.

Reperfusion therapy in acute ischemic stroke: dawn of a new era?

Following the success of recent endovascular trials, endovascular therapy has emerged as an exciting addition to the arsenal of clinical management of patients with acute ischemic stroke (AIS). In this paper, we present an extensive overview of intravenous and endovascular reperfusion strategies, recent advances in AIS neurointervention, limitations of various treatment paradigms, and provide insights on imaging-guided reperfusion therapies. A roadmap for imaging guided reperfusion treatment workflow in AIS is also proposed. Both systemic thrombolysis and endovascular treatment have been incorporated into the standard of care in stroke therapy. Further research on advanced imaging-based approaches to select appropriate patients, may widen the time-window for patient selection and would contribute immensely to early thrombolytic strategies, better recanalization rates, and improved clinical outcomes.

Site and Rate of Occlusive Disease in Cervicocerebral Arteries: A CT Angiography Study of 2209 Patients with Acute Ischemic Stroke

BACKGROUND AND PURPOSE

CTA can rapidly and accurately detect and localize occlusive disease in patients with ischemic stroke. We have used CTA to assess arterial stenosis and occlusion in an ischemic stroke population arriving at a tertiary stroke center within 24 hours of symptom onset in order to obtain a comprehensive picture of occlusive disease pattern, and to determine the proportion of eligible candidates for endovascular treatment.

MATERIALS AND METHODS

Data from consecutive patients with acute ischemic stroke admitted to a single center between 2003 and 2012, collected in the Acute Stroke Registry and Analysis of Lausanne data base, were retrospectively analyzed. Patients with a diagnostic CTA within 24 hours of symptom onset were selected. Relevant extra- and intracranial pathology, defined as stenosis of ≥50% and occlusions, were registered and classified into 21 prespecified segments.

RESULTS

Of the 2209 included patients (42.1% women; median age, 72 years), 1075 (48.7%) had pathology in and 308 (13.9%) had pathology outside the ischemic territory. In the 50,807 arterial segments available for revision, 1851 (3.6%) abnormal segments were in the ischemic (symptomatic) territory and another 408 (0.8%) were outside it (asymptomatic). In the 1211 patients with ischemic stroke imaged within 6 hours of symptom onset, 40.7% had symptomatic large, proximal occlusions potentially amenable to endovascular therapy.

CONCLUSIONS

CTA in patients with acute ischemic stroke shows large individual variations of occlusion sites and degrees. Approximately half of such patients have no visible occlusive disease, and 40% imaged within 6 hours show large, proximal segment occlusions amenable to endovascular therapy. These findings show the importance of early noninvasive imaging of extra- and intracranial arteries for identifying occlusive disease, planning recanalization strategies, and designing interventional trials.

Arterial Obstruction on Computed Tomographic or Magnetic Resonance Angiography and Response to Intravenous Thrombolytics in Ischemic Stroke

BACKGROUND AND PURPOSE

Computed tomographic angiography and magnetic resonance angiography are used increasingly to assess arterial patency in patients with ischemic stroke. We determined which baseline angiography features predict response to intravenous thrombolytics in ischemic stroke using randomized controlled trial data.

METHODS

We analyzed angiograms from the IST-3 (Third International Stroke Trial), an international, multicenter, prospective, randomized controlled trial of intravenous alteplase. Readers, masked to clinical, treatment, and outcome data, assessed prerandomization computed tomographic angiography and magnetic resonance angiography for presence, extent, location, and completeness of obstruction and collaterals. We compared angiography findings to 6-month functional outcome (Oxford Handicap Scale) and tested for interactions with alteplase, using ordinal regression in adjusted analyses. We also meta-analyzed all available angiography data from other randomized controlled trials of intravenous thrombolytics.

RESULTS

In IST-3, 300 patients had prerandomization angiography (computed tomographic angiography=271 and magnetic resonance angiography=29). On multivariable analysis, more extensive angiographic obstruction and poor collaterals independently predicted poor outcome (P<0.01). We identified no significant interaction between angiography findings and alteplase effect on Oxford Handicap Scale (P≥0.075) in IST-3. In meta-analysis (5 trials of alteplase or desmoteplase, including IST-3, n=591), there was a significantly increased benefit of thrombolytics on outcome (odds ratio>1 indicates benefit) in patients with (odds ratio, 2.07; 95% confidence interval, 1.18-3.64; P=0.011) versus without (odds ratio, 0.88; 95% confidence interval, 0.58-1.35; P=0.566) arterial obstruction (P for interaction 0.017).

CONCLUSIONS

Intravenous thrombolytics provide benefit to stroke patients with computed tomographic angiography or magnetic resonance angiography evidence of arterial obstruction, but the sample was underpowered to demonstrate significant treatment benefit or harm among patients with apparently patent arteries.

CLINICAL TRIAL REGISTRATION

URL: http://www.isrctn.com. Unique identifier: ISRCTN25765518.

Impact of thrombolysis in acute ischaemic stroke without occlusion: an observational comparative study

BACKGROUND AND PURPOSE

The impact of intravenous recombinant tissue plasminogen activator (IV-rtPA) in patients with acute ischaemic stroke (AIS) but no arterial occlusion is currently a matter of debate. This study aimed to assess functional outcome of such patients with respect to IV-rtPA use.

METHODS

A retrospective case-control analysis was performed comparing the outcome of AIS patients without arterial occlusion with or without IV-rtPA use. Patients were selected from prospective consecutive observational registries of five European university hospitals. The primary study outcome was excellent outcome at 3 months after stroke, as defined by a modified Rankin Scale (mRS) 0-1.

RESULTS

A total of 488 patients without arterial occlusion documented by angiography were included in the present study; 300 received IV-rtPA and 188 did not. No between-group difference was found for excellent outcome before and after adjustment for baseline characteristics (adjusted odds ratio for no IV-rtPA use 0.79, 95% confidence interval 0.51-1.24, P = 0.31). Similar results were found for favourable outcome (defined as a 90-day mRS of 0-2) whereas a higher rate of early neurological improvement was found in IV-rtPA-treated patients (adjusted odds ratio 1.99; 95% confidence interval 1.29-3.07, P = 0.002). Sensitivity analyses yielded similar results.

CONCLUSIONS

Our study suggests that AIS patients without visible arterial occlusion treated with IV-rtPA may have no better outcome at 3 months than those untreated. However, only a randomized controlled trial would provide a definitive answer about the impact of rtPA in acute stroke patients without occlusion. Until then, these patients should be treated by rtPA as recommended.