Safety and efficacy of intravenous thrombolysis in stroke patients on prior antiplatelet therapy in the WAKE-UP trial

Predictive Factors for Hemorrhagic Transformation in Acute Ischemic Stroke in the REAL-World Clinical Practice

BACKGROUND

Few data exists on predictive factors of hemorrhagic transformation (HT) in real-world acute ischemic stroke patients. The aims of this study were: (i) to identify predictive variables of HT (ii) to develop a score for predicting HT.

METHODS

We retrospectively analyzed the clinical, radiographic, and laboratory data of patients with acute ischemic stroke consecutively admitted to our Stroke Unit along two years. Patients with HT were compared with those without HT. A multivariate logistic regression analysis was performed to identify independent predictors of HT on CT scan at 24 hours to develop a practical score.

RESULTS

The study population consisted of 564 patients with mean age 77.5±11.8 years. Fifty-two patients (9.2%) showed HT on brain CT at 24 hours (4.9% symptomatic). NIHSS score ≥8 at Stroke Unit admission (3 points), cardioembolic etiology (2 points), acute revascularization by systemic thrombolysis and/or mechanical thrombectomy (1 point), history of previous TIA/stroke (1 point), and major vessel occlusion (1 point) were found independent risk factors of HT and were included in the score (Hemorrhagic Transformation Empoli score (HTE)). The predictive power of HTE score was good with an AUC of 0.785 (95% CI: 0.749-0.818). Compared with 5 HT predictive scores proposed in the literature (THRIVE, SPAN-100, MSS, GRASPS, SITS-SIC), the HTE score significantly better predicted HT.

CONCLUSIONS

NIHSS score ≥8 at Stroke Unit admission, cardioembolism, urgent revascularization, previous TIA/stroke, and major vessel occlusion were independent predictors of HT. The HTE score has a good predictive power for HT. Prospective studies are warranted.

Sex Differences in Outcomes of Intravenous Thrombolysis in Acute Ischemic Stroke Patients with Preadmission Use of Antiplatelets

AIM

To compare safety and functional outcomes of intravenous thrombolysis (IVT) between females and males with acute ischaemic stroke (AIS) in relation to preadmission use of antiplatelets.

METHODS

Multicentre cohort study of patients admitted from 1 January 2014 to 31 January 2020 to hospitals participating in the Swiss Stroke Registry, presenting with AIS and receiving IVT. Primary safety outcome was in-hospital symptomatic intracerebral haemorrhage (sICH). Primary functional outcome was functional independence at 3 months after discharge. Multivariable logistic regression models were fitted to assess the association between sex and each outcome according to preadmission use of antiplatelets.

RESULTS

The study included 4996 patients (42.51 % females, older than males, median age 79 vs 71 years, p < 0.0001). Comparable proportions of females (39.92 %) and males (40.39 %) used antiplatelets before admission (p = 0.74). In total, 3.06 % females and 2.47 % males developed in-hospital sICH (p = 0.19), with similar odds (adjusted odds ratio, [AOR] 0.93, 95 % confidence interval, [CI] 0.63-1.39). No interaction was found between sex and preadmission use of either single or dual antiplatelets in relation to in-hospital sICH (p = 0.94 and p = 0.23). Males had higher odds of functional independence at 3 months (AOR 1.34, 95 % CI 1.09-1.65), regardless of preadmission use of antiplatelets (interaction between sex and preadmission use of either single or dual antiplatelets p = 0.41 and p = 0.58).

CONCLUSION

No sex differences were observed in the safety of IVT regarding preadmission use of antiplatelets. Males showed more favourable 3-month functional independence than females; however, this sex difference was apparently not explained by a sex-specific mechanism related to preadmission use of antiplatelets.

Hemorrhagic stroke during the acute phase of myocardial infarction: a rare and difficult situation to manage

Given the ischemic risk due to the hypercoagulability associated with acute coronary syndromes, the administration of antiplatelet and antithrombotic agents is necessary to prevent intracoronary and postprocedural thrombosis during percutaneous coronary interventions. However, the risk of bleeding, hemorrhagic stroke included, is real, although it has a lower prevalence, and it complicates the management of the coronary event if it happens. We report the case of a 66 years old patient with no prior pathological history who was initially admitted for acute coronary syndromes, complicated by paroxysmal atrial fibrillation that was successfully thrombolysed. Subsequently, the patient benefited from a drug-eluting stent angioplasty of the proximal circumflex artery, performed within 24 hours after the symptomatology onset. Following angioplasty, the patient presented with a left parietal intraparenchymal hematoma not indicating surgery. The double antiplatelet therapy was consequently withdrawn. Two days later, the patient presented with an ST-segment elevation infarction recurrence, inciting the resumption of the dual antiplatelet aggregation therapy. On evolution, the neurological state was still stable with a stationary aspect of the hematoma on cerebral imagery but without angina recurrence or electrocardiographic modifications. Hemorrhagic complications' occurrence following thrombolysis or angioplasty for ST-segment elevation infarction challenges the short and long-term management of the disease and must push practitioners to better weigh the risks and benefits before any medication administration decision.

Intravenous thrombolysis in patient with vertebrobasilar dolichoectasia and antiplatelet medication

Introduction: While the overall incidence of vertebrobasilar dolichoectasia (VBD) is less than 0.05%-0.06%, it is not uncommon in patients experiencing acute stroke. The influence of VBD on the outcome of intravenous (IV) thrombolysis therapy has not been widely studied. We present the following case of IV thrombolysis use in a patient experiencing acute stroke, who had an increased risk of bleeding due to prior antiplatelet use, and who had concomitant VBD. Case presentation: A 62-year-old man presented with weakness in the left extremities that had begun 1 hour prior to admission. The patient had a history of coronary artery disease and had been regularly taking antiplatelet medication. Upon arrival, the patient was in a decreased level of consciousness, with severe dysarthria, left central facial palsy, left lateralization, and a National Institute of Health Stroke Scale (NIHSS) score of 17. Computed tomography scan of the head showed no intracranial hemorrhage. The patient was administered IV thrombolysis at 2 hours and 45 minutes after symptom onset. Within the first 24 hours, the patient's NIHSS score decreased from 17 to 12, and the final NIHSS score prior to discharge was 7. The Head and neck angiography of this patient revealed VBD. Conclusion: This case demonstrated that IV thrombolysis is safe and effective for use in patients with acute ischemic stroke who have a history of antiplatelet usage and who experience concomitant VBD.

Intravenous thrombolysis for acute ischemic stroke: why not?

PURPOSE OF REVIEW

The aim of this study was to summarize available evidence regarding the safety and efficacy of intravenous thrombolysis (IVT) using recombinant tissue-plasminogen activator (rt-PA) in acute ischemic stroke (AIS) patients with specific comorbidities and potential contraindications to systemic reperfusion therapy. Recent advances in IVT implementation in wake-up stroke and in extended time window using advanced neuroimaging will also be highlighted.

RECENT FINDINGS

Despite theoretical concerns of a higher bleeding risk with IVT, there are no data showing increased risk of symptomatic intracerebral haemorrhage (sICH) in patients with stroke mimics, including seizures, increasing age and dual antiplatelet pretreatment. In addition, recent randomized evidence allows us to expand the time window of IVT for AIS using advanced neuroimaging both in wake-up stroke patients and in patients presenting within 4.5-9 h from symptom onset fulfilling certain neuroimaging criteria (based on DWI/FLAIR mismatch or perfusion mismatch).

SUMMARY

IVT is a highly effective systemic reperfusion therapy that counts 25 years of everyday clinical experience but still presents several challenges in its application. Appropriate patient selection and adherence to rt-PA protocol is paramount in terms of safety. The effort to simplify the indications, expand the therapeutic time window and eliminate specific initial contraindications is continuously evolving.

Development and external validation of a stability machine learning model to identify wake-up stroke onset time from MRI

OBJECTIVES

To develop and externally validate a machine learning (ML) model based on diffusion-weighted imaging (DWI) and fluid-attenuated inversion recovery (FLAIR) to identify the onset time of wake-up stroke from MRI.

METHODS

DWI and FLAIR images of stroke patients within 24 h of clear symptom onset in our hospital (dataset 1, n = 410) and another hospital (dataset 2, n = 177) were included. Seven ML models based on dataset 1 were developed to estimate the stroke onset time for binary classification (≤ 4.5 h or > 4.5 h): Random Forest (RF), support vector machine with kernel (svmLinear) or radial basis function kernel (svmRadial), Bayesian (Bayes), K-nearest neighbor (KNN), adaptive boosting (AdaBoost), and neural network (NNET). ROC analysis and RSD were performed to evaluate the performance and stability of the ML models, respectively, and dataset 2 was externally validated to evaluate the model generalization ability using ROC analysis.

RESULTS

svmRadial achieved the best performance with the highest AUC and accuracy (AUC: 0.896, accuracy: 0.878), and was the most stable (RSD% of AUC: 0.08, RSD% of accuracy: 0.06). The svmRadial model was then selected as the final model, and the AUC of the svmRadial model for predicting the onset time external validation was 0.895, with 0.825 accuracy.

CONCLUSIONS

The svmRadial model using DWI + FLAIR is the most stable and generalizable for identifying the onset time of wake-up stroke patients within 4.5 h of symptom onset.

KEY POINTS

• Machining learning model helps clinicians to identify wake-up stroke patients within 4.5 h of symptom onset. • A prospective study showed that svmRadial model based on DWI + FLAIR was the most stable in predicting the stroke onset time. • External validation showed that svmRadial model has good generalization ability in predicting the stroke onset time.