Thrombolytic-Related Asymptomatic Hemorrhagic Transformation Does Not Deteriorate Clinical Outcome: Data from TIMS in China

Clinically Asymptomatic Hemorrhagic Conversion Is Associated with Need for Inpatient Rehabilitation After Mechanical Thrombectomy for Anterior Circulation Ischemic Stroke

BACKGROUND

Hemorrhagic conversion (HC) is a known complication after acute ischemic stroke (AIS) in patients undergoing mechanical thrombectomy (MT). Although symptomatic HC has been shown to lead to poor neurologic outcomes, the effect of asymptomatic HC (aHC) is unclear. This study aims to identify predictors of aHC and to determine the short-term outcomes.

METHODS

This is a single-institution retrospective study of patients with anterior circulation stroke (AIS) who underwent MT between January 2016 and September 2022. Radiographic HC was identified on postoperative imaging. Asymptomatic hemorrhage was defined as no acute neurologic decline attributable to imaging findings. Baseline characteristics, technical aspects, and outcomes were compared between aHC and no-HC groups. Logistic regression and multivariate analysis were performed.

RESULTS

A total of 615 patients underwent MT for AIS, of whom 496 met the inclusion criteria. A total of 235 patients (47.4%) had evidence of aHC. Diabetes mellitus (odds ratio [OR], 1.59; 95% confidence interval [CI], 1.06-2.41; P = 0.03), hyperglycemia (OR, 1.01; 95% CI, 1.00-1.01; P = 0.002), greater number of passes (OR, 1.14; 95% CI, 1.00-1.31; P = 0.05), and longer time to reperfusion (OR, 1.02; 95% CI, 1.00-1.05; P = 0.05) were associated with aHC. Patients with aHC were significantly more likely to require rehabilitation, whereas those without HC were more likely to be discharged home (P < 0.001). There were no significant differences in long-term outcomes.

CONCLUSIONS

HC occurred in up to half of patients who underwent MT for AIS, most of whom were clinically asymptomatic. Despite clinical stability, aHC was significantly associated with a greater need for inpatient rehabilitation. Predictors of aHC included hyperglycemia and a longer time to reperfusion.

Prognostic significance of the clinical and radiological haemorrhagic transformation subtypes in acute ischaemic stroke: A systematic review and meta-analysis

BACKGROUND AND PURPOSE

The aim was to investigate the associations of haemorrhagic transformation (HT) and its clinical and radiological subtypes with functional outcome, mortality, early neurological deterioration (END) and neurological complications in patients with acute ischaemic stroke (AIS).

METHODS

A systematic review and meta-analysis of observational studies on the associations of overall HT, clinical HT subtypes (asymptomatic intracerebral haemorrhage [aICH] and symptomatic intracerebral haemorrhage [sICH]) or radiological HT subtypes (haemorrhagic infarction [HI-1 or HI-2] and parenchymal haemorrhage [PH-1 or PH-2]) with prognosis in patients with AIS was performed. PubMed, Web of Science and Embase were systematically searched. Random effects models were used to calculate pooled estimates.

RESULTS

Fifty-one studies with 100,510 patients were pooled in the meta-analysis. Overall HT was associated with worse functional outcome (odds ratio [OR] 2.12, 95% confidence interval [CI] 1.55-2.90), increased mortality (OR 1.87, 95% CI 1.52-2.30), END (OR 2.35, 95% CI 1.46-3.77), early-onset seizures (OR 2.58, 95% CI 1.63-4.10) and post-stroke epilepsy (OR 2.23, 95% CI 1.11-4.49). For clinical subtypes, sICH remained significantly associated with the aforementioned poor prognoses except post-stroke epilepsy, and aICH was associated with worse functional outcome but was unrelated to mortality. For radiological subtypes, PH (especially PH-2) was strongly associated with poor prognosis. HI-2 was associated with worse functional outcome, and HI-1 was associated with a lower risk of mortality and END.

CONCLUSIONS

Regardless of whether AIS patients undergo thrombolysis or thrombectomy, overall HT, sICH and PH (especially PH-2) are associated with a substantially increased risk of worse functional outcome, mortality, END or neurological complications. The presence of aICH is related to worse functional outcome but is independent of increased mortality. HI-2 impairs functional independence, and HI-1 does not cause neurological impairment.

Prognosis associated with asymptomatic intracranial hemorrhage after acute ischemic stroke: a systematic review and meta-analysis

BACKGROUND AND PURPOSE

It remains inconclusive whether asymptomatic intracranial hemorrhage (aICH) after acute ischemic stroke is innocuous. We aimed to conduct a meta-analysis assessing the relationship between the aICH and poor neurological outcomes.

METHODS

We searched PubMed, EMBASE and Web of Science from their inception to 30 November 2021 and performed a meta-analysis on the association between the aICH and neurological prognosis after acute ischemic stroke at 3 months, including poor outcomes (modified Rankin Scale [mRS] score ≥ 2 or mRS ≥ 3) and mortality.

RESULTS

Fourteen studies were included in the analysis, reporting on a total of 10,915 participants after acute ischemic stroke. The risks of poor outcome (mRS ≥ 2 or mRS ≥ 3) in patients with aICH were significantly higher than patients without ICH (OR 1.70, 95% CI 1.33-2.18; OR 1.43, 95% CI 1.20-1.70, respectively), based on adjusted data. The difference between the two groups was not significant for mortality. The results of subgroup analysis showed aICH were associated with higher ratio of mild poor prognosis (mRS ≥ 2) (OR 1.59, 95% CI 1.11-2.27), but it had no association with functional dependence (mRS ≥ 3) after recanalization. No significant influence of aICH on poor outcome (mRS ≥ 3) was found in non-recanalization group. Further stratified analysis revealed that only aICH with patients receiving endovascular therapy (EVT) could increase the risk of mild poor prognosis (mRS ≥ 2) at 3 months.

CONCLUSIONS

Our results indicate that compared with patients without ICH, those who developed aICH during the acute stage of ischemic stroke had an increasing risk of worse outcome, especially in patients with endovascular therapy.

Hemorrhagic Transformation in Acute Ischemic Stroke: A Quantitative Systematic Review

The prevalence and risk factors of hemorrhagic transformation (HT) after acute ischemic stroke HT have not been adequately delineated. We performed a systematic review and meta-analysis to identify English-language prospective observational MEDLINE and EMBASE-listed reports of acute ischemic stroke with HT published from 1985–2017. Studies that used the ECASS-2 definitions of hemorrhagic transformation subtypes, hemorrhagic infarction (HI), and parenchymal hematoma (PH) were included. Patients treated with intravenous thrombolysis with tissue plasminogen activator (IV-tPA) were compared with those who did not receive thrombolysis. A total of 65 studies with 17,259 patients met inclusion criteria. Overall, HT prevalence was 27%; 32% in patients receiving IV-tPA vs. 20% in those without. Overall PH prevalence was 9%; 12% in IV-tPA treated patients vs. 5% in those without. HT was associated with a history of atrial fibrillation (OR 2.94) and use of anticoagulants (OR 2.47). HT patients had higher NIHSS (Hedge’s-G 0.96) and larger infarct volume (diffusion-weighted MRI, Hedge’s-G 0.8). In IV-tPA treated patients, PH correlated with antiplatelet (OR 3) and statin treatment (OR 4). HT (OR 3) and PH (OR 8) were associated with a poor outcome at 90-day (mRS 5–6). Hemorrhagic transformation is a frequent complication of acute ischemic stroke and is associated with poor outcome. Recognition of risk factors for HT and PH may reduce their incidence and severity.

Improving Cerebral Blood Flow after Arterial Recanalization: A Novel Therapeutic Strategy in Stroke

Ischemic stroke is caused by a disruption in blood supply to a region of the brain. It induces dysfunction of brain cells and networks, resulting in sudden neurological deficits. The cause of stroke is vascular, but the consequences are neurological. Decades of research have focused on finding new strategies to reduce the neural damage after cerebral ischemia. However, despite the incredibly huge investment, all strategies targeting neuroprotection have failed to demonstrate clinical efficacy. Today, treatment for stroke consists of dealing with the cause, attempting to remove the occluding blood clot and recanalize the vessel. However, clinical evidence suggests that the beneficial effect of post-stroke recanalization may be hampered by the occurrence of microvascular reperfusion failure. In short: recanalization is not synonymous with reperfusion. Today, clinicians are confronted with several challenges in acute stroke therapy, even after successful recanalization: (1) induce reperfusion, (2) avoid hemorrhagic transformation (HT), and (3) avoid early or late vascular reocclusion. All these parameters impact the restoration of cerebral blood flow after stroke. Recent advances in understanding the molecular consequences of recanalization and reperfusion may lead to innovative therapeutic strategies for improving reperfusion after stroke. In this review, we will highlight the importance of restoring normal cerebral blood flow after stroke and outline molecular mechanisms involved in blood flow regulation.

Hemorrhagic Transformations after Thrombectomy: Risk Factors and Clinical Relevance

BACKGROUND

Hemorrhagic transformation (HT) is a major complication of acute ischemic stroke, potentially associated with clinical deterioration. We attempted to identify risk factors and evaluated clinical relevance of minor and major HTs following endovascular thrombectomy (ET) in isolated middle cerebral artery (MCA) occlusions.

METHODS

This is a retrospective single-center analysis of 409 patients with isolated MCA occlusion treated with ET. Patients' and procedural characteristics, severity of HT according to the European Cooperative Acute Stroke Study criteria, and clinical outcomes were analyzed. Multivariate logistic regression models with standard retention criteria (p < 0.1) were used to determine risk factors and clinical relevance of HT. Results are shown as adjusted OR (aOR) and respective 95% CIs. Good neurologic short-term outcome was defined as National Institutes of Health Stroke Scale (NIHSS) score <5 at the day of discharge.

RESULTS

Of 299 patients included, hemorrhagic infarction (HI) was detected in 87 patients, while 13 patients developed parenchymal hematoma (PH). Higher age (aOR 0.970, 95% CI 0.947-0.993, p = 0.012), eligibility for intravenous recombinant tissue plasminogen activator (IV rtPA; aOR 0.512, 95% CI 0.267-0.982, p = 0.044), and complete recanalization (TICI 3, aOR 0.408, 95% CI 0.210-0.789, p = 0.008) were associated with a lower risk of HI. Risk factors for HI included higher admission NIHSS score (aOR 1.080, 95% CI 1.010-1.153, p = 0.024) and higher admission glucose levels (aOR 1.493, 95% CI 1.170-1.904, p = 0.001). Further, female sex tended to be associated with a lower risk of HI (aOR 0.601, 95% CI 0.316-1.143, p = 0.121), while a statistical trend was observable for proximal MCA occlusion (aOR 1.856, 95% CI 0.945-3.646, p = 0.073) and a history of hypertension (aOR 2.176, 95% CI 0.932-5.080, p = 0.072) to increase risk of HI. Longer intervals from symptom onset to first digital subtraction angiography runs (aOR 1.013, 95% CI 1.003-1.022, p = 0.009), lower preinterventional Alberta Stroke Program Early CT score (aOR 0.536, 95% CI 0.307-0.936, p = 0.028) and wake-up stroke (aOR 18.540, 95% CI 1.352-254.276, p = 0.029) were associated with PH. Both, PH and HI were independently associated with lower rates of good neurologic outcome (aOR 0.086, 95% CI 0.008-0.902, p = 0.041 and aOR 0.282, 95% CI 0.131-0.606, p = 0.001).

CONCLUSION

Risk of HI following MCA occlusion and subsequent ET is mainly determined by factors influencing infarct severity. Good recanalization results seem to be protective against subsequent HI. Our results support the notion that occurrence of PH after ET is time dependent and risk increases with more extensive early ischemic damage. Both, HI and PH do not seem to be facilitated by bridging therapy with IV rtPA or the use of oral anticoagulants, but were independently associated with more severe neurologic disability. These results support the notion that HI is not a "benign" imaging sign.