Recurrence risk in symptomatic intracranial stenosis treated medically in the real world

Stroke risk prediction in symptomatic anterior circulation ICAD: Analysis of regional QMRA flow from the MYRIAD study

BACKGROUND

Intracranial atherosclerotic disease (ICAD) remains a major source of stroke world-wide, with high recurrence risk. Prior evaluation of posterior circulation ICAD patients enrolled in the prospective VERiTAS and MYRIAD studies revealed regional hypoperfusion assessed by large vessel flow measurements using quantitative MRA (QMRA) predicts subsequent stroke risk. We examined whether a similar approach to regional flow assessment predicted stroke risk in anterior circulation ICAD patients in MYRIAD.

METHODS

MYRIAD enrolled patients with symptomatic 50-99 % stenosis of proximal intracranial artery. The primary outcome was recurrent ischemic stroke in the stenotic artery territory within one year. Flow was measured in the major intracranial arteries at baseline using QMRA. We designated patients as low or normal flow based on an algorithm assessing distal flow and collateral capacity using age-normalized middle cerebral artery (MCA) and hemispheric flows. Thresholds for flow status categorization were tested to determine the optimal algorithm for stroke risk prediction.

RESULTS

Of 73 enrolled subjects with symptomatic anterior circulation ICAD, 7 (9.6 %) had recurrent stroke. Z-score thresholds for age-normalized flow were examined, from which we identified an optimal threshold of -1 for the MCA and -0.75 for hemispheric flow. Based on these thresholds, 24 (33 %) patients were categorized as low flow; recurrent stroke occurred in 21 % of low flow vs 4 % of normal flow patients (age adjusted OR 7.2, 95 % CI 1.2-43.2). In the full cohort of 99 subjects with anterior and posterior circulation ICAD, 11 (11.1 %) had recurrent stroke, with a higher recurrent stroke risk in low flow patients (21.4 % vs 7 %, age adjusted OR 3.8, 95 % CI 1.02-14.2).

CONCLUSIONS

Distal flow status assessed through QMRA regional flow measurement appears to be similarly predictive for recurrent clinical stroke in both the anterior and posterior ciruclation. Identification of high-risk patients has implications for future investigation of therapeutic interventions.

Endovascular therapy versus best medical treatment for symptomatic intracranial atherosclerotic stenosis: A systematic review and meta-analysis

INTRODUCTION

Evidence on endovascular therapy (EVT) for symptomatic intracranial stenosis (sICAS) from randomized-controlled clinical trials (RCTs) is conflicting. While prior RCTs on percutaneous transluminal angioplasty and stenting (PTAS) demonstrated harm or no benefit over best medical treatment (BMT), recent data suggest that submaximal balloon angioplasty with BMT may be superior to BMT alone.

PATIENTS AND METHODS

A systematic review and meta-analysis of RCTs was conducted to evaluate the safety and efficacy of elective EVT plus BMT compared to BMT alone for sICAS.

RESULTS

Six RCTs (5 on PTAS and 1 on balloon-angioplasty) comprising 1606 patients were included. EVT increased the risk of any stroke or death (RR = 2.68; 95% CI: 1.72-4.19; I2 = 0%), ischemic stroke within the territory of the qualifying artery (RR = 2.51; 95% CI: 1.36-4.61; I2 = 0%), any ischemic stroke (RR = 1.99; 95% CI: 1.17-3.38; I2 = 0%), intracranial hemorrhage (RR = 6.23; 95% CI: 1.92-20.2; I2 = 0%), and mortality (RR = 3.52; 95% CI: 1.04-11.88; I2 = 0%) within 30 days. No significant benefit from EVT was detected regarding the risk of any stroke or death (RR = 0.29, 95% CI: 0.06-1.38; I2 = 68%), ischemic stroke in the territory of the qualifying artery (RR = 0.44, 95% CI: 0.14-1.33; I2 = 59%) and mortality (RR = 0.49, 95% CI: 0.16-1.55; I2 = 0%) beyond 30 days through 1 year.

DISCUSSION AND CONCLUSION

EVT is associated with adverse early outcomes, without reducing the risk of long-term stroke recurrence or mortality compared to BMT. Further research is warranted to identify high-risk subgroups who may benefit from EVT for sICAS and refine interventions to minimize periprocedural risks.

PCSK9 inhibitors reduced early recurrent stroke in patients with symptomatic intracranial atherosclerotic stenosis

BACKGROUND

Symptomatic intracranial atherosclerotic stenosis (ICAS) is prone to cause early recurrent stroke (ERS). Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors lower low-density lipoprotein cholesterol (LDL-C) levels and prevent cardiovascular events. This multicentre, hospital-based prospective cohort study was designed to investigate whether PCSK9 inhibitors would prevent ERS in patients with symptomatic ICAS.

METHODS

From 1 October 2020 to 30 September 2022, consecutive patients with acute ischaemic stroke attributed to ICAS admitted within 1 week after onset were enrolled and followed up for 1 month. Patients were divided into two groups, the PCSK9 inhibitors group receiving PCSK9 inhibitors add-on therapy, and the control group receiving statins and/or ezetimibe. The primary outcome was ERS. Cox proportional hazard models and Kaplan-Meier survival curve were used to estimate the association between PCSK9 inhibitors and ERS.

RESULTS

At the end of follow-up, the LDL-C levels were further lowered by PCSK9 inhibitors add-on therapy (n=232, from 3.06±1.16 mmol/L to 2.12±1.19 mmol/L) than statins and/or ezetimibe treatment (n=429, from 2.91±1.05 mmol/L to 2.64±0.86 mmol/L, p<0.001). The Kaplan-Meier survival curves showed that PCSK9 inhibitors add-on therapy significantly reduced ERS (5.59%, 24/429, vs 2.16%, 5/232; log-rank test, p=0.044). The multivariate Cox regression analysis revealed that, after adjusting for confounders with a p value less than 0.05 in univariate analysis or of particular importance, the HR was 0.335 (95% CI 0.114 to 0.986, p=0.047), compared with the control group.

CONCLUSIONS

In our study, PCSK9 inhibitors add-on therapy further reduced LDL-C levels and ERS in patients with symptomatic ICAS.

Emergent Large Vessel Occlusion due to Intracranial Stenosis: Identification, Management, Challenges, and Future Directions

This comprehensive literature review focuses on acute stroke related to intracranial atherosclerotic stenosis (ICAS), with an emphasis on ICAS-large vessel occlusion. ICAS is the leading cause of stroke globally, with high recurrence risk, especially in Asian, Black, and Hispanic populations. Various risk factors, including hypertension, diabetes, hyperlipidemia, smoking, and advanced age lead to ICAS, which in turn results in stroke through different mechanisms. Recurrent stroke risk in patients with ICAS with hemodynamic failure is particularly high, even with aggressive medical management. Developments in advanced imaging have improved our understanding of ICAS and ability to identify high-risk patients who could benefit from intervention. Herein, we focus on current management strategies for ICAS-large vessel occlusion discussed, including the use of perfusion imaging, endovascular therapy, and stenting. In addition, we focus on strategies that aim at identifying subjects at higher risk for early recurrent risk who could benefit from early endovascular intervention The review underscores the need for further research to optimize ICAS-large vessel occlusion treatment strategies, a traditionally understudied topic.