PCSK9 Inhibitor with Statin Therapy for Intracranial Artery Stenosis ( PISTIAS): Rationale and design of a multicenter randomized controlled trial.

RATIONALE: Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors enable an additional 54-75% reduction in low-density lipoprotein cholesterol (LDL-C) in statin-treated patients, demonstrating plaque regression in coronary artery disease. However, the impact of achieving an extremely low level of LDL-C with PCSK9 inhibitors (e.g. Evolocumab) on symptomatic intracranial atherosclerosis remains unexplored. AIM AND HYPOTHESIS: To determine whether combining Evolocumab and statins achieves a more significant symptomatic intracranial plaque regression than statin therapy alone. SAMPLE SIZE ESTIMATES: With a sample size of 1000 subjects, a two-sided α of 0.05, and 20% lost to follow-up, the study will have 83.3% power to detect the difference in intracranial plaque burden. METHODS AND DESIGN: This is an investigator-initiated multicenter, randomized, open-label, outcome assessor-blinded trial, evaluating the impact of combining Evolocumab and statins on intracranial plaque burden assessed by high-resolution magnetic resonance imaging at baseline in patients undergoing a clinically indicated acute stroke or transient ischemic attack due to intracranial artery stenosis, and after 24 weeks of treatment. Subjects (n = 1000) were randomized 1:1 into two groups to receive either Evolocumab 140 mg every 2 weeks with statin therapy or statin therapy alone. STUDY OUTCOMES: The primary endpoint is the change in intracranial plaque burden assessed by high-resolution magnetic resonance imaging, performed at baseline and at the end of the 24-week treatment period. DISCUSSION: This trial will explore whether more significant intracranial plaque regression is achievable with the treatment of combining Evolocumab and statins, providing information about efficacy and safety data. TRIAL REGISTRATION NUMBER: ChiCTR2300068868; https://www.chictr.org.cn/.

Vascular Endothelial Growth Factor and Ischemic Stroke Risk: A Mendelian Randomization Study.

INTRODUCTION: Previous studies have reported controversial relationships between circulating vascular endothelial growth factors (VEGF) and ischemic stroke (IS). This study aims to demonstrate the causal effect between VEGF and IS using Mendelian randomization (MR). METHODS: Summary statistics data from two large-scale genome-wide association studies (GWAS) for 16,112 patients with measured VEGF levels and 40,585 patients with IS were downloaded from public databases and included in this study. A published calculator was adopted for MR power calculation. The primary outcome was any ischemic stroke, and the secondary outcomes were large-artery stroke, cardioembolic stroke, and small-vessel stroke. We used the inverse variance-weighted (IVW) method for primary analysis, supplemented by MR-Egger regression and the weighted median method. RESULTS: Nine SNPs were included to represent serum VEGF levels. The IVW method revealed no strong causal association between VEGF and any ischemic stroke (odds ratio [OR] 1.01, 95% CI 0.99-1.04, p = 0.39), cardioembolic stroke (OR 1.04, 95% CI 0.97-1.12, p = 0.28), large-artery stroke (OR 1.02, 95% CI 0.95-1.09, p = 0.62), and small-vessel stroke (OR 0.98, 95% CI 0.91-1.04, p = 0.46). These findings remained robust in sensitivity analyses. MR-Egger regression suggested no horizontal pleiotropy. CONCLUSIONS: This Mendelian randomization study found no relationship between genetically predisposed serum VEGF levels and risks of IS or its subtypes.

Visceral Adiposity and Risk of Stroke: A Mendelian Randomization Study.

Purpose: In recent years, metabolic syndrome has risen in prevalence and brought a heavy disease burden to modern society. As the representative aspect of metabolic syndrome, obesity has been shown to be related to an increased risk of stroke. Given that visceral adipose tissue (VAT) forms the fundamental basis of central obesity, we sought to explore a causal relationship between VAT and stroke by using mendelian randomization (MR) methods. Methods: Based on two large genome-wide association studies (GWAS) including 325,153 and 35,762 cases of VAT and stroke, respectively, we conducted a MR study which has the inherent advantage of reducing the noise of confounding and reverse causation. Results: VAT had a significant causal association with ischemic stroke (OR, per 1kg increase in VAT mass, 1.30; 95% CI, 1.18 ~ 1.45; P = 5.87E-07) as opposed to intracranial hemorrhage (ICH) (OR, 1.15; 95% CI, 0.70 ~ 1.88, P = 5.81E-01) as evaluated with inverse-variance weighting (IVW). Regarding subtypes of ischemic stroke, there was a significant causal effect for cardioembolic stroke (OR, 1.34; 95% CI, 1.13 ~ 1.58, P = 8.07E-04), and potential causal effect for small-vessel stroke (OR, 1.32; 95% CI, 1.06 ~ 1.65, P = 1.39E-02) and large-artery atherosclerotic stroke (OR, 1.33; 95% CI, 1.03 ~ 1.70, P = 2.59E-02). Conclusions: This study provides potential evidence for a causal role of VAT in ischemic stroke and could suggest novel genetical therapeutic strategies for distinct subtypes of ischemic stroke.

Parkinson's Disease and Ischemic Stroke: a Bidirectional Mendelian Randomization Study.

We aimed to assess the potential causal association between Parkinson's disease (PD) and ischemic stroke (IS) with Mendelian randomization methods. Summary statistics data from two large-scale genome-wide association studies (GWAS) for 33,674 PD cases and 40,585 IS cases were used in this study. We used inverse variance-weighted method for primary analysis, and four other Mendelian randomization methods (weighted median, MR-Egger regression methods, robust adjusted profile score, radial regression) to test whether PD was causal for IS and its subtypes. Analyses were bidirectional to assess reverse causality. Primary analysis showed PD had a significantly causal association with IS (OR 1.04; 95% CI, 1.02-1.07; p = 0.0019), and two subtypes of IS, cardioembolic stroke (OR 1.11; 95% CI, 1.06-1.18; p = 0.0001) and large artery stroke (OR 1.08; 95% CI, 1.01-1.15; p = 0.034), but not with small-vessel stroke (p = 0.180). The point estimates from sensitivity analyses were in the same direction. There was no strong evidence for a reverse causal association between PD and IS. Using multiple Mendelian randomization methods based on large-scale GWAS, PD is a potential cause of cardioembolic stroke and large artery stroke, but not small-vessel stroke. Ischemic stroke does not cause PD.