Rationale, Design, and Implementation of Intensive Risk Factor Treatment in the CREST2 Trial

Effect of Statin Therapy on Cardiovascular Outcome in Stroke Patients with Low Baseline Low-Density Lipoprotein Cholesterol

OBJECTIVES

To investigate whether post-stroke statin therapy reduces subsequent major vascular events in statin-naïve patients with pretreatment low-density lipoprotein cholesterol (LDL-C) below the recommended target (≤70 mg/dL for atherosclerotic stroke and ≤100 mg/dL for non-atherosclerotic stroke) at stroke onset.

METHODS

Patients from an ongoing stroke registry who had an ischemic stroke between 2011 and 2020 were screened. Statin naïve patients with baseline LDL-C below the target were assessed. The effect of post-stroke statin therapy on major vascular events (composite of recurrent stroke, myocardial infarction, and death) was investigated using weighted Cox regression analyses using stabilized inverse probability treatment weighting.

RESULTS

The baseline LDL-C level of the 1,858 patients (mean age 67.9 ± 15.3 years, 61.4% men, 13.2% atherosclerotic stroke) included in the study was 75.7 ± 17.0 mg/dL. Statins were prescribed to 1,256 (67.7%) patients (low-to-moderate intensity, 23.5%; high intensity, 44.1%). Post-stroke statin therapy was associated with a lower risk of major vascular events during 1-year follow-up (weighted hazard ratio 0.55, 95% confidence interval 0.42-0.71). In a subgroup of patients who were at very high risk of atherosclerotic cardiovascular disease with LDL-C <55 mg/dL or patients who were not at very high risk of atherosclerotic cardiovascular disease with LDL-C <70 mg/dL, post-stroke statin therapy was also associated with a reduction in major vascular events (weighted hazard ratio 0.45, 95% confidence interval 0.29-0.70). The intensity of the most beneficial statin varied by subtype of stroke.

INTERPRETATION

Statin therapy may improve vascular outcomes after ischemic stroke, even in cases of LDL-C below the target without pre-stroke lipid-lowering therapy. ANN NEUROL 2024;95:876-885.

Management of carotid atherosclerosis in stroke

Internal carotid artery atherosclerosis is a major risk factor for stroke, accounting for 15-20% of ischaemic strokes. Revascularisation procedures-either carotid endarterectomy or carotid artery stenting-can reduce the risk of stroke for those with significant (>50%) luminal stenosis but particularly for those with more severe (70-99%) stenosis. However, advances in medical pharmacotherapy have implications for the relative benefit from surgery for symptomatic carotid atherosclerosis, as well as our approach to asymptomatic disease. This review considers the evidence underpinning the current medical and surgical management of symptomatic carotid atherosclerosis, the importance of factors beyond the degree of luminal stenosis, and developments in therapeutic strategies. We also discuss the importance of non-stenotic but high-risk carotid atherosclerotic plaques on the cause of stroke, and their implications for clinical practice.

Evaluating the influence of altered cerebral hemodynamics on cognitive performance in asymptomatic carotid artery stenosis: A systematic review

OBJECTIVE

Substantial controversy exists regarding asymptomatic carotid stenosis (ACS) and its potential role in the pathophysiology of cognitive impairment. If proven, this hypothesis may suggest an additional definition for symptomatic carotid disease that would alter current management. This study aimed to synthesize the literature evaluating the relationship between impaired cerebral hemodynamics and cognition in patients with ACS.

METHODS

A literature search was performed using MEDLINE, Embase, and EBM Reviews through May 2022. We included prospective case-control studies that used validated, objective measure(s) of either global cognition or one or more domains of cognitive function and assessed cerebrovascular reserve (CVR).

RESULTS

Five studies were included, comprising a total of 782 patients with moderate (50%-69%) to severe (70%-99%) ACS. Patients with ACS and impaired ipsilateral CVR demonstrated significant cognitive impairment compared with controls. Patients with unilateral or bilateral ACS and normal CVR had cognitive scores similar to controls. Those with bilateral CVR impairment demonstrated the lowest cognitive scores.

CONCLUSIONS

This review lends support to the claim that cognitive impairment, likely the result of impaired cerebral hemodynamics, is an under-recognized morbidity in patients with ACS. CVR may serve as an additional tool to determine whether patients are in fact symptomatic from their carotid stenosis and warrant consideration for intervention.

Quantitative patient graph analysis for transient ischemic attack risk factor distribution based on electronic medical records

A transient ischemic attack (TIA) affects millions of people worldwide. Although TIA risk factors have been identified individually, a systemic quantitative analysis of all health factors relevant to TIA using electronic medical records (EMR) remains lacking. This study employed a data-driven approach, leveraging hospital EMR data to create a TIA patient health factor graph. This graph consisted of 737 TIA and 737 control patient nodes, 740 health factor nodes, and over 33,000 relations between patients and factors. For all health factors in the graph, the connection delta ratios (CDRs) were determined and ranked, generating a quantitative distribution of TIA health factors. A literature review confirmed 56 risk factors in the distribution and unveiled a potential new risk factor "rhinosinusitis" for future validation. Moreover, the patient graph was visualized together with the TIA knowledge graph in the Unified Medical Language System. This integration enables clinicians to access and visualize patient data and international standard knowledge within a unified graph. In conclusion, graph CDR analysis can effectively quantify the distribution of TIA risk factors. The resulting TIA risk factor distribution might be instrumental in developing new risk prediction machine learning models for screening and early detection of TIA.

Diagnosis and Management of Large Artery Atherosclerosis

OBJECTIVE

Ischemic stroke due to large vessel atherosclerosis is a significant cause of stroke globally. With the aging population, the number of people with atherosclerotic stroke will increase in the coming decades. This article reviews the recent developments in the assessment and treatment of extracranial and intracranial atherosclerotic disease.

LATEST DEVELOPMENTS

More intensive dual antiplatelet therapy can now be recommended for patients with transient ischemic attack or stroke. More stringent blood pressure and lipid control is also advised. The need for carotid revascularization will likely decrease in the coming decades because of advances in multimodal medical therapy; in particular, the role of revascularization for treating asymptomatic carotid stenosis is controversial. Patients with symptomatic intracranial stenosis should receive intensive medical therapy. Interest in high-resolution carotid plaque imaging is growing.

ESSENTIAL POINTS

The prevention of stroke due to large vessel atherosclerosis has improved owing to advances in medical therapies. The role of carotid revascularization is unclear for many patient subgroups.

Lessons From ACST-2

The recent 130-center, international, second ACST trial (Asymptomatic Carotid Surgery Trial) involving 3625 patients found that regardless of whether a patient underwent stenting or endarterectomy, the periprocedural risk of disabling or fatal stroke was about 1% and the 5-year estimated risk of nonprocedural disabling or fatal stroke was 2.5%. With advances in technique, technology, and patient selection, stenting done by appropriately trained and experienced operators can achieve safety and efficacy comparable to endarterectomy for asymptomatic patients. The ongoing CREST-2 trial (Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis Trial) will clarify whether revascularization, by either stenting or endarterectomy, remains an important therapeutic goal in the setting of modern intensive medical therapy.

Non-stenotic Carotid Plaques in Embolic Stroke of Unknown Source

Embolic stroke of unknown source (ESUS) represents one in five ischemic strokes. Ipsilateral non-stenotic carotid plaques are identified in 40% of all ESUS. In this narrative review, we summarize the evidence supporting the potential causal relationship between ESUS and non-stenotic carotid plaques; discuss the remaining challenges in establishing the causal link between non-stenotic plaques and ESUS and describe biomarkers of potential interest for future research. In support of the causal relationship between ESUS and non-stenotic carotid plaques, studies have shown that plaques with high-risk features are five times more prevalent in the ipsilateral vs. the contralateral carotid and there is a lower incidence of atrial fibrillation during follow-up in patients with ipsilateral non-stenotic carotid plaques. However, non-stenotic carotid plaques with or without high-risk features often coexist with other potential etiologies of stroke, notably atrial fibrillation (8.5%), intracranial atherosclerosis (8.4%), patent foramen ovale (5-9%), and atrial cardiopathy (2.4%). Such puzzling clinical associations make it challenging to confirm the causal link between non-stenotic plaques and ESUS. There are several ongoing studies exploring whether select protein and RNA biomarkers of plaque progression or vulnerability could facilitate the reclassification of some ESUS as large vessel strokes or help to optimize secondary prevention strategies.

Risk Factors Control and Early Recurrent Cerebral Infarction in Patients with Symptomatic Intracranial Atherosclerotic Disease

BACKGROUND

The risk of early recurrent cerebral infarction (RCI) is high in patients with symptomatic intracranial atherosclerotic disease (IAD). We sought to determine the relationship between risk factor control and early RCI risk among patients with symptomatic IAD.

METHODS

We analyzed participants with symptomatic IAD in the multi-center prospective observational MYRIAD study. Risk factor control was assessed at 6-8-week follow-up. Optimal risk factor control was defined by target systolic blood pressure, being non-smoker, target physical activity, and antiplatelet and antilipidemic therapy compliance. Age-adjusted associations were calculated between risk factor control and RCI determined by MRI-evident new infarcts in the territory of the stenotic vessel at 6-8 weeks from the index event.

RESULTS

Among 82 participants with clinical and brain MRI information available 6-8 weeks after the index event (mean age 63.5 ±12.5 years, 62.2% men), RCI occurred in 21 (25.6%) cases. At 6-8-week follow-up, 37.8% had target systolic blood pressure, 92.7% were non-smokers, 51.2% had target physical activity, and 98.8% and 86.6% were compliant with antiplatelet and antilipidemic therapy, respectively. Optimal risk factor control increased from 4.9% at baseline to 19.5% at 6-8-week follow-up (p=0.01). None of the participants with optimal risk factor control at follow-up had RCI (0% vs. 31.8%, p<0.01).

CONCLUSIONS

Only one-fifth of MYRIAD participants had optimal risk factor control during early follow-up. Approximately half and two-thirds had physical inactivity and uncontrolled systolic blood pressure, respectively. These risk factors may represent important therapeutic targets to prevent early RCI in patients with symptomatic IAD.

Optimal Medical Management of Asymptomatic Carotid Stenosis

Asymptomatic carotid stenosis (ACS) due to atherosclerosis is a risk factor for ipsilateral ischemic cerebrovascular events and cognitive impairment. The prognosis of ACS has improved over the past 4 decades due largely to improvements in medical management. Most patients with ACS can be managed without revascularization, but some patients with vulnerable plaque should be considered for revascularization. Regardless of the decision to refer for revascularization, all patients with ACS should receive intensive medical management. This includes lifestyle modification (Mediterranean diet, exercise, and smoking cessation) and pharmacological therapy (antiplatelets, lipid-lowering agents, blood pressure reduction, and glycemic control). Patients with ACS often have atherosclerosis in other critical locations, and thus optimal medical therapy is likely to reduce events outside the carotid arteries. The nature of optimal medical therapy is described.