The role of statins in cardioembolic stroke

Statin treatment in stroke patient with low-density lipoprotein cholesterol levels below 70 mg/dL

BACKGROUND AND PURPOSE

The effectiveness of hyperlipidemia treatment in strokes secondary prevention has been established. However, whether pretreatment with statins could confer protective effects when a patient's baseline low-density lipoprotein cholesterol (LDL-C) level is <70 mg/dL remains uncertain. Additionally, the ability of statin treatment to reduce poststroke complications, mortality, and recurrence in this patient group is unclear.

METHODS AND RESULTS

In this retrospective observational study, we enrolled patients who had experienced an ischemic stroke with LDL-C levels <70 mg/dL. We analyzed the association of statin use with baseline characteristics, stroke severity, in-hospital complications, mortality rates, stroke recurrence rate, and mortality rate. Patients who used and patients who did not use statins were similar in terms of age and sex. Patients using statins had higher rates of diabetes mellitus, hypertension, prior stroke, and coronary artery disease but a lower incidence of atrial fibrillation. Stroke severity was less pronounced in those using statins. We also evaluated the relationship between in-hospital statin use and complications. We noted that in-hospital statin use was associated with lower rates of infection, hemorrhagic transformation, gastrointestinal hemorrhage, and mortality, as well as higher rates of positive functional outcomes. The 1-year recurrence rate was similar in both groups.

CONCLUSIONS

Statin use is associated with milder strokes and improved poststroke outcomes, even in patients with well-controlled LDL levels. Neurologists may consider prescribing statins for patients with ischemic stroke who do not overt hyperlipidemia. Further research into potential underlying mechanisms is warranted.

Effectiveness of statins on outcomes of patients with Embolic Stroke of Undetermined Source (ESUS)

BACKGROUND

Statins are highly recommended as a secondary prevention strategy after a stroke. Embolic Stroke of Undetermined Source (ESUS) accounts for up to one fifth of cases of ischemic stroke. There is a lack of studies investigating the effectiveness of statins in this subgroup of patients.

METHODS

We designed a longitudinal cohort study involving patients properly diagnosed with ESUS. Data about statin therapy included information about the time of initiation of the treatment, pre-stroke statin use, statin withdrawal, and the type and dosage of the statin prescribed. Patients were followed for 48 months after the index stroke. The primary endpoints included stroke recurrence, major cardiovascular events, and death from all causes. The secondary endpoint was the functional outcome, assessed in a standardized and systematic way using the modified Rankin Scale (mRS).

RESULTS

Patients who were not taking any statin after ESUS have significantly increased odds of stroke recurrence (OR = 3.29, 95% CI 1.27 - 8.55) or presenting the composite outcome of stroke recurrence, major cardiovascular events, and death (OR = 3.70, 95% CI 1.44 - 9.50) in the multivariate analysis. No statin therapy was directly associated with the functional outcome as well (OR = 3.32, 95% CI = 1.58 - 6.96). The early initiation of the statin therapy was estimated to reduce the risk of a second stroke and the composite outcome by 89% and 87%.

CONCLUSIONS

Our pioneering study provides evidence that patients with ESUS may benefit from statin therapy, especially if prescribed early and at higher dosages.

Evolving Clinical-Translational Investigations of Cerebroprotection in Ischemic Stroke

Ischemic stroke is a highly morbid disease, with over 50% of large vessel stroke (middle cerebral artery or internal carotid artery terminus occlusion) patients suffering disability despite maximal acute reperfusion therapy with thrombolysis and thrombectomy. The discovery of the ischemic penumbra in the 1980s laid the foundation for a salvageable territory in ischemic stroke. Since then, the concept of neuroprotection has been a focus of post-stroke care to (1) minimize the conversion from penumbra to core irreversible infarct, (2) limit secondary damage from ischemia-reperfusion injury, inflammation, and excitotoxicity and (3) to encourage tissue repair. However, despite multiple studies, the preclinical-clinical research enterprise has not yet created an agent that mitigates post-stroke outcomes beyond thrombolysis and mechanical clot retrieval. These translational gaps have not deterred the scientific community as agents are under continuous investigation. The NIH has recently promoted the concept of cerebroprotection to consider the whole brain post-stroke rather than just the neurons. This review will briefly outline the translational science of past, current, and emerging breakthroughs in cerebroprotection and use of these foundational ideas to develop a novel paradigm for optimizing stroke outcomes.

The Effect of Simvastatin on the Dynamics of NF-κB-Regulated Neurodegenerative and Neuroprotective Processes in the Acute Phase of Ischemic Stroke

Statins are lipid-lowering drugs that act by inhibiting 3-hydroxy-3-methylglutaryl coenzyme A reductase, a rate-limiting enzyme in cholesterol biosynthesis. Animal studies have shown neuroprotective effects of statins in cerebral stroke. However, the underlying mechanisms are not fully understood. The nuclear factor-kappa B (NF-κB) transcription factor is involved in the regulation of apoptosis in stroke. Different dimers of NF-κB regulate the gene expression of proteins involved in both neurodegeneration and neuroprotection. We aimed to determine whether simvastatin improves stroke outcome via inhibition of the RelA/p65-containing subunit and downregulation of stroke-induced pro-apoptotic genes or via activation of NF-κB dimers containing the c-Rel subunit and upregulation of anti-apoptotic genes during the acute stroke phase. Eighteen-month-old Wistar rats, subjected to permanent MCAO or sham surgery, were administered simvastatin (20 mg/kg b.w.) or saline for 5 days before the procedure. Stroke outcome was determined by measuring cerebral infarct and assessing motor functions. The expression of NF-κB subunits in various cell populations was investigated using immunofluorescence/confocal microscopy. RelA and c-Rel were detected by WB. The NF-κB-DNA binding activity was investigated using EMSA, and expression of Noxa, Puma, Bcl-2, and Bcl-x genes was analyzed by qRT-PCR. Results showed a 50% infarct size reduction and significant motor function improvement in the simvastatin-treated animals which correlated with a decrease in RelA and a transient increase in the c-Rel level in the nucleus, normalization of the NF-κB-DNA binding activity, and downregulation of the NF-κB-regulated genes. Our results provide new insights into the statin-mediated neuroprotective action against stroke based on NF-κB pathway inhibition.

The prognostic significance of the lipid profile after an ischemic stroke

BACKGROUND

The role that cholesterol levels play in stroke is still uncertain, especially in secondary prevention. The aim was to determine how a comprehensive analysis of the lipid profile can be associated with post-stroke outcomes.

Consecutive patients diagnosed with ischemic stroke were included in our cohort and followed up for 24months. Baseline clinical and demographic data were collected as well as a complete lipid profile 6-months after the index stroke. Lipid variables were analyzed quantitatively and qualitatively. Clinical outcomes included stroke recurrence, major cardiovascular events, and functional performance (assessed with the modified Rankin scale).

RESULTS

The study included 588 patients with an average age of 58.3 years. There were 148 (25.2%) patients with high total cholesterol, 260 (44.2%) with low HDL, 180 (30.6%) with high LDL, and 204 (34.7%) with high triglycerides. There were 164 (27.9%) patients with no abnormalities in the lipid profile. After the follow-up, 108 (18.3%) had another stroke, 32 (5.4%) had major cardiovascular events, and 360 (61.2%) presented good functional outcomes. A higher LDL-C/HDL-C ratio and a low HDL-C level were significantly associated with worse cardiovascular outcomes. The detection of LDL-C > 70 mg/dL was an independent predictor of a higher risk of stroke recurrence and worse functional performance. The greater the number of altered lipid variables, the greater the chance of developing an unfavorable composite outcome and presenting cardiovascular events after the stroke.

CONCLUSIONS

The complete analysis of the lipid panel allows the determination of the prognosis of patients who suffered a stroke.

The Effect of Statin Treatment on Outcomes of Cardioembolic Stroke: A Systematic Review and Meta-Analysis of Real-World Studies

BACKGROUND

Several real-world observational studies have investigated the association between statin treatment and outcomes of cardioembolic stroke. However, substantial uncertainties remain about this association.

OBJECTIVE

We aimed to perform a systematic review and meta-analysis to determine the effect of statin treatment on the outcomes of cardioembolic stroke.

METHODS

We systematically searched the PubMed and Embase databases for relevant clinical studies. Pooled relative risks (RRs) and 95% confidence intervals (CIs) with a random-effects model were used to assess the outcomes of interest.

RESULTS

A total of 18 observational studies published between 2009 and 2020 were included. No randomized clinical trial was found. Compared with non-statin treatment, statin treatment was not associated with a decreased risk of stroke recurrence in patients with cardioembolic stroke [PWCS] (RR, 0.93; 95% CI 0.82-1.06). However, compared with non-statin treatment, statin treatment was associated with a lower risk of all-cause death (RR, 0.59; 95% CI 0.49-0.73) and better functional outcomes (RR, 0.67; 95% CI 0.47-0.97) in PWCS. There was no significant association between statin treatment and major bleeding event risk in PWCS (RR, 0.35; 95% CI 0.06-2.16). Compared with non-statin treatment, statin treatment was not associated with a decreased risk of coronary atherosclerotic disease in PWCS (RR, 1.04; 95% CI 0.96-1.11).

CONCLUSIONS

Although the use of statins does not enhance the prevention of stroke recurrence in PWCS, statin treatment is associated with improved clinical outcomes in PWCS. Statins play a beneficial role in the treatment of cardioembolic stroke.

Role of Blood Lipid Levels and Lipid-Lowering Therapy in Stroke Patients with Different Levels of Cerebral Artery Diseases: Reconsidering Recent Stroke Guidelines

Hyperlipidemia is an important risk factor for ischemic stroke; the Stroke Prevention by Aggressive Reduction in Cholesterol Level and Treat Stroke to Target studies have shown that statins are beneficial for patients with stroke and that a low target for low-density lipoprotein cholesterol (LDL-C) concentration may maximize this benefit. Based on these results, recent guidelines have emphasized the application of "high-intensity statins" and "low LDL-C target" strategies in patients with stroke. However, it should be kept in mind that the role of blood lipids as a risk factor and benefit of lipid-lowering therapy are different among patients with different levels of cerebral arterial diseases. Studies have suggested that hypolipidemia, but not hyperlipidemia, is a risk factor for small vessel diseases (SVDs) such as intracerebral hemorrhages, microbleeds, white matter hyperintensities, and perhaps, lacunar infarction. Although lipid-lowering agents might benefit certain patients with SVD, high-intensity statin and low LDL-C target strategies cannot be applied. In contrast, these strategies are important in patients with extracranial atherosclerosis, such as internal carotid disease, considering ample evidence of the benefits of lipid-lowering agents. Imaging studies have shown that statins stabilize vulnerable plaques in these patients. Although lipid-lowering agents are likely to benefit patients with intracranial atherosclerosis, the degree of their benefit and appropriate target LDL-C level for these patients remain unclear. More studies are needed to elucidate the appropriate lipid-modifying strategies in patients with stroke with different levels of cerebral artery disease.

LDL-C/HDL-C is associated with ischaemic stroke in patients with non-valvular atrial fibrillation: a case-control study

BACKGROUND

This study explored the relationships between the low-/high-density lipoprotein cholesterol ratio (LDL-C/HDL-C) and other clinical indicators and ischaemic stroke (IS) in patients with non-valvular atrial fibrillation (NVAF) in Xinjiang. The findings could provide a theoretical and therapeutic basis for NVAF patients.

METHODS

NVAF patients who were admitted to 10 medical centres across Xinjiang were divided into stroke (798 patients) and control (2671 patients) groups according to the occurrence of first acute IS. Univariate and multivariate logistic regression analysis were used to examine the independent risk factors for IS in NVAF patients. Factor analysis and principal component regression analysis were used to analyse the main factors influencing IS. Receiver operating characteristic (ROC) curve analysis was used to evaluate the discriminatory ability of LDL-C/HDL-C for predicting the occurrence of IS.

RESULTS

The stroke group had an average age of 71.64 ± 9.96 years and included 305 females (38.22%). The control group had a mean age of 67.30 ± 12.01 years and included 825 females (30.89%). Multivariate logistic regression showed that the risk of IS in the highest LDL-C/HDL-C quartile (≥2.73) was 16.23-fold that of the lowest quartile (< 1.22); IS risk was 2.27-fold higher in obese patients than in normal-weight subjects; IS risk was 3.15-fold higher in smoking patients than in non-smoking patients. The area under the ROC curve of LDL-C/HDL-C was 0.76, the optimal critical value was 2.33, the sensitivity was 63.53%, and the specificity was 76.34%. Principal component regression analysis showed that LDL-C/HDL-C, age, smoking, drinking, LDL-C and hypertension were risk factors for IS in NVAF patients.

CONCLUSIONS

LDL-C/HDL-C > 1.22, smoking, BMI ≥24 kg/m² and CHA₂DS₂-VASc score were independent risk factors for IS in NVAF patients; LDL-C/HDL-C was the main risk factor.

Use of statins for the secondary prevention of stroke: are we respecting the scientific evidences?

BACKGROUND

Stroke accounts for approximately as 5.0% of disability-adjusted years of life and 10.0% of all deaths worldwide. Secondary stroke prevention in surviving individuals, which includes the use of statins, reduces atherothrombotic stroke recurrence, complications and mortality. The present study aimed to characterize the Brazilian population with stroke history and estimate the prevalence of statin use as secondary prevention.

METHODS

This is a population-based cross-sectional study conducted in Brazilian urban areas. A total of 41.433 individuals were interviewed, representing 171 million of Brazilians, based on post-stratification weights. We included only participants aged 20 years or older who answered "yes" to the following question: "Did any doctor ever tell you that you had a stroke?" The main outcome was the prevalence of statin use among individuals who answered affirmatively. To identify the factors associated with stroke occurrence, the participants were categorized according to clinical and sociodemographic characteristics.

RESULTS

Only 24.2% (95% CI 19.9 - 29.1) of those who reported history of stroke regardless of other conditions also reported statin use. However, the results indicated that 52.9% (95% CI 43.6 - 62.0) of individuals who reported a previous diagnosis of dyslipidemia stated the use of statins. Regarding patients who reported stroke and did not report dyslipidemia history, only 9.1% (95% CI 5.9 - 13.8) referred to use statins.

CONCLUSION

This study showed a low prevalence of statin use by individuals with a history of stroke in Brazil. Actions involving the organization of services and training of professionals may positively impact the rates of stroke recurrence.

Evaluating the utility of fasting lipid panel in addition to random lipid panel in determining lipid-lowering therapy in acute ischemic stroke or TIA patients

BACKGROUND

Hyperlipidemia is one of the major risk factors for cerebrovascular disease and it is common practice to obtain fasting lipid profile prior to starting lipid lowering therapy (LLT). Recent AHA Guidelines published in 2018 allow for a non-fasting value to be used.

OBJECTIVE

To determine if obtaining fasting lipid levels in addition to random lipid levels prompts changes in hyperlipidemia management of acute stroke patients.

METHODS

206 patients met the study criteria which included a diagnosis of acute ischemic stroke or transient ischemic attack on admission and availability of both random and fasting LDL levels collected within 72 h of each other. Patients were divided into three groups based on random LDL at admission: Group A: LDL < 70, Group B: LDL 70-99, and Group C: LDL ≥ 100 mg/dL. The dataset was analyzed to conform to the 2018 AHA/ACC guidelines using an LDL cutoff of 70 mg/dL.

RESULTS

In 206 patients, statin management would change based on the fasting LDL level in 12 patients, 11 of whom were in Group B. Our data suggests that lipid management is more likely to change if the initial random LDL falls between 70-99 mg/dL as compared to a value outside of this range (P < 0.001). We present a decision algorithm to guide lipid management in acute stroke patients.

CONCLUSIONS

Foregoing a fasting lipid panel to guide LLT in patients with ischemic stroke is appropriate in most cases but for select patients with random LDL levels between 70 and 99, fasting lipid profile should be obtained prior to deciding upon LLT.

Effects of statin therapy on outcomes of ischemic stroke: a real-world experience in Brazil

BACKGROUND

Statin therapy has become one of the most important advances in stroke secondary prevention.

OBJECTIVE

To provide evidence from real-world data for evaluating detailed associations between secondary prevention of stroke and statin use in Brazil.

METHODS

We conducted a prospective cohort study including consecutive patients diagnosed with an ischemic stroke. Subjects were classified into non-statin, simvastatin 20 mg, simvastatin 40 mg, and high-potency statin groups. We also registered the onset of statin therapy, previous use of statins, the adherence to medication, and if there was discontinuation of the therapy. After two years, the functional outcome, stroke recurrence, major cardiovascular events, and mortality were assessed.

RESULTS

Among the 513 patients included in our cohort, there were 96 (18.7%) patients without statins, 169 (32.9%) with simvastatin 20 mg, 202 (39.3%) with simvastatin 40 mg, and 46 (9.0%) with high-potency statins. Patients without statins were at increased risk of stroke recurrence and worse functional outcomes. Concerning etiology, evidence of beneficial use of statins was observed in cases of large-artery atherosclerosis, small-vessel occlusion, and stroke of undetermined cause. Those who presented poor adherence to statins or discontinuation of the treatment had worse prognosis after stroke whereas the early onset of statins use was associated with better outcomes. Patients with simvastatin 40 mg and high-potency statins presented the best functional recovery throughout the follow-up.

CONCLUSIONS

Statins play an important role in the treatment of ischemic stroke, preventing stroke recurrence and cardiovascular events, and improving functional performance.

The influence of statins on the risk of post-stroke epilepsy

BACKGROUND

Currently, statins are widely used for secondary prevention of stroke due to their pleiotropic neuroprotective effects. Epilepsy is a common complication of cerebrovascular diseases. The purpose of this study was to evaluate the effect of statin therapy on the occurrence of post-stroke epilepsy (PSE).

METHODS

In this prospective cohort study, patients who suffered an ischemic stroke and without history of epilepsy before stroke were enrolled. At baseline, patients were classified according to the particularities of statin therapy. Statin use onset and adherence to treatment were registered as well. After a follow-up period of 1 year, we assessed the occurrence of seizures and PSE.

RESULTS

Among the 477 patients included in our cohort, there were 91 (19.1%) patients without statins, 160 (33.5%) with simvastatin 20 mg, 180 (37.7%) with simvastatin 40 mg, and 46 (9.6%) with high-potency statins. Overall, PSE emerged in 53 (11.1%) patients. PSE was significantly more prevalent among those who did not receive statins and those with lower doses of simvastatin. Acute onset of statin use was associated with reduced odds of having PSE.

CONCLUSION

Adequate treatment with statins after stroke may lower the risk of PSE.