Aspirin treatment prevents inflammation in experimental bifurcation aneurysms in New Zealand White rabbits

Aspirin treatment for unruptured intracranial aneurysms: Focusing on its anti-inflammatory role

Intracranial aneurysms (IAs), as a common cerebrovascular disease, claims a worldwide morbidity rate of 3.2%. Inflammation, pivotal in the pathogenesis of IAs, influences their formation, growth, and rupture. This review investigates aspirin's modulation of inflammatory pathways within this context. With IAs carrying significant morbidity and mortality upon IAs rupture and current interventions limited to surgical clipping and endovascular coiling, the quest for pharmacological options is imperative. Aspirin's role in cardiovascular prevention, due to its anti-inflammatory effects, presents a potential therapeutic avenue for IAs. In this review, we examine aspirin's efficacy in experimental models and clinical settings, highlighting its impact on the progression and rupture risks of unruptured IAs. The underlying mechanisms of aspirin's impact on IAs are explored, with its ability examined to attenuate endothelial dysfunction and vascular injury. This review may provide a theoretical basis for the use of aspirin, suggesting a promising strategy for IAs management. However, the optimal dosing, safety, and long-term efficacy remain to be established. The implications of aspirin therapy are significant in light of current surgical and endovascular treatments. Further research is encouraged to refine aspirin's clinical application in the management of unruptured IAs, with the ultimate aim of reducing the incidence of aneurysms rupture.

Clopidogrel Is Associated with Reduced Likelihood of Aneurysmal Subarachnoid Hemorrhage: a Multi-Center Matched Retrospective Analysis

Maladaptive inflammation underlies the formation and rupture of human intracranial aneurysms. There is a growing body of evidence that anti-inflammatory pharmaceuticals may beneficially modulate this process. Clopidogrel (Plavix) is a commonly used irreversible P2Y12 receptor antagonist with anti-inflammatory activity. In this paper, we investigate whether clopidogrel is associated with the likelihood of aneurysm rupture in a multi-institutional propensity-matched cohort analysis. Patients presenting for endovascular treatment of their unruptured intracranial aneurysms and those presenting with aneurysm rupture between 2015 and 2019 were prospectively identified at two quaternary referral centers. Patient demographics, comorbidities, and medication usage at the time of presentation were collected. Patients taking clopidogrel or not taking clopidogrel were matched in a 1:1 fashion with respect to location, age, smoking status, aneurysm size, aspirin usage, and hypertension. A total of 1048 patients with electively treated aneurysms or subarachnoid hemorrhages were prospectively identified. Nine hundred twenty-one patients were confirmed to harbor aneurysms during catheter-based diagnostic angiography. A total of 172/921 (19%) patients were actively taking clopidogrel at the time of presentation. Three hundred thirty-two patients were matched in a 1:1 fashion. A smaller proportion of patients taking clopidogrel at presentation had ruptured aneurysms than those who were not taking clopidogrel (6.6% vs 23.5%, p < .0001). Estimated treatment effect analysis demonstrated that clopidogrel usage decreased aneurysm rupture risk by 15%. We present, to the best of our knowledge, the first large-scale multi-institutional analysis suggesting clopidogrel use is protective against intracranial aneurysm rupture. It is our hope that these data will guide future investigation, revealing the pathophysiologic underpinning of this association.

Imaging of intracranial aneurysms in animals: a systematic review of modalities

Intracranial aneurysm (IA) animal models are paramount to study IA pathophysiology and to test new endovascular treatments. A number of in vivo imaging modalities are available to characterize IAs at different stages of development in these animal models. This review describes existing in vivo imaging techniques used so far to visualize IAs in animal models. We systematically searched for studies containing in vivo imaging of induced IAs in animal models in PubMed and SPIE Digital library databases between 1 January 1945 and 13 July 2022. A total of 170 studies were retrieved and reviewed in detail, and information on the IA animal model, the objective of the study, and the imaging modality used was collected. A variety of methods to surgically construct or endogenously induce IAs in animals were identified, and 88% of the reviewed studies used surgical methods. The large majority of IA imaging in animals was performed for 4 reasons: basic research for IA models, testing of new IA treatment modalities, research on IA in vivo imaging of IAs, and research on IA pathophysiology. Six different imaging techniques were identified: conventional catheter angiography, computed tomography angiography, magnetic resonance angiography, hemodynamic imaging, optical coherence tomography, and fluorescence imaging. This review presents and discusses the advantages and disadvantages of all in vivo IA imaging techniques used in animal models to help future IA studies finding the most appropriate IA imaging modality and animal model to answer their research question.

Effects of medication intake on the risk of hemorrhage in patients with sporadic cerebral cavernous malformations

Objective

Recurrent intracerebral hemorrhage (ICH) poses a high risk for patients with cerebral cavernous malformations (CCMs). This study aimed to assess the influence of medication intake on hemorrhage risk in sporadic CCMs.

Methods

From a database of 1,409 consecutive patients with CCM (2003-2021), subjects with sporadic CCMs and complete magnetic resonance imaging data were included. We evaluated the presence of ICH as a mode of presentation, the occurrence of ICH during follow-up, and medication intake, including beta blockers, statins, antithrombotic therapy, and thyroid hormones. The impact of medication intake on ICH at presentation was calculated using univariate and multivariate logistic regression with age and sex adjustment. The longitudinal cumulative 5-year risk for (re-)hemorrhage was analyzed using the Kaplan-Meier curves and the Cox regression analysis.

Results

A total of 1116 patients with CCM were included. Logistic regression analysis showed a significant correlation (OR: 0.520, 95% CI: 0.284-0.951, p = 0.034) between antithrombotic therapy and ICH as a mode of presentation. Cox regression analysis revealed no significant correlation between medication intake and occurrence of (re-)hemorrhage (hazard ratios: betablockers 1.270 [95% CI: 0.703-2.293], statins 0.543 [95% CI: 0.194-1.526], antithrombotic therapy 0.507 [95% CI: 0.182-1.410], and thyroid hormones 0.834 [95% CI: 0.378-1.839]).

Conclusion

In this observational study, antithrombotic treatment was associated with the tendency to a lower rate of ICH as a mode of presentation in a large cohort of patients with sporadic CCM. Intake of beta blockers, statins, and thyroid hormones had no effect on hemorrhage as a mode of presentation. During the 5-year follow-up period, none of the drugs affected the further risk of (re-)hemorrhage.

Levosimendan as a therapeutic strategy to prevent neuroinflammation after aneurysmal subarachnoid hemorrhage?

BACKGROUND

Poor patient outcomes after aneurysmal subarachnoid hemorrhage (SAH) occur due to a multifactorial process, mainly involving cerebral inflammation (CI), delayed cerebral vasospasm (DCVS), and delayed cerebral ischemia, followed by neurodegeneration. CI is mainly triggered by enhanced synthesis of serotonin (5-HT), prostaglandin F2alpha (PGF2a), and cytokines such as interleukins. Levosimendan (LV), a calcium-channel sensitizer, has already displayed anti-inflammatory effects in patients with severe heart failure. Therefore, we wanted to elucidate its potential anti-inflammatory role on the cerebral vasculature after SAH.

METHODS

Experimental SAH was induced by using an experimental double-hemorrhage model. Sprague Dawley rats were harvested on day 3 and day 5 after the ictus. The basilar artery was used for isometric investigations of the muscular media tone. Vessel segments were either preincubated with LV or without, with precontraction performed with 5-HT or PGF2a followed by application of acetylcholine (ACh) or LV.

RESULTS

After preincubation with LV 10^-4 M and 5-HT precontraction, ACh triggered a strong vasorelaxation in sham segments (LV 10^-4 M, E_max 65%; LV 10^-5 M, E_max 48%; no LV, E_max 53%). Interestingly, SAH D3 (LV 10^-4, E_max 76%) and D5 (LV 10^-4, E_max 79%) segments showed greater vasorelaxation compared with sham. An LV series after PGF2a precontraction showed significantly enhanced relaxation in the sham (P=0.004) and SAH groups (P=0.0008) compared with solvent control vessels.

CONCLUSIONS

LV application after SAH seems to beneficially influence DCVS by antagonizing 5-HT- and PGF2a-triggered vasoconstriction. Considering this spasmolytic effect, LV might have a role in the treatment of SAH, additionally in selected patients suffering takotsubo cardiomyopathy.