Association Between Aspirin Use and Risk of Aneurysmal Subarachnoid Hemorrhage: A Meta-analysis

Circular RNAs in intracranial aneurysms: Emerging roles in pathogenesis, diagnosis and therapeutic intervention

Intracranial aneurysms (IAs) present a substantial health threat, given the potential for catastrophic ruptures and subarachnoid hemorrhages (SAH). Swift and effective measures for diagnosis and treatment are paramount to enhance patient outcomes and alleviate the associated healthcare burden. In this context, circular RNAs (circRNAs) have emerged as an intriguing area of investigation, offering promise as both diagnostic biomarkers and therapeutic targets for IAs. CircRNAs have demonstrated their influence on critical molecular and cellular processes underpinning IAs pathogenesis, revealing their pivotal role in understanding this complex ailment. Beyond their diagnostic potential, circRNAs hold great potential as prognostic markers, providing crucial insights into IAs rupture risk. The unique circular structure and their regulatory functions make circRNAs an enticing avenue for innovative therapeutic approaches. The ongoing study of circRNAs in the context of IAs is an exciting and rapidly evolving field that has the potential to revolutionize approaches to diagnosis, treatment, and prevention of this life-threatening condition. As research continues to unravel the intricate roles of circRNAs, they are poised to become invaluable tools in clinical practice, enhancing patient care and ultimately reducing the impact of cerebral aneurysms on both individuals and healthcare systems. This comprehensive review delves deeply into the world of circRNAs in the realm of IAs, elucidating their multifaceted roles in the onset and progression of this condition. Moreover, this review ventures into the diagnosis and therapeutic potential of circRNAs, exploring their possible applications in gene therapy and as targets for novel treatment modalities.

The association between acetylsalicylic acid and subarachnoid haemorrhage: the Framingham Heart Study

Studies investigating the association between acetylsalicylic acid (ASA) use and spontaneous subarachnoid haemorrhage (SAH) in the general population have produced conflicting results. The aim of this study is to clarify the relationship between SAH and ASA. We included all participants who reported on ASA use during interim examinations of the Framingham Heart Study Cohorts. Using Cox proportional-hazards regression modelling, we estimated the hazard ratio (HR) associated with ASA use. 7692 participants were included in this study. There were 30 cases of SAH during follow up, with an estimated incidence of 10.0 per 100,000 person- years (CI 6.90-14.15). Univariate analysis showed no association between regular ASA use and SAH (HR, 0.33 [0.08-1.41]; p = 0.14). This was similar when accounting for smoking (HR, 0.35 [0.08-1.51]; p = 0.16). Using a large longitudinal dataset from the Framingham Heart Study, we observed some evidence suggesting fewer SAH in those participants taking regular ASA. However, multivariate statistical analysis showed no significant association between ASA use and SAH. Due to the low incidence of SAH in the general population, the absolute number of SAH events was low and it remains uncertain if a significant effect would become apparent with more follow up.

Sex Differences in Cerebral Aneurysms and Subarachnoid Hemorrhage

Sex differences in cerebral aneurysm occurrence and characteristics have been well described. Although sex differences in outcomes following ischemic stroke have been identified, the effect of sex on outcomes following hemorrhagic stroke, and in particular, aneurysm treatment has been less studied. We describe the current state of knowledge regarding the impact of sex on treatment and outcomes of cerebral aneurysms. Although prior studies suggest that aneurysm prevalence and progression may be related to sex, we did not find clear evidence that outcomes following subarachnoid hemorrhage vary based on sex. Last, we identify areas for future research that could enhance understanding of the role sex plays in this context.

Aspirin and growth, rupture of unruptured intracranial aneurysms: A systematic review and meta-analysis

OBJECTIVES

Aspirin has been suggested as a potential therapeutic strategy to prevent the growth and rupture of unruptured intracranial aneurysms (UIAs), but there is still controversy. The aim of this systematic review and meta-analysis is to determine the association between aspirin use and growth, rupture of UIAs.

METHODS

We performed a systematic literature search of electronic databases to identify cohort and case-control studies investigating the relationship between aspirin use and growth or rupture of UIAs. Pooled odds ratio (OR) with corresponding 95% confidence interval (CI) were calculated using a random effects model. Heterogeneity among studies was quantified using the I² statistic, and potential publication bias was assessed using funnel plots. Sensitivity analysis was performed to verify the robustness of the intention-to-treat results. Subgroup analysis was conducted according to the frequency of aspirin use.

RESULTS

We identified 8 studies comprising 10,518 participants. The risk of bias was low to moderate. The pooled estimate showed that aspirin use was associated with a lower likelihood of growth of UIAs (OR = 0.25, 95% CI = 0.11-0.55; p = 0.0005) without statistical heterogeneity (p for Cochran Q statistic = 0.62, I² = 0%). Likewise, aspirin intake also significant decreased 58% risk of intracranial aneurysms rupture (OR = 0.42, 95% CI = 0.29-0.60; p < 0.00001) with moderate heterogeneity (p for Cochran Q statistic = 0.005, I² = 66%). Similar results were observed in the sensitivity analysis. Pooled OR of aspirin frequency subgroup analysis for less than or equal to 2 times per week was 0.82 (95%CI = 0.40-1.72; I² = 0%), for at least 3 times per week to daily was 0.25 (95%CI = 0.12-053; I² = 0%), for daily was 0.59 (95%CI: 0.47-0.74; I² = 0%), and for unknown was 0.26 (95%CI: 0.15-0.45; I² = 51%).

CONCLUSIONS

The results of this systematic review and meta-analysis indicates a beneficial effect of aspirin on growth and rupture of UIAs.

A meta-analysis of aspirin and subarachnoid hemorrhage in patients with intracranial aneurysms yields different results to the general population

BACKGROUND

Some studies have shown a protective association between aspirin use and subarachnoid hemorrhage. Other studies have found no relationship or the reverse. These studies differ in their study populations and definitions of subarachnoid hemorrhage.

AIMS

Our aim was to establish (1) if there is an association between aspirin and subarachnoid hemorrhage, (2) how this differs between the general population and those with intracranial aneurysms.

SUMMARY OF REVIEW

Studies reporting aspirin use and the occurrence of subarachnoid hemorrhage were included and grouped based on population (general population vs. aneurysm population). Odds ratios, hazard ratios, and confidence intervals were combined in random-effects models. Eleven studies were included. Overall, there was an association between aspirin and subarachnoid hemorrhage (OR 0.68 [0.48, 0.96]). However, populations were diverse and heterogeneity between studies high (p < 0.00001), questioning the validity of combining these studies and justifying analysis by population. In the general population, there was no difference in aspirin use between individuals with and without subarachnoid hemorrhage (OR 1.15 [0.96, 1.38]). In patients with intracranial aneurysms, aspirin use was greater in patients without subarachnoid hemorrhage (OR 0.37 [0.24, 0.58]), although these studies were at higher risk of bias.

CONCLUSIONS

There is an association between aspirin use and subarachnoid hemorrhage in patients with intracranial aneurysms. This apparent protective relationship is not seen in the general population. Prospective randomized studies are required to further investigate the effect of aspirin on unruptured intracranial aneurysms.

The Role of Aspirin in the Management of Intracranial Aneurysms: A Systematic Review and Meta-Analyses

Objective: To evaluate the association between aspirin use and the risks of unruptured intracranial aneurysm (UIA) growth and aneurysmal subarachnoid hemorrhage (aSAH).

Methods: We searched PubMed and Scopus from inception to 1 September 2020. Studies evaluating the associations between aspirin prescription and the risk of UIA growth or the risk of aSAH were included. The study only included patients with intracranial aneurysms. We assessed the quality of included studies using the Newcastle-Ottawa scale. Random-effects meta-analysis was conducted to pool the estimates of effect size quantitatively. Sensitivity analyses using the leave-one-out strategy were performed to identify any potential source of heterogeneity.

Results: After a review of 2,226 citations, five cohort studies, two case-control studies, and one nested case-control study involving 8,898 participants were included. Pooled analyses showed that aspirin use, regardless of frequency and duration, was associated with a statistically significantly lower risk of UIA growth (OR 0.25, 95% CI 0.11–0.54; I² = 0.0%, p = 0.604) and aSAH (OR, 0.37, 95% CI, 0.23–0.58; I² = 79.3%, p = 0.001) in patients presented with intracranial aneurysms. The results did not significantly change in sensitivity analyses.

Conclusions: Summarizing available evidence in the literature, our findings indicate that aspirin use, regardless of frequency and duration, was associated with a statistically significantly lower risk of UIA growth and aSAH in patients with UIA. Well-designed and large-scale clinical trials are needed to help define the role of aspirin as a protective pharmaceutical for UIAs.

Relationship between aspirin use and subarachnoid hemorrhage: A systematic Review and meta-analysis

BACKGROUND

Aspirin has been associated with a decreasing risk of subarachnoid hemorrhage due to its anti-inflammatory mechanism of action and potential protective properties against aneurysm growth.

OBJECTIVE

To determine the association between aneurysmal subarachnoid hemorrhage and aspirin use.

METHODS

A systematic review of the literature and a meta-analysis were performed across the PubMed database. The following keywords were used: "aspirin, acetylsalicylic acid, 2-acetyloxy-benzoic acid, ruptured intracranial aneurysm, aneurysmal subarachnoid hemorrhage, spontaneous subarachnoid hemorrhage, intracerebral hemorrhage, spontaneous aneurysmal hemorrhage, spontaneous intracerebral bleeding". Studies that were performed with animals or analyzed patients with traumatic brain injury were excluded. A total of five studies were included in our meta-analysis, with a total of 19,222 patients evaluated. Statistical analysis was performed to determine the association between the use of aspirin and the risk of subarachnoid hemorrhage.

RESULTS

Aspirin use reduce the risk of subarachnoid hemorrhage (odds ratio [OR] 0.51, 95 % confidence interval [CI] 0.34-0.76).

CONCLUSION

Although some previous studies suggested that aspirin may potentially reduce the risk of subarachnoid hemorrhage, our meta-analysis found an association between the reduction of risk of aneurysmal subarachnoid hemorrhage.

Complete spontaneous thrombosis in unruptured non-giant intracranial aneurysms: A case report and systematic review

BACKGROUND AND AIM

Spontaneous partial or complete thrombosis of saccular unruptured intracranial aneurysm (UIAs) is a known occurrence in giant aneurysms. However, spontaneous complete thrombosis of non-giant aneurysms is a rare event in the natural history of UIAs. The aim of this paper is to report on the cases from literature of complete spontaneous thrombosis with a view to identify possible factors associated with this phenomenon.

MATERIAL AND METHODS

We performed a systematic review of the current literature on spontaneous complete thrombosis of saccular, non-giant, unruptured UIAs, including a case that we treated at our institution. We analysed the possible risk factors for thrombosis, association with ischemic events, rupture and recanalization. We reviewed the possible management's strategies for this group of patients described in literature to date.

RESULTS

We identified 26 patients for a total of 27 thrombosed aneurysms from the literature review (including our case). Thrombosis was prevalent in women, in the anterior circulation and in larger aneurysms. Endovascular events in the parent artery, either spontaneous or iatrogenic, were associated with spontaneous thrombosis in 4 cases. In 47 % of cases an antiplatelet treatment (AP) was introduced. Rupture and recanalization of the aneurysm were observed in 14 % and 33 % respectively. A larger size was the only factor statistically associated with rupture (P = 0041). AP was not statistically associated with recanalization or rupture of the aneurysm.

CONCLUSION

Complete spontaneous thrombosis is not a curative event. Its natural history is associated with recanalization, rupture and ischemic stroke. Conservative treatment with a clinical-radiological follow up and treatment with AP is a safe option for small aneurysms. Definitive aneurysmal exclusion should be considered in medium and large aneurysms due to the significant risks associated with untreated aneurysms.