No hyperfibrinolysis following subarachnoid or intracerebral haemorrhage: a prospective cohort study

Safety and Efficacy of Tranexamic Acid in Aneurysmal Subarachnoid Hemorrhage: A Meta-Analysis of Randomized Controlled Trials

Background

In recent decades, tranexamic acid (TXA) antifibrinolytic therapy before aneurysm clipping or embolization has been widely reported, but its safety and efficacy remain controversial. This meta-analysis evaluated the efficacy and safety of TXA therapy in aneurysmal subarachnoid hemorrhage (aSAH) patients, aiming to improve the evidence-based medical knowledge of treatment options for such patients.

Methods

Pubmed, Web of Science, and Cochrane Library databases were searched up to 1 March 2021 for randomized controlled trials (RCTs). We extracted safety and efficacy outcomes and performed a meta-analysis using the Review Manager software. We performed two group analyses of TXA duration and daily dose.

Results

Ten RCT studies, enrolling a total of 2,810 participants (1,410 with and 1,400 without TXA therapy), matched the selection criteria. In the TXA duration group: TXA did not reduce overall mortality during the follow-up period [RR 1.00 (95% CI 0.81–1.22)]. The overall rebleeding rate in the TXA group was 0.53 times that of the control group, which was statistically significant [RR 0.53 (95% CI 0.39–0.71)]. However, an RR of 0.43 was not statistically significant in the subgroup analysis of short-term therapy [RR 0.43 (95% CI 0.13–1.39)]. The overall incidence of hydrocephalus was significantly higher in the TXA group than in the control group [RR 1.13 (95% CI 1.02–1.24)]. However, the trend was not statistically significant in the subgroup analysis [short-term: RR 1.10 (95% CI 0.99–1.23); long-term: RR 1.22 (95% CI 0.99–1.50)]. Treatment with TXA did not cause significant delayed cerebral ischemia [RR 1.18 (95% CI 0.89–1.56)], and its subgroup analysis showed an opposite and insignificant effect [short-term: RR 0.99 (95% CI 0.79–1.25); long-term: RR 1.38 (95% CI 0.86–2.21)]. Results in the daily dose group were consistent with those in the TXA duration group.

Conclusions

Tranexamic acid does not reduce overall mortality in patients with aSAH, nor does it increase the incidence of delayed cerebral ischemia. Tranexamic acid in treating aSAH can reduce the incidence of rebleeding. However, there is no statisticalsignificance in the ultra-early short-term and low daily dose TXA therapy, which may be due to the lack of relevant studies, and more RCT experiments are needed for further study.

Systematic Review Registration:

https://www.crd.york.ac.uk/PROSPERO/display_record.asp? PROSPERO, identifier: 244079.

Nonhematologic and Hematologic Factors in Spontaneous Intracerebral Hemorrhage

Spontaneous intracerebral hemorrhage is defined as nontraumatic bleeding into the brain without vascular malformations or presence of tumor. It occurs in about a third of all strokes and has a high mortality and morbidity. Risk factors that determine the outcome are incompletely understood. Known factors include older age, male gender, Asian ethnicity, hypertension, and comorbidity such as inherited or acquired bleeding diathesis and use of antithrombotic drugs. Likewise, the clinical characteristics of the hematoma such as location and volume of the hematoma and other imaging features are also important. Hematoma extension or expansion is a complication with an unfavorable outcome. Recognition of risk factors for hematoma expansion and measures to prevent it, such as blood pressure lowering, will improve the outcome. Enhanced diagnostic methods, especially in imaging techniques developed over the past decade, have not only led to a better understanding of the pathophysiology of spontaneous intracerebral hemorrhage but also of the factors that influence hematoma expansion. An improved knowledge is essential to better management, minimizing hematoma expansion and leading to a healthier outcome.

Hemostasis and Fibrinolysis following Aneurysmal Subarachnoid Hemorrhage: A Systematic Review on Additional Knowledge from Dynamic Assays and Potential Treatment Targets

Mortality after aneurysmal subarachnoid hemorrhage (aSAH) is augmented by rebleeding and delayed cerebral ischemia (DCI). A range of assays evaluating the dynamic process of blood coagulation, from activation of clotting factors to fibrinolysis, has emerged and a comprehensive review of hemostasis and fibrinolysis following aSAH may reveal targets of treatment. We conducted a systematic review of existing literature assessing coagulation and fibrinolysis following aSAH, but prior to treatment. PubMed, Embase, and Web of Science were searched on November 18, 2020, without time boundaries. In total, 45 original studies were eventually incorporated into this systematic review, divided into studies presenting data only from conventional or quantitative assays (n = 22) and studies employing dynamic assays (n = 23). Data from conventional or quantitative assays indicated increased platelet activation, whereas dynamic assays detected platelet dysfunction possibly related to an increased risk of rebleeding. Secondary hemostasis was activated in conventional, quantitative, and dynamic assays and this was related to poor neurological outcome and mortality. Studies systematically investigating fibrinolysis were sparse. Measurements from conventional or quantitative assays, as well as dynamic fibrinolysis assays, revealed conflicting results with normal or increased lysis and changes were not associated with outcome. In conclusion, dynamic assays were able to detect reduced platelet function, not revealed by conventional or quantitative assays. Activation of secondary hemostasis was found in both dynamic and nondynamic assays, while changes in fibrinolysis were not convincingly demonstrable in either dynamic or conventional or quantitative assays. Hence, from a mechanistic point of view, desmopressin to prevent rebleeding and heparin to prevent DCI may hold potential as therapeutic options. As changes in fibrinolysis were not convincingly demonstrated and not related to outcome, the use of tranexamic acid prior to aneurysm closure is not supported by this review.