Systematic review of antifibrinolytic treatment in aneurysmal subarachnoid haemorrhage

Antifibrinolytic therapy for aneurysmal subarachnoid haemorrhage

BACKGROUND

Rebleeding is an important cause of death and disability in people with aneurysmal subarachnoid haemorrhage. Rebleeding is probably related to the dissolution of the blood clot at the site of the aneurysm rupture by natural fibrinolytic activity. This review is an update of previously published Cochrane Reviews.

OBJECTIVES

To assess the effects of antifibrinolytic treatment in people with aneurysmal subarachnoid haemorrhage.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (May 2022), CENTRAL (in the Cochrane Library 2021, Issue 1), MEDLINE (December 2012 to May 2022), and Embase (December 2012 to May 2022). In an effort to identify further published, unpublished, and ongoing studies, we searched reference lists and trial registers, performed forward tracking of relevant references, and contacted drug companies (the latter in previous versions of this review).

SELECTION CRITERIA

Randomised trials comparing oral or intravenous antifibrinolytic drugs (tranexamic acid, epsilon amino-caproic acid, or an equivalent) with control in people with subarachnoid haemorrhage of suspected or proven aneurysmal cause.

DATA COLLECTION AND ANALYSIS

Two review authors (MRG & WJD) independently selected trials for inclusion, and extracted the data for the current update. In total, three review authors (MIB & MRG in the previous update; MRG & WJD in the current update) assessed risk of bias. For the primary outcome, we dichotomised the outcome scales into good and poor outcome, with poor outcome defined as death, vegetative state, or (moderate) severe disability, assessed with either the Glasgow Outcome Scale or the Modified Rankin Scale. We assessed death from any cause, rates of rebleeding, delayed cerebral ischaemia, and hydrocephalus per treatment group. We expressed effects as risk ratios (RR) with 95% confidence intervals (CI). We used random-effects models for all analyses. We assessed the quality of the evidence with GRADE.

MAIN RESULTS

We included one new trial in this update, for a total of 11 included trials involving 2717 participants. The risk of bias was low in six studies. Five studies were open label, and we rated them at high risk of performance bias. We also rated one of these studies at high risk for attrition and reporting bias.  Five trials reported on poor outcome (death, vegetative state, or (moderate) severe disability), with a pooled risk ratio (RR) of 1.03 (95% confidence interval (CI) 0.94 to 1.13; P = 0.53; 5 trials, 2359 participants; high-quality evidence), which showed no difference between groups. All trials reported on death from all causes, which showed no difference between groups, with a pooled RR of 1.02 (95% CI 0.90 to 1.16; P = 0.77; 11 trials, 2717 participants; high-quality evidence). In trials that combined short-term antifibrinolytic treatment (< 72 hours) with preventative measures for delayed cerebral ischaemia, the RR for poor outcome was 0.98 (95% CI 0.81 to 1.18; P = 0.83; 2 trials, 1318 participants; high-quality evidence).  Antifibrinolytic treatment reduced the risk of rebleeding, reported at the end of follow-up (RR 0.65, 95% CI 0.47 to 0.91; P = 0.01; 11 trials, 2717 participants; absolute risk reduction 7%, 95% CI 3 to 12%; moderate-quality evidence), but there was heterogeneity (I² = 59%) between the trials. The pooled RR for delayed cerebral ischaemia was 1.27 (95% CI 1.00 to 1.62; P = 0.05; 7 trials, 2484 participants; moderate-quality evidence). However, this effect was less extreme after the implementation of ischaemia preventative measures and < 72 hours of treatment (RR 1.10, 95% CI 0.83 to 1.46; P = 0.49; 2 trials, 1318 participants; high-quality evidence). Antifibrinolytic treatment showed no effect on the reported rate of hydrocephalus (RR 1.09, 95% CI 0.99 to 1.20; P = 0.09; 6 trials, 1992 participants; high-quality evidence).

AUTHORS' CONCLUSIONS

The current evidence does not support the routine use of antifibrinolytic drugs in the treatment of people with aneurysmal subarachnoid haemorrhage. More specifically, early administration with concomitant treatment strategies to prevent delayed cerebral ischaemia does not improve clinical outcome. There is sufficient evidence from multiple randomised controlled trials to incorporate this conclusion in treatment guidelines.

Antifibrinolytic therapy for aneurysmal subarachnoid haemorrhage

BACKGROUND

Rebleeding is an important cause of death and disability in people with aneurysmal subarachnoid haemorrhage. Rebleeding is probably related to dissolution of the blood clot at the site of aneurysm rupture by natural fibrinolytic activity. This review is an update of a previously published Cochrane review.

OBJECTIVES

To assess the effects of antifibrinolytic treatment in people with aneurysmal subarachnoid haemorrhage.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (February 2013), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 1), MEDLINE (1948 to December 2012), and EMBASE (1947 to December 2012). In an effort to identify further published, unpublished, and ongoing studies we searched reference lists and trial registers, performed forward tracking of relevant references and contacted drug companies.

SELECTION CRITERIA

Randomised trials comparing oral or intravenous antifibrinolytic drugs (tranexamic acid, epsilon amino-caproic acid, or an equivalent) with control in people with subarachnoid haemorrhage of suspected or proven aneurysmal cause.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion and extracted the data. Three review authors assessed trial quality. For the primary outcome we converted the outcome scales between good and poor outcome for the analysis. We scored death from any cause and rates of rebleeding, cerebral ischaemia, and hydrocephalus per treatment group. We expressed effects as risk ratios (RR) with 95% confidence intervals (CI). We used random-effects models for all analyses.

MAIN RESULTS

We included 10 trials involving 1904 participants. The risk of bias was low in six studies. Four studies were open label and were rated as high risk of performance bias. One of these studies was also rated as high risk for attrition bias. Four trials reported on poor outcome (death, vegetative state, or severe disability) with a pooled risk ratio (RR) of 1.02 (95% confidence interval (CI) 0.91 to 1.15). All trials reported on death from all causes with a pooled RR of 1.00 (95% CI 0.85 to 1.18). In a trial that combined short-term antifibrinolytic treatment (< 72 hours) with preventative measures for cerebral ischaemia the RR for poor outcome was 0.85 (95% CI 0.64 to 1.14). Antifibrinolytic treatment reduced the risk of re-bleeding reported at the end of follow-up (RR 0.65, 95% CI 0.44 to 0.97; 78 per 1000 participants), but there was heterogeneity (I² = 62%) between the trials. The pooled RR for reported cerebral ischaemia was 1.41 (95% CI 1.04 to 1.91, 83 per 1000 participants), again with heterogeneity between the trials (I² = 52%). Antifibrinolytic treatment showed no effect on the reported rate of hydrocephalus in five trials (RR 1.11, 95% CI 0.90 to 1.36).

AUTHORS' CONCLUSIONS

The current evidence does not support the use of antifibrinolytic drugs in the treatment of people with aneurysmal subarachnoid haemorrhage, even in those who have concomitant treatment strategies to prevent cerebral ischaemia. Results on short-term treatment are promising, but not conclusive. Further randomised trials evaluating short-term antifibrinolytic treatment are needed to evaluate its effectiveness.

Rapid administration of antifibrinolytics and strict blood pressure control for intracerebral hemorrhage

OBJECTIVE

Hematoma growth is a major cause of poor outcome in patients with intracerebral hemorrhage. We evaluated the efficacy of a combination of rapid antifibrinolytic therapy and strict blood pressure control for prevention of hematoma growth in this retrospective study.

METHODS

Systolic blood pressure was strictly controlled below 150 mm Hg by use of intravenously administered nicardipine (BPC). Prolonged infusion of antifibrinolytic therapy was given by intravenous administration of 1 g tranexamic acid over a period of 6 hours (PAF). Rapid administration of antifibrinolytic therapy was given by intravenous administration of 2 g tranexamic acid over a period of 10 minutes (RAF). Immediately after diagnosis of intracerebral hemorrhage on computed tomographic scan, 156 patients who were admitted within 24 hours of onset were treated with either a combination of PAF and BPC (PAF group) or a combination of RAF and BPC (RAF group). The incidence of hematoma growth determined by a second computed tomographic scan the day after admission was compared between the PAF and the RAF groups.

RESULTS

Hematoma growth was observed in 11 (17.5%) of 63 patients in the PAF group and 4 (4.3%) of 93 patients in the RAF group using a 20% cutoff value for hematoma enlargement. The RAF group showed a significantly low incidence of hematoma growth compared with the PAF group (P < 0.05). Between the two groups, there was no significant difference in any of the other factors reported to affect hematoma growth.

CONCLUSION

The combination of rapid administration of antifibrinolytics and strict blood pressure control may prevent hematoma growth in patients with intracerebral hemorrhage.

Plasminogen Activator Inhibitor-1 4G Allele in the 4G/5G Promoter Polymorphism Increases the Occurrence of Cerebral Ischemia After Aneurysmal Subarachnoid Hemorrhage

BACKGROUND AND PURPOSE

In several acute life-threatening diseases, the 4G-allele in the 4G/5G-promotor polymorphism in the plasminogen activator inhibitor-1 (PAI-1) gene is associated with higher PAI-1 levels and increased poor outcome, probably by promoting the formation of microthrombi. The aim of the present study was to investigate whether the PAI-1 4G/5G polymorphism is associated with the occurrence of cerebral ischemia, rebleeding, and other events, and clinical outcome after aneurysmal subarachnoid hemorrhage.

METHODS

DNA was collected and analyzed in 126 patients with aneurysmal subarachnoid hemorrhage admitted to the Academic Medical Centre Amsterdam and University Medical Centre Utrecht in the Netherlands. All episodes of deterioration were classified according to predefined criteria. Causes of poor outcome and functional outcome were assessed 3 months after the initial bleeding according to the 5-point Glasgow Outcome Scale (GOS).

RESULTS

Secondary ischemia occurred more often in patients with the 4G genotype than in patients homozygous for the 5G allele (RR: 3.3; 95% CI: 1.1 to 10.0). No significant differences were found between the groups for rebleeding or other events. Patients with the 4G genotype tended to have a higher risk for poor outcome than patients with the 5G/5G genotype (RR 1.2; 95% CI 0.7 to 2.2).

CONCLUSIONS

The 4G allele in the PAI-1 gene increases the risk for cerebral ischemia after aneurysmal subarachnoid hemorrhage (SAH) and probably also the risk for poor outcome. After early aneurysm occlusion, treatment aimed at enhancing fibrinolysis might be effective to prevent and treat cerebral ischemia in patients with aneurysmal SAH.

Perioperative blood and blood product management for spinal deformity surgery

BACKGROUND CONTEXT

Spinal deformity surgery, like many other orthopedic procedures, involves significant operative blood loss. In order to avoid the necessity of bank blood transfusions, many blood management strategies have been devised.

PURPOSE

The goal of this review is to analyze the utility of current blood management strategies.

STUDY DESIGN/SETTING

Review paper.

METHODS

Using Medline reviews, pertinent data on blood management agents and strategies were assembled.

RESULTS

Techniques can be organized into preoperative, intraoperative and postoperative categories. Preoperative techniques include autologous blood donation and red cell augmentation. In addition to some established surgical and anesthesia techniques, recent pharmacologic agents have become available to include thrombotic agents and antifibrinolytics, which surgeons may add to their intraoperative armamentarium. A brief mention of postoperative blood salvage drains is also included.

CONCLUSIONS

The judicious use of the agents and techniques can significantly reduce the need for blood transfusions in the setting of spinal deformity surgery.

Antifibrinolytic therapy for aneurysmal subarachnoid haemorrhage

BACKGROUND

Rebleeding is an important cause of death and disability in people with aneurysmal subarachnoid haemorrhage. Rebleeding is probably due to dissolution of the clot by natural fibrinolytic activity.

OBJECTIVES

The objective of this review was to assess the effect of antifibrinolytic treatment in patients with aneurysmal subarachnoid haemorrhage.

SEARCH STRATEGY

We searched the Cochrane Stroke Group Trials Register, the Cochrane Controlled Trials Register, Medline and Embase (last searched June 2002) and reference lists of articles. We also contacted drug companies.

SELECTION CRITERIA

Randomised trials comparing oral or intravenous antifibrinolytic drugs (tranexamic acid, epsilon amino-caproic acid or an equivalent) with control in people with confirmed subarachnoid haemorrhage.

DATA COLLECTION AND ANALYSIS

Two reviewers independently selected trials for inclusion and extracted the data. All five reviewers assessed trial quality.

MAIN RESULTS

Nine trials involving 1399 patients were included. Based on 1041 patients in three trials, antifibrinolytic treatment did not show any evidence of benefit for poor outcome (death, vegetative state or severe disability) with an odds ratio of 1.12, 95% confidence interval 0.88 to 1.43. Death from all causes was not significantly influenced by treatment across all nine trials (odds ratio 0.99, 95% confidence interval 0.79 to 1.24). Antifibrinolytic treatment reduced the risk of re-bleeding reported at the end of follow-up, with some heterogeneity between the trials (odds ratio 0.55, 95% confidence interval 0.42 to 0.71). Treatment increased the risk of cerebral ischaemia in five trials (odds ratio 1.39, 95% confidence interval 1.07 to 1.82) with considerable heterogeneity between the most recent study (Roos 2000), in which specific treatments to prevent cerebral ischemia were used, and the four older studies. Antifibrinolytic treatment showed no effect on the reported rate of hydrocephalus in five trials (odds ratio 1.14, 95% confidence interval 0.86 to 1.51).

REVIEWER'S CONCLUSIONS

Treatment does not improve clinical outcome because the benefit is offset by an increase in poor outcome caused by cerebral ischemia as a result of treatment with antifibrinolytics. These data do not support the routine use of antifibrinolytic drugs in the treatment of patients with aneurysmal subarachnoid haemorrhage.

Nimodipine increases fibrinolytic activity in patients with aneurysmal subarachnoid hemorrhage

BACKGROUND AND PURPOSE

The purpose of this study was first, to investigate which factor in the fibrinolytic cascade is responsible for the recently observed increase of fibrinolytic activity in patients with aneurysmal subarachnoid hemorrhage (SAH), and second, the cause of this increase.

METHODS

Fibrinolytic activity and the main regulators of endogenous fibrinolytic activity, tissue plasminogen activator, and plasminogen activator inhibitor 1 (PAI-1) were measured in patients treated with and without nimodipine.

RESULTS

In patients with aneurysmal SAH, fibrinolytic activity significantly increases from 2.7 IU/mL on admission to 4.2 IU/mL in week 3 (P<0.01, paired-sample t test), caused by a 1.6-fold decrease in plasma levels of PAI-1. The results also show that increased fibrinolytic activity is seen only in patients treated with nimodipine and that plasminogen activity and PAI-1 returned to baseline levels after treatment with nimodipine had been discontinued.

CONCLUSIONS

The mechanism of increased fibrinolytic activity in patients with aneurysmal SAH is a decrease in the level of PAI-1, which is most likely caused by treatment with nimodipine.

Subarachnoid haemorrhage: epidemiology, risk factors, and treatment options

The present review focuses on subarachnoid haemorrhage (SAH) secondary to the rupture of an intracranial aneurysm, a condition with a high case fatality rate. Additionally, many of the surviving patients are left with significant disabilities. Risk factors for aneurysmal SAH include both genetic and acquired conditions. The most common presenting symptom is sudden onset of severe headache. Since headache is very common in the general population, it is not unusual that SAH is misdiagnosed at its onset with often catastrophic consequences. Unlike other acute neurological disorders such as brain injury, in which patient outcome is closely related to the extent of the injury occurring at the time of the trauma, patients with aneurysmal SAH are at risk of subsequent deterioration from 'avoidable' complications such as rebleed, vasospasm, hydrocephalus, and several other non-neurological general medical complications. Thus, the critical care management of the patient with SAH is of utmost importance in order to maximise the chances of satisfactory recovery. Although surgical clipping of the ruptured aneurysm remains the gold standard therapy, with the continuing refinement of endovascular techniques, a new, 'less invasive' option is now available, especially for patients considered poor surgical candidates.