The effects of continuous prostacyclin infusion on regional blood flow and cerebral vasospasm following subarachnoid haemorrhage: study protocol for a randomised controlled trial

Plasma Levels of IL-6, IL-8, IL-10, ICAM-1, VCAM-1, IFNγ, and TNFα are not Associated with Delayed Cerebral Ischemia, Cerebral Vasospasm, or Clinical Outcome in Patients with Subarachnoid Hemorrhage

BACKGROUND

Delayed cerebral ischemia (DCI) is a serious and frequent complication following subarachnoid hemorrhage (SAH). The pathophysiology behind DCI remains poorly understood, but inflammation has been proposed to play a significant role. This study investigated the relationship between plasma levels of some of the most important inflammatory markers and DCI, cerebral vasospasm, and functional outcome in patients with SAH.

METHODS

In 90 patients with SAH, interleukin-6, intercellular adhesion molecule-1, vascular cell adhesion molecule-1, high sensitivity C-reactive protein (HsCRP), interleukin-8, interleukin-10, interferon gamma, and tumor necrosis factor alpha were measured in peripheral blood day 3 and day 8 after SAH. Any occurrence of DCI or infection was recorded, and computed tomography angiography was performed on day 8. Clinical outcome was assessed after 3 months.

RESULTS

HsCRP on day 3 was higher in patients with angiographic vasospasm (P = 0.003), and HsCRP on day 8 was higher in patients with poor outcome (P = 0.014). No association with DCI, vasospasm, or outcome was found for any of the remaining analyzed substances.

CONCLUSIONS

High plasma levels of HsCRP were significantly associated with angiographic vasospasm and clinical outcome. Plasma levels of interleukin-6, vascular cell adhesion molecule-1, intercellular adhesion molecule-1, interleukin-8, interleukin-10, interferon gamma, and tumor necrosis factor alpha were not associated with DCI, angiographic vasospasm, or clinical outcome at 3 months.

Effect of delayed onset prostacyclin on markers of endothelial function and damage after subarachnoid hemorrhage

BACKGROUND

Subarachnoid hemorrhage (SAH) is a neurological emergency. Delayed ischemic neurological deficit is one of the main causes of poor outcome after SAH and is probably caused, at least in part, by cerebral vasospasm. The pathophysiology of this is multifaceted, but endothelial damage and activation as well as glycocalyx damage have been implicated. Prostacyclin has been shown to protect damaged and activated endothelium and to facilitate glycocalyx repair. We investigated biomarkers of endothelial activation and damage in patients with SAH randomized to 5 days prostacyclin infusion or placebo.

METHODS

Patients with aneurysmal SAH managed by coiling or surgery, and a World Federation of Neurological Surgeons score between 1 and 4, and Fisher grade 3 or 4, were treated with a continuous low-dose intravenous prostacyclin infusion or placebo initiated on day 5 and discontinued on day 10 after SAH. Blood samples were drawn from the patients before, during and after prostacyclin/placebo infusion. Soluble biomarkers of endothelial cell activation (sE-selectin, sVE-cadherin) and damage (sTM), glycocalyx damage (syndecan-1) and sympathoadrenal activation (adrenaline, noradrenaline), were measured by ELISA.

RESULTS

Ninety patients were randomized. Prostacyclin infusion influenced neither biomarkers of sympathoadrenal activation, endothelial activation and damage nor biomarkers of endothelial glycocalyx breakdown.

CONCLUSIONS

We did not find any effects on markers of sympathoadrenal activation, endothelial damage and activation, or glycocalyx degradation of delayed onset prostacyclin infusion compared to placebo. Further trials investigating early onset endothelial repair using prostacyclin are warranted.

Effects of continuous prostacyclin infusion on regional blood flow and cerebral vasospasm following subarachnoid haemorrhage: statistical analysis plan for a randomized controlled trial

Background

One of the main causes of mortality and morbidity following subarachnoid hemorrhage (SAH) is the development of cerebral vasospasm, a frequent complication arising in the weeks after the initial bleeding. Despite extensive research, no effective treatment of vasospasm exists to date. Prostacyclin is a potent vasodilator and inhibitor of platelet aggregation. In vitro models have shown a relaxing effect of prostacyclin after induced contraction in cerebral arteries, and a recent pilot trial showed a positive effect on cerebral vasospasm in a clinical setting. No randomized clinical trials have investigated the possible pharmacodynamic effects of prostacyclin on the human brain following SAH.

Methods/Design

This trial is a single centre, randomized, placebo-controlled, parallel group, double blinded, clinical pilot trial. A total of 90 patients with SAH will be randomized to one of three intervention arms: epoprostenol at 1 ng/kg/min, epoprostenol at 2 ng/kg/min, or placebo in addition to the standard treatment. Trial medication will start on Day 5 after SAH and continue to Day 10. The primary outcome measure is changes in cerebral blood flow measured by a computed tomography (CT) perfusion scan. The secondary outcomes are vasospasm measured by a CT angiography, regional blood flow, clinical symptoms of cerebral ischemia, and outcome at three months (Glasgow Outcome Scale).

Discussion

The primary outcome has been altered slightly since the publication of our study protocol. Global cerebral blood flow is now primary outcome, whereas regional blood flow is a secondary outcome.

Trial registration

Clinicaltrials.gov NCT01447095. Registration date: 11 October 2011.

Cerebral vasospasm pharmacological treatment: an update

Aneurysmal subarachnoid hemorrhage- (aSAH-) associated vasospasm constitutes a clinicopathological entity, in which reversible vasculopathy, impaired autoregulatory function, and hypovolemia take place, and lead to the reduction of cerebral perfusion and finally ischemia. Cerebral vasospasm begins most often on the third day after the ictal event and reaches the maximum on the 5th-7th postictal days. Several therapeutic modalities have been employed for preventing or reversing cerebral vasospasm. Triple "H" therapy, balloon and chemical angioplasty with superselective intra-arterial injection of vasodilators, administration of substances like magnesium sulfate, statins, fasudil hydrochloride, erythropoietin, endothelin-1 antagonists, nitric oxide progenitors, and sildenafil, are some of the therapeutic protocols, which are currently employed for managing patients with aSAH. Intense pathophysiological mechanism research has led to the identification of various mediators of cerebral vasospasm, such as endothelium-derived, vascular smooth muscle-derived, proinflammatory mediators, cytokines and adhesion molecules, stress-induced gene activation, and platelet-derived growth factors. Oral, intravenous, or intra-arterial administration of antagonists of these mediators has been suggested for treating patients suffering a-SAH vasospam. In our current study, we attempt to summate all the available pharmacological treatment modalities for managing vasospasm.