Intraarterial Colforsin May Improve the Outcome of Patients with Aneurysmal Subarachnoid Hemorrhage: A Retrospective Study

Intra-arterial vasodilators for vasospasm following aneurysmal subarachnoid hemorrhage: a meta-analysis

Objective

The efficacy of intra-arterial vasodilators (IADs) for the treatment of vasospasm following aneurysmal subarachnoid hemorrhage (aSAH) remains debatable. The objective of this meta-analysis was to pool estimates of angiographic and neurological response, clinical outcome, and mortality following treatment of vasospasm with IADs.

Methods

We searched PubMed, Embase, Scopus, Clinicaltrials.gov, Cochrane database, and CINAHL in December 2015 and August 2016. Studies reporting angiographic and neurological response, clinical outcome, and mortality following IAD treatment of vasospasm in 10 or more adults with aSAH were included. All established IADs were allowed. Two authors independently selected studies and abstracted the data. Mean weighted probabilities (MWP) were calculated using random effects model.

Results

Inclusion criteria were met by 55 studies (n=1571). MWP for immediate angiographic response to IAD treatment was 89% (95% CI 83% to 94%), post-IAD neurological improvement 57% (95% CI 49% to 65%), good outcome 66% (95% CI 60% to 71%), and mortality was 9% (95% CI 7% to 12%). After adjusting for publication bias, MWP for mortality was 5% (95% CI 4% to 7%). When transcranial Doppler (TCD) was used along with clinical deterioration for patient selection, rates of neurological response (64%) and good outcome (72%) were better. IADs were not superior to controls (balloon angioplasty or medical management).

Conclusion

IAD treatment leads to a robust angiographic response and fair (but lower) rates of neurological response and good clinical outcome. Mortality was lower than the average reported in the literature. Rates of neurological response and good outcome were better when TCD was used for patient selection. Carefully designed studies are needed to compare IADs against medical management and balloon angioplasty.

International Union of Basic and Clinical Pharmacology. CI. Structures and Small Molecule Modulators of Mammalian Adenylyl Cyclases

Adenylyl cyclases (ACs) generate the second messenger cAMP from ATP. Mammalian cells express nine transmembrane AC (mAC) isoforms (AC1-9) and a soluble AC (sAC, also referred to as AC10). This review will largely focus on mACs. mACs are activated by the G-protein Gαs and regulated by multiple mechanisms. mACs are differentially expressed in tissues and regulate numerous and diverse cell functions. mACs localize in distinct membrane compartments and form signaling complexes. sAC is activated by bicarbonate with physiologic roles first described in testis. Crystal structures of the catalytic core of a hybrid mAC and sAC are available. These structures provide detailed insights into the catalytic mechanism and constitute the basis for the development of isoform-selective activators and inhibitors. Although potent competitive and noncompetitive mAC inhibitors are available, it is challenging to obtain compounds with high isoform selectivity due to the conservation of the catalytic core. Accordingly, caution must be exerted with the interpretation of intact-cell studies. The development of isoform-selective activators, the plant diterpene forskolin being the starting compound, has been equally challenging. There is no known endogenous ligand for the forskolin binding site. Recently, development of selective sAC inhibitors was reported. An emerging field is the association of AC gene polymorphisms with human diseases. For example, mutations in the AC5 gene (ADCY5) cause hyperkinetic extrapyramidal motor disorders. Overall, in contrast to the guanylyl cyclase field, our understanding of the (patho)physiology of AC isoforms and the development of clinically useful drugs targeting ACs is still in its infancy.

Delayed cerebral ischaemia prevention and treatment after aneurysmal subarachnoid haemorrhage: a systematic review

: The leading cause of morbidity and mortality after surviving the rupture of an intracranial aneurysm is delayed cerebral ischaemia (DCI). We present an update of recent literature on the current status of prevention and treatment strategies for DCI after aneurysmal subarachnoid haemorrhage. A systematic literature search of three databases (PubMed, ISI Web of Science, and Embase) was performed. Human clinical trials assessing treatment strategies, published in the last 5 yr, were included based on full-text analysis. Study data were extracted using tables depicting study type, sample size, and outcome variables. We identified 49 studies meeting our inclusion criteria. Clazosentan, magnesium, and simvastatin have been tested in large high-quality trials but failed to show a beneficial effect. Cilostazol, eicosapentaenoic acid, erythropoietin, heparin, and methylprednisolone yield promising results in smaller, non-randomized or retrospective studies and warrant further investigation. Topical application of nicardipine via implants after clipping has been shown to reduce clinical and angiographic vasospasm. Methods to improve subarachnoid blood clearance have been established, but their effect on outcome remains unclear. Haemodynamic management of DCI is evolving towards euvolaemic hypertension. Endovascular rescue therapies, such as percutaneous transluminal balloon angioplasty and intra-arterial spasmolysis, are able to resolve angiographic vasospasm, but their effect on outcome needs to be proved. Many novel therapies for preventing and treating DCI after aneurysmal subarachnoid haemorrhage have been assessed, with variable results. Limitations of the study designs often preclude definite statements. Current evidence does not support prophylactic use of clazosentan, magnesium, or simvastatin. Many strategies remain to be tested in larger randomized controlled trials.

CLINICAL TRIAL REGISTRATION

This systematic review was registered in the international prospective register of systematic reviews.

PROSPERO

CRD42015019817.