The incidence of first stroke in pregnant and non-pregnant women of childbearing age: a population-based cohort study from England

Background: Pregnant women may have an increased risk of stroke compared to non-pregnant women of similar age, but the magnitude and the timing of such risk are unclear. We examined the risk of first stroke event in women of childbearing age and compared the risk during pregnancy and in the early postpartum period to background risk outside these periods. Methods and Results: We conducted an open cohort study of 2,046,048 women aged 15-49 years between 1st April 1997 and 31th March 2014 using linked primary (Clinical Practice Research Datalink) and secondary (Hospital Episode Statistics) care records in England. Risk of first stroke was assessed by calculating the incidence rate of stroke in antepartum, peripartum (2 days before until 1 day after delivery), early (first six weeks) and late (second six weeks) postpartum periods, compared with non-pregnant time using a Poisson regression model with adjustment for maternal age, socioeconomic group and calendar time. A total of 2,511 women had a first stroke. The incidence rate of stroke was 25.0 per 100,000 person-years (95% confidence interval 24.0-26.0) in non-pregnant time. The rate was lower antepartum (10.7/100,000 person-years, 7.6-15.1), but 9-fold higher peripartum (161.1/100,000 person-years, 80.6-322.1) and 3-fold higher early postpartum (47.1/100,000 person-years, 31.3-70.9). Rates of ischaemic and haemorrhagic stroke both increased peripartum and early postpartum. Conclusions: Although the absolute risk of first stroke is low in women of childbearing age, health care professionals should be aware of a considerable increase in relative risk during the peripartum and early postpartum periods

Therapeutic potential of transdermal glyceryl trinitrate in the management of acute stroke

The nitric oxide donor, glyceryl trinitrate (GTN), is a candidate treatment for the management of acute stroke with haemodynamic and potential reperfusion and neuroprotective effects. When administered as a transdermal patch during the acute and subacute phases after stroke, GTN was safe, lowered blood pressure, maintained cerebral blood flow, and did not induce cerebral steal or alter functional outcome. However, when given within 6 h of stroke onset, GTN reduced death and dependency (odds ratio 0.52; 95% confidence interval 0.34–0.78), death, disability, cognitive impairment and mood disturbance, and improved quality of life (data from two trials, n = 312). In a pooled analysis of four studies (n = 186), GTN reduced between-visit systolic blood pressure variability over days 1–7 compared with no GTN (mean difference -2.09; 95% confidence interval -3.83 to -0.35; p = 0.019). The efficacy of GTN given in the ultra-acute/pre-hospital setting is currently being assessed and, if found to be beneficial, the implications for hyperacute stroke practice are significant. Here, we discuss the evidence to date, potential mechanisms of action and future possibilities, including unanswered questions, for the therapeutic potential of GTN in acute stroke

Statistical analysis plan for the ‘Triple Antiplatelets for Reducing Dependency after Ischaemic Stroke’ (TARDIS) trial

Rationale: Antiplatelet agents such as aspirin, clopidogrel and dipyridamole are effective in reducing the risk of recurrence after a stroke. Importantly, the risk of recurrence is highest immediately after the index event while antiplatelets cause bleeding. Aims and/or hypothesis: The ‘Triple Antiplatelets for Reducing Dependency after Ischaemic Stroke’ (TARDIS) trial is testing whether short-term intensive antiplatelet therapy is safe and effective in reducing the early risk of recurrence as compared with standard guideline-based therapy. Design: TARDIS is an international multi-center prospective randomized open-label blinded–end-point trial, with funding from the UK Health Technology Assessment program. Patients with acute ischemic stroke or transient ischemic attack are randomized within 48 h to intensive/triple antiplatelet therapy or guideline antiplatelets taken for one-month. Patients or relatives give written informed (proxy) consent and all sites have research ethics approval. Analyses will be done by intention-to-treat. Study Outcome: The primary outcome is shift in stroke recurrent events and their severity, assessed using the modified Rankin Scale, at three-months. Discussion: This paper and attachment describe the trial’s statistical analysis plan, as developed from the protocol during recruitment and prior to unblinding of data. The statistical analysis plan contains design and methods for analyses, and unpopulated tables and figures for the primary and baseline publications. The data from the trial will provide the first large-scale randomized evidence for the use of intensive antiplatelet therapy for preventing recurrence after acute stroke and transient ischemic attack

Short email with attachment versus long email without attachment when contacting authors to request unpublished data for a systematic review: a nested randomised trial

Objective Systematic reviews often rely on the acquisition of unpublished analyses or data. We carried out a nested randomised trial comparing two different approaches for contacting authors to request additional data for a systematic review. Participants Participants were authors of published reports of prevention or treatment trials in stroke in which there was central adjudication of events. A primary and secondary research active author were selected as contacts for each trial. Interventions Authors were randomised to be sent either a short email with a protocol of the systematic review attached (‘Short’) or a longer email that contained detailed information and without the protocol attached (‘Long’). A maximum of two emails were sent to each author to obtain a response. The unit of analysis was trial, accounting for clustering by author. Primary and secondary outcome measures The primary outcome was whether a response was received from authors. Secondary outcomes included time to response, number of reminders needed before a response was received and whether authors agreed to collaborate. Results 88 trials with 76 primary authors were identified in the systematic review, and of these, 36 authors were randomised to Short (trials=45) and 40 to Long (trials=43). Responses were received for 69 trials. There was no evidence of a difference in response rate between trial arms (Short vs Long, OR 1.10, 95%CI 0.36 to 3.33). There was no evidence of a difference in time to response between trial arms (Short vs Long, HR 0.91, 95%CI 0.55 to 1.51). In total, 27% of authors responded within a day and 22% of authors never responded. Conclusions There was no evidence to suggest that email format had an impact on the number of responses received when acquiring data for a systematic review involving stroke trials or the time taken to receive these responses

Reprint: Good laboratory practice: preventing introduction of bias at the bench

As a research community, we have failed to show that drugs, which show substantial efficacy in animal models of cerebral ischemia, can also improve outcome in human stroke. Accumulating evidence suggests this may be due, at least in part, to problems in the design, conduct, and reporting of animal experiments which create a systematic bias resulting in the overstatement of neuroprotective efficacy. Here, we set out a series of measures to reduce bias in the design, conduct and reporting of animal experiments modeling human stroke

Reprint: Good laboratory practice: preventing introduction of bias at the bench

As a research community, we have failed to show that drugs, which show substantial efficacy in animal models of cerebral ischemia, can also improve outcome in human stroke. Accumulating evidence suggests this may be due, at least in part, to problems in the design, conduct, and reporting of animal experiments which create a systematic bias resulting in the overstatement of neuroprotective efficacy. Here, we set out a series of measures to reduce bias in the design, conduct and reporting of animal experiments modeling human stroke.</p

Protocol for a prospective collaborative systematic review and meta-analysis of individual patient data from randomised controlled trials of vasoactive drugs in acute stroke: the Blood pressure in Acute Stroke Collaboration, stage-3 (BASC-3)

Rationale Despite several large clinical trials assessing blood pressure lowering in acute stroke, equipoise remains, particularly for ischaemic stroke. The ‘Blood pressure in Acute Stroke Collaboration’ (BASC) commenced in the mid 1990s focusing on systematic reviews and meta-analysis of blood pressure lowering in acute stroke. From the start, BASC planned to assess safety and efficacy of blood pressure lowering in acute stroke using individual patient data. Aims To determine the optimal management of blood pressure in patients with acute stroke, encompassing both intracerebral haemorrhage and ischaemic stroke. Secondary aims are to assess which clinical and therapeutic factors may alter the optimal management of high blood pressure in patients with acute stroke and to assess the effect of vasoactive treatments on haemodynamic variables. Methods and design Individual patient data from randomised controlled trials of blood pressure management in participants with ischaemic stroke and/or intracerebral haemorrhage enrolled during the ultra-acute (pre-hospital), hyper-acute (<6 hours), acute (<48 hours) and sub-acute (<168 hours) phases of stroke. Study outcomes The primary effect variable will be functional outcome defined by the ordinal distribution of the modified Rankin Scale; analyses will also be carried out in prespecified subgroups to assess the modifying effects of stroke-related and pre-stroke patient characteristics. Key secondary variables will include clinical, haemodynamic and neuroradiological variables; safety variables will comprise death and serious adverse events. Discussion Study questions will be addressed in stages, according to the protocol, before integrating these into a final overreaching analysis. We invite eligible trials to join the collaboration

Nitric oxide for the prevention and treatment of viral, bacterial, protozoal and fungal infections.

Although the antimicrobial potential of nitric oxide (NO) is widely published, it is little used clinically. NO is a key signalling molecule modulating vascular, neuronal, inflammatory and immune responses. Endogenous antimicrobial activity is largely mediated by high local NO concentrations produced by cellular inducible nitric oxide synthase, and by derivative reactive nitrogen oxide species including peroxynitrite and S-nitrosothiols. NO may be taken as dietary substrate (inorganic nitrate, L-arginine), and therapeutically as gaseous NO, and transdermal, sublingual, oral, intranasal and intravenous nitrite or nitrate. Numerous preclinical studies have demonstrated that NO has generic static and cidal activities against viruses (including β-coronaviruses such as SARS-CoV-2), bacteria, protozoa and fungi/yeasts  in vitro. Therapeutic effects have been seen in animal models  in vivo, and phase II trials have demonstrated that NO donors can reduce microbial infection. Nevertheless, excess NO, as occurs in septic shock, is associated with increased morbidity and mortality. In view of the dose-dependent positive and negative effects of NO, safety and efficacy trials of NO and its donors are needed for assessing their role in the prevention and treatment of infections. Trials should test dietary inorganic nitrate for pre- or post-exposure prophylaxis and gaseous NO or oral, topical or intravenous nitrite and nitrate for treatment of mild-to-severe infections, including due to SARS-CoV-2 (COVID-19). This review summarises the evidence base from  in vitro, in vivo and early phase clinical studies of NO activity in viral, bacterial, protozoal and fungal infections

Nitric oxide for the prevention and treatment of viral, bacterial, protozoal and fungal infections

Although the antimicrobial potential of nitric oxide (NO) is widely published, it is little used clinically. NO is a key signalling molecule modulating vascular, neuronal, inflammatory and immune responses. Endogenous antimicrobial activity is largely mediated by high local NO concentrations produced by cellular inducible nitric oxide synthase, and by derivative reactive nitrogen oxide species including peroxynitrite and S-nitrosothiols. NO may be taken as dietary substrate (inorganic nitrate, L-arginine), and therapeutically as gaseous NO, and transdermal, sublingual, oral, intranasal and intravenous nitrite or nitrate. Numerous preclinical studies have demonstrated that NO has generic static and cidal activities against viruses (including β-coronaviruses such as SARS-CoV-2), bacteria, protozoa and fungi/yeasts in vitro. Therapeutic effects have been seen in animal models in vivo, and phase II trials have demonstrated that NO donors can reduce microbial infection. Nevertheless, excess NO, as occurs in septic shock, is associated with increased morbidity and mortality. In view of the dose-dependent positive and negative effects of NO, safety and efficacy trials of NO and its donors are needed for assessing their role in the prevention and treatment of infections. Trials should test dietary inorganic nitrate for pre- or post-exposure prophylaxis and gaseous NO or oral, topical or intravenous nitrite and nitrate for treatment of mild-to-severe infections, including due to SARS-CoV-2 (COVID-19). This review summarises the evidence base from in vitro, in vivo and early phase clinical studies of NO activity in viral, bacterial, protozoal and fungal infections

Prehospital transdermal glyceryl trinitrate in patients with ultra-acute presumed stroke (RIGHT-2): an ambulance-based, randomised, sham-controlled, blinded, phase 3 trial

BACKGROUND:High blood pressure is common in acute stroke and is a predictor of poor outcome; however, large trials of lowering blood pressure have given variable results, and the management of high blood pressure in ultra-acute stroke remains unclear. We investigated whether transdermal glyceryl trinitrate (GTN; also known as nitroglycerin), a nitric oxide donor, might improve outcome when administered very early after stroke onset. METHODS:We did a multicentre, paramedic-delivered, ambulance-based, prospective, randomised, sham-controlled, blinded-endpoint, phase 3 trial in adults with presumed stroke within 4 h of onset, face-arm-speech-time score of 2 or 3, and systolic blood pressure 120 mm Hg or higher. Participants were randomly assigned (1:1) to receive transdermal GTN (5 mg once daily for 4 days; the GTN group) or a similar sham dressing (the sham group) in UK-based ambulances by paramedics, with treatment continued in hospital. Paramedics were unmasked to treatment, whereas participants were masked. The primary outcome was the 7-level modified Rankin Scale (mRS; a measure of functional outcome) at 90 days, assessed by central telephone follow-up with masking to treatment. Analysis was hierarchical, first in participants with a confirmed stroke or transient ischaemic attack (cohort 1), and then in all participants who were randomly assigned (intention to treat, cohort 2) according to the statistical analysis plan. This trial is registered with ISRCTN, number ISRCTN26986053. FINDINGS:Between Oct 22, 2015, and May 23, 2018, 516 paramedics from eight UK ambulance services recruited 1149 participants (n=568 in the GTN group, n=581 in the sham group). The median time to randomisation was 71 min (IQR 45-116). 597 (52%) patients had ischaemic stroke, 145 (13%) had intracerebral haemorrhage, 109 (9%) had transient ischaemic attack, and 297 (26%) had a non-stroke mimic at the final diagnosis of the index event. In the GTN group, participants' systolic blood pressure was lowered by 5·8 mm Hg compared with the sham group (p<0·0001), and diastolic blood pressure was lowered by 2·6 mm Hg (p=0·0026) at hospital admission. We found no difference in mRS between the groups in participants with a final diagnosis of stroke or transient ischaemic stroke (cohort 1): 3 (IQR 2-5; n=420) in the GTN group versus 3 (2-5; n=408) in the sham group, adjusted common odds ratio for poor outcome 1·25 (95% CI 0·97-1·60; p=0·083); we also found no difference in mRS between all patients (cohort 2: 3 [2-5]; n=544, in the GTN group vs 3 [2-5]; n=558, in the sham group; 1·04 [0·84-1·29]; p=0·69). We found no difference in secondary outcomes, death (treatment-related deaths: 36 in the GTN group vs 23 in the sham group [p=0·091]), or serious adverse events (188 in the GTN group vs 170 in the sham group [p=0·16]) between treatment groups. INTERPRETATION:Prehospital treatment with transdermal GTN does not seem to improve functional outcome in patients with presumed stroke. It is feasible for UK paramedics to obtain consent and treat patients with stroke in the ultra-acute prehospital setting. FUNDING:British Heart Foundation