Prehospital transdermal glyceryl trinitrate in patients with ultra-acute presumed stroke (RIGHT-2): effects on outcomes at day 365 in a randomised, sham-controlled, blinded, phase III, superiority ambulance-based trial

Background

The Rapid Intervention with Glyceryl Trinitrate in Hypertensive Stroke Trial-2 (RIGHT-2) reported no overall treatment difference between glyceryl trinitrate (GTN) and sham at day 90. Here we assess participants' outcomes 1 year after randomisation.

Methods

RIGHT-2 was an ambulance-based prospective randomised controlled trial where patients with presumed stroke and systolic blood pressure (BP) of >120 mm Hg received either GTN (5 mg/day) or sham patch. Centralised blinded telephone follow-up was performed at days 90 (primary endpoint) and 365 (secondary endpoint). The lead outcome was dependency assessed with the modified Rankin Scale (mRS).

Results

1149 patients were recruited to RIGHT-2 between October 2015 and May 2018, and 1097 (95.5%) had outcome data recorded at day 365. At baseline, the patients were; female (48%), had a mean age of 73 (15) years, BP of 162 (25)/92 (18) mm Hg, onset to randomisation of 70 (45-115) min, diagnosis of ischaemic stroke (52%), intracerebral haemorrhage (ICH) (13%), transient ischaemic attack (TIA) (9%) and mimics (26%). There was no effect of GTN on mRS score at day 365 in participants with confirmed stroke/TIA (adjusted common odds ratio (acOR) 1.10, 95% CI 0.86 to 1.42) or in all patients. In patients randomised to GTN, mRS at day 365 tended to be worse in those with ICH (acOR 1.65, 95% CI 0.84 to 3.25) and better in those with a mimic diagnosis (acOR 0.53, 95% CI 0.33 to 0.84).

Conclusion

At 1 year post randomisation, dependency did not differ between GTN and sham treatment in either the target population or overall. In prespecified subgroup analyses, GTN was associated with reduced dependency in participants with a final diagnosis of mimic and a non-significant worse outcome in participants with ICH.

Trial registration number

ISRCTN26986053.

Morning report: how to do it

Morning report is an important clinical learning activity in many neurological institutions. A long experience of these meetings allows identification of several components to enhance its success. Meetings are best if brief (one or two cases) and held regularly, preferably daily and early in the working day, with full in-person team engagement. A senior clinician should lead the meeting and commit to a single interpretation, without fear of being wrong. Although the environment is relaxed (refreshments typically provided), it is a working meeting and with the essential focus on the patient rather than the learners. The rich learning experience is greatly enhanced by a subsequent confidential email summary and interpretation of the case(s) sent to all participants.

Principles of precision medicine in stroke

The era of precision medicine has arrived and conveys tremendous potential, particularly for stroke neurology. The diagnosis of stroke, its underlying aetiology, theranostic strategies, recurrence risk and path to recovery are populated by a series of highly individualised questions. Moreover, the phenotypic complexity of a clinical diagnosis of stroke makes a simple genetic risk assessment only partially informative on an individual basis. The guiding principles of precision medicine in stroke underscore the need to identify, value, organise and analyse the multitude of variables obtained from each individual to generate a precise approach to optimise cerebrovascular health. Existing data may be leveraged with novel technologies, informatics and practical clinical paradigms to apply these principles in stroke and realise the promise of precision medicine. Importantly, precision medicine in stroke will only be realised once efforts to collect, value and synthesise the wealth of data collected in clinical trials and routine care starts. Stroke theranostics, the ultimate vision of synchronising tailored therapeutic strategies based on specific diagnostic data, demand cerebrovascular expertise on big data approaches to clinically relevant paradigms. This review considers such challenges and delineates the principles on a roadmap for rational application of precision medicine to stroke and cerebrovascular health.

Enhancing cerebral perfusion with external counterpulsation after ischaemic stroke: how long does it last?

OBJECTIVE

External counterpulsation (ECP) is a non-invasive method used to augment cerebral perfusion in ischaemic stroke. We aimed to investigate time-course effects on blood pressure elevation and cerebral blood flow augmentation induced by ECP in ischaemic stroke.

METHODS

Patients with acute unilateral ischaemic stroke and large artery occlusive disease were recruited to receive 35 daily 1 h ECP treatment sessions. Serial transcranial Doppler monitoring of bilateral middle cerebral arteries was performed on days 3, 5, 7, 10, 14, 21, 28 and 35 after stroke onset. Flow velocity changes before, during and after ECP and continuous beat-to-beat blood pressure data were recorded. The cerebral augmentation index (CAI) is the increase in the percentage of the middle cerebral artery mean flow velocity during ECP compared with baseline.

RESULTS

The CAI in patients with stroke was significantly higher on the ipsilateral side and on the contralateral side on day 3 (ipsilateral CAI, 9.3%; contralateral CAI, 7.2%), day 5 (7.0%; 6.7%), day 7 (6.8%; 6.0%), day 10 (6.0%; 5.1%), day 14 (4.7%; 2.6%) and day 21 (4.1%; 2.2%) after stroke onset than that in controls (-2.0%) (all p<0.05). There was a significant trend of decreasing CAI on the ipsilateral and contralateral sides over time after a stroke. Differences in the percentage increase in the mean blood pressure did not change significantly over time in patients with stroke.

CONCLUSIONS

Blood pressure elevation persists throughout ECP treatment, which consists of 35 sessions. However, cerebral blood flow augmentation may last at least 3 weeks and then appears to return to baseline 1 month after acute stroke onset.

Interictal cerebral and systemic endothelial dysfunction in patients with migraine: a case-control study

BACKGROUND

Although systemic endothelial function is unimpaired in migraine, it is unknown whether cerebral endothelial function impairment exists in migraineurs.

MATERIALS AND METHODS

We conducted a prospective study to assess endothelial function in migraineurs (n=45) and healthy volunteers (n=44). Cerebral endothelial function was assessed by Breath Holding Index (BHI) on transcranial Doppler in bilateral middle cerebral artery (MCA at 30-60 mm), posterior cerebral artery (PCA at 60-80 mm) and basilar artery (BA at 80-120 mm) using bilateral monitoring probes fixed on headband. Brachial artery flow-mediated dilation (FMD) was used as measure of systemic endothelial function.

RESULTS

There was no difference in baseline mean velocities of MCA, PCA, BA among migraineurs and controls. Mean BHI was significantly lower in PCA (p<0.001) and BA (p<0.001) in patients with migraine with no difference in MCA (p=0.909, 0.450). Cerebral endothelial dysfunction (BHI<1.15) was present in 62.2% of migraineurs in the right PCA (p<0.001), 57.8% in left PCA (p<0.001) and 77.8% in BA (BHI <0.83, p<0.001). There was no difference in BHI among migraineurs without and with aura (n=15). Cerebral and systemic endothelial function had no correlation in migraineurs. Increasing BMI was identified as a predictor of impaired BHI in the BA in migraineurs (p=0.020). Age, sex, presence of aura, lateralisation of headache, headache frequency, time to last attack and impaired FMD were not associated with impaired PCA and BA BHI in migraineurs.

CONCLUSIONS

Migraineurs may have isolated cerebral endothelial dysfunction restricted to the posterior circulation in the absence of systemic endothelial dysfunction.

The pathophysiology and treatment of delayed cerebral ischaemia following subarachnoid haemorrhage

Cerebral vasospasm has traditionally been regarded as an important cause of delayed cerebral ischaemia (DCI) which occurs after aneurysmal subarachnoid haemorrhage, and often leads to cerebral infarction and poor neurological outcome. However, data from recent studies argue against a pure focus on vasospasm as the cause of delayed ischaemic complications. Findings that marked reduction in the incidence of vasospasm does not translate to a reduction in DCI, or better outcomes has intensified research into other possible mechanisms which may promote ischaemic complications. Early brain injury and cell death, blood-brain barrier disruption and initiation of an inflammatory cascade, microvascular spasm, microthrombosis, cortical spreading depolarisations and failure of cerebral autoregulation, have all been implicated in the pathophysiology of DCI. This review summarises the current knowledge about the mechanisms underlying the development of DCI. Furthermore, it aims to describe and categorise the known pharmacological treatment options with respect to the presumed mechanism of action and its role in DCI.

Reduced grey matter perfusion without volume loss in early relapsing-remitting multiple sclerosis

BACKGROUND

Grey matter (GM) pathology in multiple sclerosis (MS) is associated with progressive long-term disability. Detection of GM abnormalities in early MS may therefore be valuable in understanding and predicting the long-term course. However, structural MRI measures such as volume loss have shown only modest abnormalities in early relapsing-remitting MS (RRMS). We therefore investigated for evidence of abnormality in GM perfusion, consistent with metabolic dysfunction, in early RRMS.

METHODS

25 RRMS patients with ≤5 years disease duration and 25 age-matched healthy controls underwent 3 Tesla MRI with a pseudo-continuous arterial spin labelling sequence to quantify GM perfusion and a volumetric T1-weighted sequence to measure GM volume. Neurological status was assessed in patients and neuropsychological evaluation undertaken in all subjects. Voxel-based analysis was used to compare regional GM perfusion and volume measures in patients and controls.

RESULTS

There was reduced global GM perfusion in patients versus controls (50.6±5.8 mL/100 g/min vs 54.4±7.6 mL/100 g/min, p=0.04). Voxel-based analysis revealed extensive regions of decreased cortical and deep GM perfusion in MS subjects. Reduced perfusion was associated with impaired memory scores. There was no reduction in global or regional analysis of GM volume in patients versus controls.

CONCLUSIONS

The decrease in GM perfusion in the absence of volume loss is consistent with neuronal metabolic dysfunction in early RRMS. Future studies in larger cohorts and longitudinal follow-up are needed to investigate the functional and prognostic significance of the early GM perfusion deficits observed.

Impaired perfusion modifies the relationship between blood pressure and stroke risk in major cerebral artery disease

OBJECTIVE

Blood pressure (BP) lowering may increase stroke risk in patients with symptomatic major cerebral artery disease and impaired perfusion. To investigate the relationships among BP, impaired perfusion and stroke risk.

METHODS

We retrospectively analysed data from 130 non-disabled, medically treated patients with either symptomatic extracranial carotid occlusion or intracranial stenosis or occlusion of the carotid artery or middle cerebral arteries. All patients had baseline haemodynamic measurements with (15)O-gas positron emission tomography and were followed for 2 years or until stroke recurrence or death.

RESULTS

There was a negative linear relationship between systolic BP (SBP) and risk of stroke in the territory of the diseased artery. The 2-year incidence of ischaemic stroke in the territory in patients with normal SBP (<130 mm Hg, 5/32 patients) was significantly higher than in patients with high SBP (2/98, p<0.005). Multivariate analysis revealed that normal SBP and impaired perfusion were independently associated with increased risk of stroke in the previously affected territory, while risk of stroke elsewhere was positively correlated with SBP. Overall, high total stroke risk was observed at lower BP in patients with impaired perfusion and at higher BPs in patients without (interaction, p<0.01). Overall, the relationship between SBP and total stroke recurrence was J-shaped.

CONCLUSIONS

Impaired perfusion modified the relationship between blood pressure and stroke risk, although this study had limitations including the retrospective analysis, the potentially biased sample, the small number of critical events and the fact that BP was measured only as a snapshot in clinic.