Statistical analysis plan for the 'Rapid Intervention with Glyceryl trinitrate in Hypertensive stroke Trial-2 (RIGHT-2)'

Pre-hospital transdermal glyceryl trinitrate for transient ischaemic attack: Data from the RIGHT-2 trial

BACKGROUND AND PURPOSE

Ambulance trials assessing interventions in suspected stroke patients will recruit patients with currently active symptoms that will resolve into transient ischaemic attack (TIA). The safety and efficacy of glyceryl trinitrate (GTN) in the pre-specified subgroup of patients with TIA in the Rapid Intervention with Glyceryl Trinitrate in Hypertensive Stroke Trial 2 (RIGHT-2) was assessed.

METHODS

RIGHT-2 was a pre-hospital-initiated multicentre randomized sham-controlled blinded-endpoint trial that randomized patients with presumed ultra-acute stroke within 4 h of symptom onset to transdermal GTN or sham. Final diagnosis was determined by site investigators. The primary outcome was a shift in modified Rankin Scale (mRS) scores at 90 days analysed using ordinal logistic regression reported as adjusted common odds ratio with 95% confidence intervals (CIs). Secondary outcomes included death or dependence (mRS >2).

RESULTS

In all, 109 of 1149 (9.5%) patients had a final diagnosis of TIA (GTN 57, sham 52) with mean age 73 (SD 13) years, 19 (17.4%) had pre-morbid mRS >2, and onset to randomization was 80 min (interquartile range 49, 105). GTN lowered blood pressure by 7.4/5.2 mmHg compared with sham by hospital arrival. At day 90, GTN had no effect on shift in mRS scores (common odds ratio for increased dependence 1.47, 95% CI 0.70-3.11) but was associated with increased death or dependence (mRS >2): GTN 29 (51.8%) versus sham 23 (46.9%), odds ratio 3.86 (95% CI 1.09-13.59).

CONCLUSIONS

Pre-hospital ultra-acute transdermal GTN did not improve overall functional outcome in patients with investigator-diagnosed TIA compared with sham treatment.

Prehospital transdermal glyceryl trinitrate for ultra-acute ischaemic stroke: data from the RIGHT-2 randomised sham-controlled ambulance trial

BACKGROUND

The effect of transdermal glyceryl trinitrate (GTN, a nitrovasodilator) on clinical outcome when administered before hospital admission in suspected stroke patients is unclear. Here, we assess the safety and efficacy of GTN in the prespecified subgroup of patients who had an ischaemic stroke within the Rapid Intervention with Glyceryl trinitrate in Hypertensive stroke Trial-2 (RIGHT-2).

METHODS

RIGHT-2 was an ambulance-based multicentre sham-controlled blinded-endpoint study with patients randomised within 4 hours of onset. The primary outcome was a shift in scores on the modified Rankin scale (mRS) at day 90. Secondary outcomes included death; a global analysis (Wei-Lachin test) containing Barthel Index, EuroQol-5D, mRS, telephone interview for cognitive status-modified and Zung depression scale; and neuroimaging-determined 'brain frailty' markers. Data were reported as n (%), mean (SD), median [IQR], adjusted common OR (acOR), mean difference or Mann-Whitney difference (MWD) with 95% CI.

RESULTS

597 of 1149 (52%) patients had a final diagnosis of ischaemic stroke; age 75 (12) years, premorbid mRS>2 107 (18%), Glasgow Coma Scale 14 (2) and time from onset to randomisation 67 [45, 108] min. Neuroimaging 'brain frailty' was common: median score 2 [2, 3] (range 0-3). At day 90, GTN did not influence the primary outcome (acOR for increased disability 1.15, 95% CI 0.85 to 1.54), death or global analysis (MWD 0.00, 95% CI -0.10 to 0.09). In subgroup analyses, there were non-significant interactions suggesting GTN may be associated with more death and dependency in participants randomised within 1 hour of symptom onset and in those with more severe stroke.

CONCLUSIONS

In patients who had an ischaemic stroke, ultra-acute administration of transdermal GTN in the ambulance did not improve clinical outcomes in a population with more clinical and radiological frailty than seen in previous in-hospital trials.

Challenges and Experiences in Multicenter Prehospital Stroke Research: Narrative Data from the Rapid Intervention with Glyceryl Trinitrate in Hypertensive Stroke Trial-2 (RIGHT-2)

BACKGROUND

Ambulance services are increasingly research active and the Rapid Intervention with Glyceryl trinitrate in Hypertensive stroke Trial-2 (RIGHT-2) is the largest United Kingdom (UK) ambulance-based randomized controlled trial in stroke. We explore the complexities and challenges encountered during RIGHT-2.

METHODS

Five hundred and sixteen of 1487 paramedics from eight UK ambulance services serving 54 comprehensive or primary stroke care centers screened and consented 1149 patients presenting within 4 h of FAST-positive stroke and with systolic blood pressure >120 mmHg; participants were randomized to treatment with transdermal glyceryl trinitrate versus sham patch in the ambulance.

KEY FINDINGS

Working with multiple ambulance services demanded flexibility in the trial protocol to overcome variation in operating procedures to ensure deliverability. Many paramedics are novice researchers, and research concepts and practices are emerging including consent strategies in emergency stroke care. Regional variation in hospital participation and hours/days of operation presented paramedics with additional considerations prior to patient recruitment. The working hours of hospital research staff often do not reflect the 24/7 nature of ambulance work, which challenged deliverability until trial processes became fully embedded. Management of investigational medicinal product between ambulance stations, in-transit when on ambulance vehicles and on handover at hospital, necessitated an in-depth review to maintain accountability.

CONCLUSION

RIGHT-2 demonstrated that although there are significant practical challenges to conducting multicenter ambulance-based research in a time-dependent environment, careful planning and management facilitated delivery. Lessons learned here will help inform the design and conduct of future ambulance-based trials.

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.

Time intervals and distances travelled for prehospital ambulance stroke care: data from the randomised-controlled ambulance-based Rapid Intervention with Glyceryl trinitrate in Hypertensive stroke Trial-2 (RIGHT-2)

OBJECTIVES

Ambulances offer the first opportunity to evaluate hyperacute stroke treatments. In this study, we investigated the conduct of a hyperacute stroke study in the ambulance-based setting with a particular focus on timings and logistics of trial delivery.

DESIGN

Multicentre prospective, single-blind, parallel group randomised controlled trial.

SETTING

Eight National Health Service ambulance services in England and Wales; 54 acute stroke centres.

PARTICIPANTS

Paramedics enrolled 1149 patients assessed as likely to have a stroke, with Face, Arm, Speech and Time score (2 or 3), within 4 hours of symptom onset and systolic blood pressure >120 mm Hg.

INTERVENTIONS

Paramedics administered randomly assigned active transdermal glyceryl trinitrate or sham.

PRIMARY AND SECONDARY OUTCOMES

Modified Rankin scale at day 90. This paper focuses on response time intervals, distances travelled and baseline characteristics of patients, compared between ambulance services.

RESULTS

Paramedics enrolled 1149 patients between September 2015 and May 2018.

FINAL DIAGNOSIS

intracerebral haemorrhage 13%, ischaemic stroke 52%, transient ischaemic attack 9% and mimic 26%. Timings (min) were (median (25-75 centile)): onset to emergency call 19 (5-64); onset to randomisation 71 (45-116); total time at scene 33 (26-46); depart scene to hospital 15 (10-23); randomisation to hospital 24 (16-34) and onset to hospital 97 (71-141). Ambulances travelled (km) 10 (4-19) from scene to hospital. Timings and distances differed between ambulance service, for example, onset to randomisation (fastest 53 min, slowest 77 min; p<0.001), distance from scene to hospital (least 4 km, most 20 km; p<0.001).

CONCLUSION

We completed a large prehospital stroke trial involving a simple-to-administer intervention across multiple ambulance services. The time from onset to randomisation and modest distances travelled support the applicability of future large-scale paramedic-delivered ambulance-based stroke trials in urban and rural locations.

TRIAL REGISTRATION NUMBER

ISRCTN26986053.

Pre-hospital transdermal glyceryl trinitrate in patients with stroke mimics: data from the RIGHT-2 randomised-controlled ambulance trial

BACKGROUND

Prehospital stroke trials will inevitably recruit patients with non-stroke conditions, so called stroke mimics. We undertook a pre-specified analysis to determine outcomes in patients with mimics in the second Rapid Intervention with Glyceryl trinitrate in Hypertensive stroke Trial (RIGHT-2).

METHODS

RIGHT-2 was a prospective, multicentre, paramedic-delivered, ambulance-based, sham-controlled, participant-and outcome-blinded, randomised-controlled trial of transdermal glyceryl trinitrate (GTN) in adults with ultra-acute presumed stroke in the UK. Final diagnosis (intracerebral haemorrhage, ischaemic stroke, transient ischaemic attack, mimic) was determined by the hospital investigator. This pre-specified subgroup analysis assessed the safety and efficacy of transdermal GTN (5 mg daily for 4 days) versus sham patch among stroke mimic patients. The primary outcome was the 7-level modified Rankin Scale (mRS) at 90 days.

RESULTS

Among 1149 participants in RIGHT-2, 297 (26%) had a final diagnosis of mimic (GTN 134, sham 163). The mimic group were younger, mean age 67 (SD: 18) vs 75 (SD: 13) years, had a longer interval from symptom onset to randomisation, median 75 [95% CI: 47,126] vs 70 [95% CI:45,108] minutes, less atrial fibrillation and a lower systolic blood pressure and Face-Arm-Speech-Time tool score than the stroke group. The three most common mimic diagnoses were seizure (17%), migraine or primary headache disorder (17%) and functional disorders (14%). At 90 days, the GTN group had a better mRS score as compared to the sham group (adjusted common odds ratio 0.54; 95% confidence intervals 0.34, 0.85; p = 0.008), a difference that persisted at 365 days. There was no difference in the proportion of patients who died in hospital, were discharged to a residential care facility, or suffered a serious adverse event.

CONCLUSIONS

One-quarter of patients suspected by paramedics to have an ultra-acute stroke were subsequently diagnosed with a non-stroke condition. GTN was associated with unexplained improved functional outcome observed at 90 days and one year, a finding that may represent an undetected baseline imbalance, chance, or real efficacy. GTN was not associated with harm.

TRIAL REGISTRATION

This trial is registered with International Standard Randomised Controlled Trials Number ISRCTN 26986053 .

Prehospital Transdermal Glyceryl Trinitrate for Ultra-Acute Intracerebral Hemorrhage: Data From the RIGHT-2 Trial

Supplemental Digital Content is available in the text.

Pilot trials suggest that glyceryl trinitrate (GTN; nitroglycerin) may improve outcome when administered early after stroke onset.

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.

Baseline characteristics of the 1149 patients recruited into the Rapid Intervention with Glyceryl trinitrate in Hypertensive stroke Trial-2 (RIGHT-2) randomized controlled trial

Background

High blood pressure is common in acute stroke and associated with a worse functional outcome. Glyceryl trinitrate, a nitric oxide donor, lowers blood pressure in acute stroke and may improve outcome.

Aims

Rapid Intervention with Glyceryl trinitrate in Hypertensive stroke Trial-2 (RIGHT-2) tested the feasibility of performing a UK multicenter ambulance-based stroke trial, and the safety and efficacy of glyceryl trinitrate when administered by paramedics before hospital admission.

Methods

Paramedic-led ambulance-based multicenter prospective randomized single-blind blinded-endpoint parallel-group controlled trial of transdermal glyceryl trinitrate (given for four days) versus sham in patients with ultra-acute (<4 h) presumed stroke. Data are number (%), median (interquartile range) or mean (standard deviation).

Results

Recruitment ran from October 2015 to 31 May 2018. A total 1149 patients were recruited from eight UK ambulance services and taken to 54 acute hospitals. Baseline characteristics include: mean age 73 (15) years; female 555 (48%); median time from stroke to randomization 70 (45, 115) min; face-arm-speech scale score 2.6 (0.5); and blood pressure 162 (25)/92 (18) mmHg. The final diagnosis was ischemic stroke 52%, hemorrhagic stroke 13%, Transient Ischemic Attack (TIA) 9%, and mimic 25%. The main trial results will be presented in quarter 4 2018. The results will also be included in updated Cochrane systematic reviews, and individual patient data meta-analyses of all relevant randomized controlled trials.

Conclusion

It was feasible to perform a multicenter ambulance-based ultra-acute stroke trial in the UK and to treat with glyceryl trinitrate versus sham. The relatively unselected cohort of stroke patients is broadly representative of those admitted to hospital in the UK.

Trial registration

ISRCTN26986053.