Biomarkers predictive of atrial fibrillation in patients with cryptogenic stroke. Insights from the Nordic Atrial Fibrillation and Stroke (NOR-FIB) study.

BACKGROUND AND PURPOSE: There are currently no biomarkers to select cryptogenic stroke (CS) patients for monitoring with insertable cardiac monitors (ICMs), the most effective tool for diagnosing atrial fibrillation (AF) in CS. The purpose of this study was to assess clinically available biomarkers as predictors of AF. METHODS: Eligible CS and cryptogenic transient ischaemic attack patients underwent 12-month monitoring with ICMs, clinical follow-up and biomarker sampling. Levels of cardiac and thromboembolic biomarkers, taken within 14 days from symptom onset, were compared between patients diagnosed with AF (n = 74) during monitoring and those without AF (n = 185). Receiver operating characteristic curves were created. Biomarkers reaching area under the receiver operating characteristic curve ≥ 0.7 were dichotomized by finding optimal cut-off values and were used in logistic regression establishing their predictive value for increased risk of AF in unadjusted and adjusted models. RESULTS: B-type natriuretic peptide (BNP), N-terminal pro-brain natriuretic peptide (NT-proBNP), creatine kinase, D-dimer and high-sensitivity cardiac troponin I and T were significantly higher in the AF than non-AF group. BNP and NT-proBNP reached the predefined area under the curve level, 0.755 and 0.725 respectively. Optimal cut-off values were 33.5 ng/l for BNP and 87 ng/l for NT-proBNP. Regression analysis showed that NT-proBNP was a predictor of AF in both unadjusted (odds ratio 7.72, 95% confidence interval 3.16-18.87) and age- and sex-adjusted models (odds ratio 4.82, 95% confidence interval 1.79-12.96). CONCLUSION: Several clinically established biomarkers were associated with AF. NT-proBNP performed best as AF predictor and could be used for selecting patients for long-term monitoring with ICMs.

Tenecteplase versus alteplase for the management of acute ischaemic stroke in Norway (NOR-TEST 2, part A): a phase 3, randomised, open-label, blinded endpoint, non-inferiority trial.

BACKGROUND: Tenecteplase is a modified tissue plasminogen activator with pharmacological and practical advantages over alteplase-which is currently the only approved thrombolytic drug for ischaemic stroke. The NOR-TEST trial showed that 0·4 mg/kg tenecteplase had an efficacy and safety profile similar to that of a standard dose (0·9 mg/kg) of alteplase, albeit in a patient population with a high prevalence of minor stroke. The aim of NOR-TEST 2 was to establish the non-inferiority of tenecteplase 0·4 mg/kg to alteplase 0·9 mg/kg for patients with moderate or severe ischaemic stroke. METHODS: This phase 3, randomised, open-label, blinded endpoint, non-inferiority trial was performed at 11 hospitals with stroke units in Norway. Patients with suspected acute ischaemic stroke with a National Institutes of Health Stroke Scale score of 6 or more who were eligible for thrombolysis and admitted within 4·5 h of symptom onset were consecutively included. Random assignment, done by a computer with a block size of 4 and with allocations placed into opaque envelopes to be opened consecutively, was 1:1 between intravenous tenecteplase (0·4 mg/kg) or standard dose alteplase (0·9 mg/kg). Doctors and nurses providing acute care were not masked to treatment, but primary outcome assessment at 3 months was masked. The primary outcome was favourable functional outcome defined as a modified Rankin Scale score of 0-1 at 3 months, assessed in the modified intention-to-treat analysis (excluding patients who did not qualify for thrombolysis after randomisation or who withdrew informed consent). The non-inferiority margin was 3%. This trial (NOR-TEST 2) is registered with EudraCT (number 2018-003090-95) and ClinicalTrials.gov (NCT03854500). The trial was stopped early for safety reasons and is designated part A for analysis. Part B is ongoing with a lower dose of tenecteplase (0·25 mg/kg). FINDINGS: Between Oct 28, 2019, and Sept 26, 2021, 216 patients were enrolled. Patient enrolment was stopped after a per-protocol safety review showed an imbalance in the rates of symptomatic intracranial haemorrhage between the treatment groups, which surpassed the prespecified criteria for stopping the trial. Of 204 patients entering the modified intention-to-treat analysis, 100 were randomly allocated tenecteplase and 104 were allocated alteplase. All patients were followed up within 14 days of the end of the 3-months' follow-up period. A favourable functional outcome was reported less frequently in patients receiving tenecteplase (31 [32%] of 96 patients) compared with alteplase (52 [51%] of 101 patients; unadjusted OR 0·45 [95% CI 0·25-0·80]; p=0·0064). Any intracranial haemorrhage was significantly more frequent with tenecteplase (21 [21%] of 100 patients) than with alteplase (seven [7%] of 104 patients; unadjusted OR 3·68 [95% CI 1·49-9·11]; p=0·0031). Mortality at 3 months was also significantly higher with tenecteplase (15 [16%] of 96 patients) than with alteplase (five [5%] of 101 patients; unadjusted OR 3·56 [95% CI 1·24-10·21]; p=0·013). Numerically more cases of symptomatic intracranial haemorrhage were reported with tenecteplase (six [6%] of 100 patients) than with alteplase (one [1%] of 104 patients; unadjusted OR 6·57 [95% CI 0·78-55·62]; p=0·061). INTERPRETATION: In this prematurely terminated study (terminated to fulfil the prespecified safety criteria), tenecteplase at a dose of 0·4 mg/kg yielded worse safety and functional outcomes compared with alteplase. Our study consequently could not show that 0·4 mg/kg tenecteplase is non-inferior to alteplase in moderate and severe ischaemic stroke. Future stroke trials should assess a lower dose of tenecteplase versus alteplase in patients with moderate or severe stroke. FUNDING: The Norwegian National Programme for Clinical Therapy Research.

Atrial fibrillation in cryptogenic stroke and transient ischaemic attack - The Nordic Atrial Fibrillation and Stroke (NOR-FIB) Study: Rationale and design.

PURPOSE: Paroxysmal atrial fibrillation is often suspected as a probable cause of cryptogenic stroke. Continuous long-term ECG monitoring using insertable cardiac monitors is a clinically effective technique to screen for atrial fibrillation and superior to conventional follow-up in cryptogenic stroke. However, more studies are needed to identify factors which can help selecting patients with the highest possibility of detecting atrial fibrillation with prolonged rhythm monitoring. The clinical relevance of short-term atrial fibrillation, the need for medical intervention and the evaluation as to whether intervention results in improved clinical outcomes should be assessed. METHOD: The Nordic Atrial Fibrillation and Stroke Study is an international, multicentre, prospective, observational trial evaluating the occurrence of occult atrial fibrillation in cryptogenic stroke and transient ischaemic attack. Patients with cryptogenic stroke or transient ischaemic attack from the Nordic countries are included and will have the Reveal LINQ® Insertable cardiac monitor system implanted for 12 months for atrial fibrillation detection. Biomarkers which can be used as predictors for atrial fibrillation and may identify patients, who could derive the most clinical benefit from the detection of atrial fibrillation by prolonged monitoring, are being studied. CONCLUSION: The primary endpoint is atrial fibrillation burden within 12 months of continuous rhythm monitoring. Secondary endpoints are atrial fibrillation burden within six months, levels of biomarkers predicting atrial fibrillation, CHA2DS2-VASc score, incidence of recurrent stroke or transient ischaemic attack, use of anticoagulation and antiarrhythmic drugs, and quality of life measurements. The clinical follow-up period is 12 months. The study started in 2017 and the completion is expected at the end of 2020.

Tenecteplase Versus Alteplase Between 3 and 4.5 Hours in Low National Institutes of Health Stroke Scale.

Background and Purpose- Thrombolysis with alteplase has beneficial effect on outcome and is safe within 4.5 hours. The present study compares the efficacy and safety of tenecteplase and alteplase in patients treated 3 to 4.5 hours after ischemic stroke. Methods- The data are from a prespecified substudy of patients included in The NOR-TEST (Norwegian Tenecteplase Stroke Trial), a randomized control trial comparing tenecteplase with alteplase. Results- The median admission National Institutes of Health Stroke Scale for this study population was 3 (interquartile range, 2-6). In the intention-to-treat analysis, 57% of patients that received tenecteplase and 53% of patients that received alteplase reached good functional outcome (modified Rankin Scale score of 0-1) at 3 months (odds ratio, 1.19; 95% CI, 0.68-2.10). The rates of intracranial hemorrhage in the first 48 hours were 5.7% in the tenecteplase group and 6.7% in the alteplase group (odds ratio, 0.84; 95% CI, 0.26-2.70). At 3 months, mortality was 5.7% and 4.5%, respectively. After excluding stroke mimics and patients with modified Rankin Scale score of >1 before stroke, the proportion of patients with good functional outcome was 61% in the tenecteplase group and 57% in the alteplase group (odds ratio, 1.24; 95% CI, 0.65-2.37). Conclusions- Tenecteplase is at least as effective as alteplase to achieve a good clinical outcome in patients with mild stroke treated between 3 and 4.5 hours after ischemic stroke. Clinical Trial Registration- URL: https://www.clinicaltrials.gov . Unique identifier: NCT01949948.

Tenecteplase versus alteplase for management of acute ischaemic stroke (NOR-TEST): a phase 3, randomised, open-label, blinded endpoint trial.

BACKGROUND: Tenecteplase is a newer thrombolytic agent with some pharmacological advantages over alteplase. Previous phase 2 trials of tenecteplase in acute ischaemic stroke have shown promising results. We aimed to investigate the safety and efficacy of tenecteplase versus alteplase in patients with acute stroke who were eligible for intravenous thrombolysis. METHODS: This phase 3, randomised, open-label, blinded endpoint, superiority trial was done in 13 stroke units in Norway. We enrolled adults with suspected acute ischaemic stroke who were eligible for thrombolysis and admitted within 4·5 h of symptom onset or within 4·5 h of awakening with symptoms, or who were eligible for bridging therapy before thrombectomy. Patients were randomly assigned (1:1) to receive intravenous tenecteplase 0·4 mg/kg (to a maximum of 40 mg) or alteplase 0·9 mg/kg (to a maximum of 90 mg), via a block randomisation schedule stratified by centre of inclusion. Patients were not informed of treatment allocation; treating physicians were aware of treatment allocation but those assessing the primary and secondary endpoints were not. The primary outcome was excellent functional outcome defined as modified Rankin Scale (mRS) score 0-1 at 3 months. The primary analysis was an unadjusted and non-stratified intention-to-treat analysis with last observation carried forward for imputation of missing data. This study is registered with ClinicalTrials.gov, number NCT01949948. FINDINGS: Between Sept 1, 2012, and Sept 30, 2016, 1107 patients met the inclusion criteria and seven patients were excluded because informed consent was withdrawn or eligibility for thrombolytic treatment was reconsidered. 1100 patients were randomly assigned to the tenecteplase (n=549) or alteplase (n=551) groups. The median age of participants was 77 years (IQR 64-79) and the median National Institutes of Health Stroke Scale score at baseline was 4 points (IQR 2-8). A final diagnosis other than ischaemic stroke or transient ischaemic attack was found in 99 (18%) patients in the tenecteplase group and 91 (17%) patients in the alteplase group. The primary outcome was achieved by 354 (64%) patients in the tenecteplase group and 345 (63%) patients in the alteplase group (odds ratio 1·08, 95% CI 0·84-1·38; p=0·52). By 3 months, 29 (5%) patients had died in the tenecteplase group compared with 26 (5%) in the alteplase group. The frequency of serious adverse events was similar between groups (145 [26%] in the tenecteplase group vs 141 [26%] in the alteplase group; p=0·74). INTERPRETATION: Tenecteplase was not superior to alteplase and showed a similar safety profile. Most patients enrolled in this study had mild stroke. Further trials are needed to establish the safety and efficacy in patients with severe stroke and whether tenecteplase is non-inferior to alteplase. FUNDING: Research Council of Norway.

A pragmatic approach to sonothrombolysis in acute ischaemic stroke: the Norwegian randomised controlled sonothrombolysis in acute stroke study (NOR-SASS).

BACKGROUND: Ultrasound accelerates thrombolysis with tPA (sonothrombolysis). Ultrasound in the absence of tPA also accelerates clot break-up (sonolysis). Adding intravenous gaseous microbubbles may potentiate the effect of ultrasound in both sonothrombolysis and sonolysis. The Norwegian Sonothrombolysis in Acute Stroke Study aims in a pragmatic approach to assess the effect and safety of contrast enhanced ultrasound treatment in unselected acute ischaemic stroke patients. METHODS/DESIGN: Acute ischaemic stroke patients ≥ 18 years, with or without visible arterial occlusion on computed tomography angiography (CTA) and treatable ≤ 4(½) hours after symptom onset, are included in NOR-SASS. NOR-SASS is superimposed on a separate trial randomising patients with acute ischemic stroke to either tenecteplase or alteplase (The Norwegian Tenecteplase Stroke Trial NOR-TEST). The NOR-SASS trial has two arms: 1) the thrombolysis-arms (NOR-SASS A and B) includes patients given intravenous thrombolysis (tenecteplase or alteplase), and 2) the no-thrombolysis-arm (NOR-SASS C) includes patients with contraindications to thrombolysis. First step randomisation of NOR-SASS A is embedded in NOR-TEST as a 1:1 randomisation to either tenecteplase or alteplase. Second step NOR-SASS randomisation is 1:1 to either contrast enhanced sonothrombolysis (CEST) or sham CEST. Randomisation in NOR-SASS B (routine alteplase group) is 1:1 to either CEST or sham CEST. Randomisation of NOR-SASS C is 1:1 to either contrast enhanced sonolysis (CES) or sham CES. Ultrasound is given for one hour using a 2-MHz pulsed-wave diagnostic ultrasound probe. Microbubble contrast (SonoVue®) is given as a continuous infusion for ~30 min. Recanalisation is assessed at 60 min after start of CEST/CES. Magnetic resonance imaging and angiography is performed after 24 h of stroke onset. Primary study endpoints are 1) major neurological improvement measured with NIHSS score at 24 h and 2) favourable functional outcome defined as mRS 0-1 at 90 days. DISCUSSION: NOR-SASS is the first randomised controlled trial designed to test the superiority of contrast enhanced ultrasound treatment given ≤ 4(½) hours after stroke onset in an unselected acute ischaemic stroke population eligible or not eligible for intravenous thrombolysis, with or without a defined arterial occlusion on CTA. If a positive effect and safety can be proven, contrast enhanced ultrasound treatment will be an option for all acute ischaemic stroke patients. EudraCT No 201200032341; www.clinicaltrials.gov NCT01949961.