Predictors of Atrial Fibrillation Development in Patients With Embolic Stroke of Undetermined Source: An Analysis of the RE-SPECT ESUS Trial.

BACKGROUND: A proportion of patients with embolic stroke of undetermined source have silent atrial fibrillation (AF) or develop AF after the initial evaluation. Better understanding of the risk for development of AF is critical to implement optimal monitoring strategies with the goal of preventing recurrent stroke attributable to underlying AF. The RE-SPECT ESUS trial (Randomized, Double-Blind Evaluation in Secondary Stroke Prevention Comparing the Efficacy and Safety of the Oral Thrombin Inhibitor Dabigatran Etexilate Versus Acetylsalicylic Acid in Patients With Embolic Stroke of Undetermined Source) provides an opportunity to assess predictors for developing AF and associated recurrent stroke. METHODS: RE-SPECT ESUS was a randomized, controlled trial (564 sites, 42 countries) assessing dabigatran versus aspirin for the prevention of recurrent stroke in patients with embolic stroke of undetermined source. Of 5390 patients enrolled and followed for a median of 19 months, 403 (7.5%) were found to develop AF reported as an adverse event or using cardiac monitoring per standard clinical care. Univariable and multivariable regression analyses were performed to define predictors of AF. RESULTS: In the multivariable model, older age (odds ratio for 10-year increase, 1.99 [95% CI, 1.78-2.23]; P<0.001), hypertension (odds ratio, 1.36 [95% CI, 1.03-1.79]; P=0.0304), diabetes (odds ratio, 0.74 [95% CI, 0.56-0.96]; P=0.022), and body mass index (odds ratio for 5-U increase, 1.29 [95% CI, 1.16-1.43]; P<0.001) were independent predictors of AF during the study. In a sensitivity analysis restricted to 1117 patients with baseline NT-proBNP (N-terminal prohormone of brain natriuretic peptide) measurements, only older age and higher NT-proBNP were significant independent predictors of AF. Performance of several published predictive models was assessed, including HAVOC (AF risk score based on hypertension, age ≥75 years, valvular heart disease, peripheral vascular disease, obesity, congestive heart failure, and coronary artery disease) and CHA2DS2-VASc (stroke risk score based on congestive heart failure, hypertension, age ≥75 years [doubled], diabetes, previous stroke, transient ischemic attack or thromboembolism [doubled], vascular disease, age 65 to 74 years, and sex category [female]) scores, and higher scores were associated with higher rates of developing AF. CONCLUSIONS: Besides age, the most important variable, several other factors, including hypertension, higher body mass index, and lack of diabetes, are independent predictors of AF after embolic stroke of undetermined source. When baseline NT-proBNP was available, only older age and elevation of this biomarker were predictive of subsequent AF. Understanding who is at higher risk of developing AF will assist in identifying patients who may benefit from more intense, long-term cardiac monitoring. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02239120.

The benefits and harms of intravenous thrombolysis with recombinant tissue plasminogen activator within 6 h of acute ischaemic stroke (the third international stroke trial [IST-3]): a randomised controlled trial.

BACKGROUND: Thrombolysis is of net benefit in patients with acute ischaemic stroke, who are younger than 80 years of age and are treated within 4·5 h of onset. The third International Stroke Trial (IST-3) sought to determine whether a wider range of patients might benefit up to 6 h from stroke onset. METHODS: In this international, multicentre, randomised, open-treatment trial, patients were allocated to 0·9 mg/kg intravenous recombinant tissue plasminogen activator (rt-PA) or to control. The primary analysis was of the proportion of patients alive and independent, as defined by an Oxford Handicap Score (OHS) of 0-2 at 6 months. The study is registered, ISRCTN25765518. FINDINGS: 3035 patients were enrolled by 156 hospitals in 12 countries. All of these patients were included in the analyses (1515 in the rt-PA group vs 1520 in the control group), of whom 1617 (53%) were older than 80 years of age. At 6 months, 554 (37%) patients in the rt-PA group versus 534 (35%) in the control group were alive and independent (OHS 0-2; adjusted odds ratio [OR] 1·13, 95% CI 0·95-1·35, p=0·181; a non-significant absolute increase of 14/1000, 95% CI -20 to 48). An ordinal analysis showed a significant shift in OHS scores; common OR 1·27 (95% CI 1·10-1·47, p=0·001). Fatal or non-fatal symptomatic intracranial haemorrhage within 7 days occurred in 104 (7%) patients in the rt-PA group versus 16 (1%) in the control group (adjusted OR 6·94, 95% CI 4·07-11·8; absolute excess 58/1000, 95% CI 44-72). More deaths occurred within 7 days in the rt-PA group (163 [11%]) than in the control group (107 [7%], adjusted OR 1·60, 95% CI 1·22-2·08, p=0·001; absolute increase 37/1000, 95% CI 17-57), but between 7 days and 6 months there were fewer deaths in the rt-PA group than in the control group, so that by 6 months, similar numbers, in total, had died (408 [27%] in the rt-PA group vs 407 [27%] in the control group). INTERPRETATION: For the types of patient recruited in IST-3, despite the early hazards, thrombolysis within 6 h improved functional outcome. Benefit did not seem to be diminished in elderly patients. FUNDING: UK Medical Research Council, Health Foundation UK, Stroke Association UK, Research Council of Norway, Arbetsmarknadens Partners Forsakringsbolag (AFA) Insurances Sweden, Swedish Heart Lung Fund, The Foundation of Marianne and Marcus Wallenberg, Polish Ministry of Science and Education, the Australian Heart Foundation, Australian National Health and Medical Research Council (NHMRC), Swiss National Research Foundation, Swiss Heart Foundation, Assessorato alla Sanita, Regione dell'Umbria, Italy, and Danube University.

Update on the third international stroke trial (IST-3) of thrombolysis for acute ischaemic stroke and baseline features of the 3035 patients recruited.

BACKGROUND: Intravenous recombinant tissue plasminogen activator (rtPA) is approved in Europe for use in patients with acute ischaemic stroke who meet strictly defined criteria. IST-3 sought to improve the external validity and precision of the estimates of the overall treatment effects (efficacy and safety) of rtPA in acute ischaemic stroke, and to determine whether a wider range of patients might benefit. DESIGN: International, multi-centre, prospective, randomized, open, blinded endpoint (PROBE) trial of intravenous rtPA in acute ischaemic stroke. Suitable patients had to be assessed and able to start treatment within 6 hours of developing symptoms, and brain imaging must have excluded intracranial haemorrhage and stroke mimics. RESULTS: The initial pilot phase was double blind and then, on 01/08/2003, changed to an open design. Recruitment began on 05/05/2000 and closed on 31/07/2011, by which time 3035 patients had been included, only 61 (2%) of whom met the criteria for the 2003 European approval for thrombolysis. 1617 patients were aged over 80 years at trial entry. The analysis plan will be finalised, without reference to the unblinded data, and published before the trial data are unblinded in early 2012. The main trial results will be presented at the European Stroke Conference in Lisbon in May 2012 with the aim to publish simultaneously in a peer-reviewed journal. The trial result will be presented in the context of an updated Cochrane systematic review. We also intend to include the trial data in an individual patient data meta-analysis of all the relevant randomised trials. CONCLUSION: The data from the trial will: improve the external validity and precision of the estimates of the overall treatment effects (efficacy and safety) of iv rtPA in acute ischaemic stroke; provide: new evidence on the balance of risk and benefit of intravenous rtPA among types of patients who do not clearly meet the terms of the current EU approval; and, provide the first large-scale randomised evidence on effects in patients over 80, an age group which had largely been excluded from previous acute stroke trials. TRIAL REGISTRATION: ISRCTN25765518.

Third international stroke trial (IST-3) of thrombolysis for acute ischaemic stroke.

BACKGROUND: Intravenous recombinant tissue plasminogen activator (rt-PA) is approved for use in selected patients with ischaemic stroke within 3 hours of symptom onset. IST-3 seeks to determine whether a wider range of patients may benefit. DESIGN: International, multi-centre, prospective, randomized, open, blinded endpoint (PROBE) trial of intravenous rt-PA in acute ischaemic stroke. Suitable patients must be assessed and able to start treatment within 6 hours of developing symptoms, and brain imaging must have excluded intracerebral haemorrhage. With 1000 patients, the trial can detect a 7% absolute difference in the primary outcome. With 3500 patients, it can detect a 4.0% absolute benefit & with 6000, (mostly treated between 3 & 6 hours), it can detect a 3% benefit. TRIAL PROCEDURES: Patients are entered into the trial by telephoning a fast, secure computerised central randomisation system or via a secure web interface. Repeat brain imaging must be performed at 24-48 hours. The scans are reviewed 'blind' by expert readers. The primary measure of outcome is the proportion of patients alive and independent (Modified Rankin 0-2) at six months (assessed via a postal questionnaire mailed directly to the patient). Secondary outcomes include: events within 7 days (death, recurrent stroke, symptomatic intracranial haemorrhage), outcome at six months (death, functional status, EuroQol). TRIAL REGISTRATION: ISRCTN25765518.