OPTIMAS: OPtimal TIMing of Anticoagulation After Acute Ischaemic Stroke : a Randomised Controlled Trial

  • End date
    Sep 30, 2022
  • participants needed
  • sponsor
    University College, London
Updated on 26 January 2021
Marisa Chau
Primary Contact
St Peter's Hospital, Ashford and St. Peter's Hospitals NHS Foundation Trust (4.5 mi away) Contact
+43 other location
atrial fibrillation
holter monitor
ischemic stroke
electrocardiographic monitoring
anticoagulation therapy


OPTIMAS is a large, prospective, partially blinded randomised controlled trial of early (within 4 days [96hrs]) or standard (between day 7 and day 14 after stroke onset) initiation of anticoagulation after stroke in patients with atrial fibrillation (AF), using any licensed dose of a direct oral anticoagulant (DOAC). The trial will use a non-inferiority gatekeeper approach to test for non-inferiority of early anticoagulation followed by a test for superiority, if non-inferiority is established.


Current guidelines do not provide clear recommendations on the timing of OAC after acute AF-related stroke. Current United Kingdom (UK) guidelines for anticoagulation state that "delay for an arbitrary 2-week period is recommended" for "disabling" stroke and that anticoagulation can be started "no later than 14 days" for other strokes, at the prescriber's discretion.

OPTIMAS will investigate whether early initiation of DOAC treatment, within 4 days (96hrs) of onset, in patients with acute ischaemic stroke and AF is as effective as, or better than, standard initiation of DOAC treatment, no sooner than day 7 (>144hrs) and no later than day 14 (<336hrs) after onset, in preventing recurrent ischaemic stroke, systemic embolism and symptomatic intracranial haemorrhage (sICH)? Participants will be randomised 1:1 to the intervention or control. The exact timing of initiating treatment within each group is at the discretion of the treating clinician.

Condition Arrhythmia, Atrial Fibrillation, Cerebrovascular accident, Atrial Fibrillation (Pediatric), Stroke, Dysrhythmia, acute stroke
Treatment Direct oral anticoagulant (DOAC)
Clinical Study IdentifierNCT03759938
SponsorUniversity College, London
Last Modified on26 January 2021


Yes No Not Sure

Inclusion Criteria

Aged 18 years or over
Clinical diagnosis of acute ischaemic stroke
AF, confirmed by any of
12-lead ECG recording
Inpatient ECG telemetry
Other prolonged ECG monitoring technique (e.g. Holter monitor)
Known diagnosis of atrial fibrillation verified by medical records (e.g. primary care records, letter from secondary care)
Eligibility to commence DOAC in accordance with approved prescribing recommendations confirmed by treating physician
Uncertainty on the part of the treating physician regarding early versus standard initiation of DOAC

Exclusion Criteria

Contraindication to anticoagulation
Coagulopathy or current or recent anticoagulation with vitamin K antagonist (VKA) leading to INR 1.7 at randomisation
Thrombocytopenia (platelets < 75 x 10/L)
Other coagulopathy or bleeding tendency (based on clinical history or laboratory parameters) judged to contraindicate anticoagulation by treating clinician
Contraindication to early anticoagulation
Known presence of haemorrhagic transformation with parenchymal haematoma occupying >30% of the infarct volume and exerting significant mass effect (i.e. PH2) (NB: HI1, HI2 and PH1 are not considered contraindications)
Presence of clinically significant intracranial haemorrhage unrelated to qualifying infarct
Any other contraindication to early anticoagulation as judged by the treating clinician
Contraindication to use of DOAC
Known allergy or intolerance to both Factor Xa inhibitor and direct thrombin inhibitor
Definite indication for VKA treatment e.g. mechanical heart valve, valvular AF, antiphospholipid syndrome
Severe renal impairment with creatinine clearance (Cockcroft & Gault formula) <15 mL/min (i.e. 14 mL/min or less)
Liver function tests ALT > 2x ULN
Cirrhotic patients with Child Pugh score equating to grade B or C
Patient is taking medication with significant interaction with DOAC, including
Azole antifungals (e.g. ketoconazole, itraconazole)
HIV protease inhibitors (e.g. ritonavir)
Strong CYP3A4 inducers (e.g. rifampicin, phenytoin, carbamazepine, phenobarbital or St. John's Wort)
Pregnant or breastfeeding women
Presence on acute brain imaging of non-stroke pathology judged likely to explain clinical presentation (e.g. mass lesion, encephalitis)
Inability for patient to be followed up within 90 days of trial entry
Patient or representative refusal to consent to study procedures, including the site informing GP and healthcare professional responsible for anticoagulation care of participants
Any other reason that the PI considers would make the patient unsuitable to enter OPTIMAS
Note that current DOAC treatment is NOT an exclusion criterion, as long as the
treating physician considers it appropriate to restart (or continue) according
to the timings specified in the OPTIMAS trial protocol. Continuation of the
DOAC would be recorded as a start time of zero hours
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