Clinical Conundrum

Should we thrombolyse a patient on warfarin?

This is a difficult question to which there is no evidence-based answer. By the very nature of the pathophysiology of ACS, it is unusual for patients who are on warfarin therapy to have an occlusive coronary event.

Clearly, the concern is that, following thrombolysis, these patients will be at increased risk of bleeding and, in particular, of intracranial haemorrhage. One could argue, however, that, in presenting with a STEMI, they need anti-thrombotic/ thrombolytic treatment even more because they have ‘broken through’ their anticoagulation.

How should we deal with this situation?

This situation will, as always, need to be dealt with on an individual patient basis balancing risks and benefits. However, in these cases, an urgent INR will help to inform the decision within a reasonable time frame (i.e. within 20 minutes).

A sub-therapeutic International Normalized Ratio (INR) (e.g. <2.0) would tend to favour administration of thrombolysis, particularly where the potential for benefit is great (e.g. anterior STEMI with an early presentation).

Cases where the INR is above the therapeutic range (e.g. >3.0) would contraindicate thrombolysis irrespective of the potential benefit because the risk of intracranial haemorrhage is likely to be much higher.

Where the INR is therapeutic (e.g. 2.0 – 3.0) the decision will have to be made based on likely benefit (territory of infarct, timing of presentation) balanced against risk of haemorrhage (advanced age, female gender, low body mass index).

What other approaches to treatment are there?

Other approaches to treatment to be considered: antiplatelet treatment should be given (i.e. aspirin) and, if it is available, PPCI will be a better alternative to thrombolysis in these patients.