Clot Treatment Trial Shows Benefit Over Blood Thinners Alone, Congress Hears

The PRAGUE-26 trial, presented at #ESCCongress and published in the New England Journal of Medicine, looked at patients with what doctors call intermediate-high–risk acute pulmonary embolism — a blood clot in the lungs serious enough to put strain on the heart but not yet causing full cardiovascular collapse. Researchers found that catheter-directed thrombolysis (a technique where a thin tube is guided directly to the clot to deliver clot-dissolving drugs at the site) led to a lower risk of death, a further clot, or serious deterioration of heart and lung function within seven days than anticoagulation — standard blood-thinning treatment — used on its own.

Pulmonary embolism (PE) is a condition where a blood clot, usually travelling from the legs, blocks one of the arteries supplying the lungs. The NHS describes it as a medical emergency. The intermediate-high–risk category sits in a clinically difficult middle ground — patients are unwell enough to be at real risk of rapid decline, yet the evidence on whether to use more aggressive clot-busting treatment alongside anticoagulation has, until now, been limited.

The PRAGUE-26 findings add to a growing body of evidence that more targeted intervention at this stage may change outcomes. But the trial was presented at a conference, and peer review and guideline bodies will need to assess the full data before clinical practice changes in the UK.

Anyone experiencing sudden breathlessness, chest pain, or coughing up blood should call 999 immediately — these can be signs of a pulmonary embolism. For non-emergency concerns about clot risk or existing treatment, NHS 111 or a GP appointment is the right first step.