Pulmonary embolism breakthrough with clot-busting catheterization

Clinical takeaway: Catheter-directed thrombolysis now has randomized evidence behind it for intermediate-high risk PE, a population previously managed with anticoagulation alone. Guideline movement seems likely. 

Pulmonary embolism is the third most common cause of cardiovascular death, yet treatment has advanced little in recent decades. Patients at intermediate-high risk occupy an uneasy middle ground: their clots strain the right heart and can turn life-threatening but standard care has offered little beyond systemic anticoagulation drugs and close monitoring while the first critical days play out. 

Catheter-based treatment transformed the management of myocardial infarction and stroke, but no comparable shift reached pulmonary embolism, and anticoagulation remained the default for this population. Catheter-directed thrombolysis, which administers thrombolytic drugs through a catheter positioned at the clot itself, has long looked like a candidate: the procedure is simple, relatively inexpensive, and runs in a standard catheterization lab. What it lacked was a randomized test against standard care. An academic trial presented at ESC Congress 2026 now supplies that test, and the results give the interventional approach its strongest footing yet. 

Catheter-directed thrombolysis cut early adverse outcomes by 90% relative to anticoagulation alone. Only 0.7% of patients treated with the procedure reached the primary major adverse event endpoint within seven days versus 6.8% on standard care. The difference was driven primarily by fewer episodes of cardiorespiratory decompensation or collapse, not by a mortality gap. There were four deaths in the standard-care group within seven days and one in the thrombolysis group within 30 days, numbers too small to compare. Early improvement in right ventricular strain on echocardiography accompanied the clinical benefit, consistent with prior studies of the procedure. 

Overall bleeding did not differ between groups, 4.6% with thrombolysis versus 5.0% with standard care. But the two intracranial bleeds in the trial both occurred in the thrombolysis arm, a signal worth watching as longer-term and larger datasets accumulate. 

PRAGUE-26 randomized 558 patients with acute intermediate-high risk pulmonary embolism, defined by 2019 ESC criteria, to conventional catheter-directed thrombolysis or anticoagulation alone. The primary composite outcome comprised all-cause mortality, recurrent pulmonary embolism, and cardiorespiratory decompensation or collapse within seven days. Median age was 64, and 41% of participants were women. 

New ESC guidelines on pulmonary embolism are due next year, and the investigators expect PRAGUE-26 to inform them. In the US, the first joint AHA/ACC guideline on acute pulmonary embolism, published earlier this year gives catheter-directed thrombolysis a weak recommendation in this population, reserving it for selected patients who deteriorate.

The trial also functions as a proof of delivery: conventional catheter-directed thrombolysis, without ultrasound facilitation, was run across 11 Czech centers using the same model that carried interventional cardiology through myocardial infarction, suggesting the approach can scale where catheterization infrastructure already exists. 

"Using the blueprint already employed for heart attacks, we were able to demonstrate that specialized interventional treatment can be delivered in tertiary care centers across our national network," said Viktor Kočka, MD, PhD, professor of cardiology at Charles University and University Hospital Kralovske Vinohrady, Prague, who co-led the trial. "This may pave the way for an improved, standardized approach to the treatment of pulmonary embolism, reducing the acute risks that patients face." 

Source: Kočka V, et al. (2026 Aug 31) ESC Congress 2026. Prague 26: catheter-directed thrombolysis for pulmonary embolism