William T Kuo presented the initial results of the multicenter PERFECT registry at CIRSE 2014 (the annual scientific meeting of the Cardiovascular and Interventional Radiological Society of Europe, 12–17 September, Glasgow, UK). He explained that systemic thrombolysis for acute pulmonary embolism carries up to a 20% risk of major bleeding, including a 2–5% risk of haemorrhagic stroke. Therefore, the registry set out to evaluate the safety and effectiveness of catheter-directed therapy as an alternative treatment for acute pulmonary embolism.
There were data from 101 consecutive patients receiving catheter-directed therapy for acute pulmonary embolism who were enrolled in the registry. Of these, 28 patients had massive pulmonary embolism and 73 had submassive pulmonary embolism. Massive pulmonary embolism patients were treated with immediate catheter-directed mechanical or pharmacomechanical thrombectomy; and submassive pulmonary embolism patients received catheter-directed thrombolysis via low-dose hourly drug infusion with tissue plasminogen activator (tPA) or urokinase.
Clinical success was defined as meeting all the following criteria: Stabilisation of haemodynamics; Improvement in pulmonary hypertension and/or right heart strain; and Survival to hospital discharge. The primary safety outcomes were major procedure-related complications and major bleeding events.
There were 53 men and 48 women with an average age of 60 years (range, 22–86 years) and mean body mass index of 31.03±7.20kg/m2. The average thrombolytic doses were 28±11mg tPA (n=74) and 2,697,101±936,287 international units for urokinase (n=23). Clinical success was achieved in 24/28 (85.7%) patients with massive pulmonary embolism and 71/73 (97.3%) with submassive pulmonary embolism. The mean pulmonary artery pressure improved from 51.17±14.06mmHg to 37.23±15.81 mmHg (n=92) (p<0.0001). Among patients monitored with follow-up echocardiography, 56/64 (87.5%) showed improvement in right heart strain. There were no major procedure-related complications, no major haemorrhages, and no haemorrhagic strokes.
In summary, catheter-directed thrombolysis improved clinical outcomes in acute massive and submassive pulmonary embolism patients while minimising the risk of major bleeding; therefore, these initial data support catheter-directed therapy as a first-line treatment option especially when systemic thrombolysis is contraindicated. “PERFECT is the first multicenter pulmonary embolism registry showing the clinical safety and effectiveness of CDT in a real-world population suffering from acute massive or submassive pulmonary embolism,” Kuo, associate professor, Interventional Radiology, Stanford University Medical Center, Stanford, USA, said.