A Nod to Catheter-Guided Thrombolysis in Pulmonary Thromboembolism

Pulmonary thromboembolism (PTE) is the third most frequent cardiovascular disease, with an increasing prevalence over time. The stratification of these patients is paramount to decide their therapeutic approach, since there have been high mortality rates for certain subgroups.

Un guiño para la trombólisis guiada por catéter en tromboembolismo pulmonar

The European Society of Cardiology, in its latest guidelines (2019), classified the severity of PTE according to its risk of in-hospital/30-day mortality into low, low-intermediate, high-intermediate, and high (according to hemodynamic status and right ventricular involvement).

Patients at high intermediate risk constitute a subgroup of patients with an early mortality from 6% to 7.7%. Systemic administration of tenecteplasa in this population of the PEITHO study failed to reduce mortality, while reporting a significant increase in bleeding.

The aim of this work was to evaluate the safety of catheter-directed thrombolysis (CDT) in patients with intermediate-high risk PTE and compare it with the conventional strategy of anticoagulation alone.

Researchers included patients with proximal-segment PTE that lasts less than 14 days, with right ventricular dysfunction, and elevated cardiac markers. Patients with contraindications for thrombolytics or active cancer were excluded.

All patients received a heparin pump before undergoing an infusion of 1 mg/hour/catheter (20 mg total) through a thrombolytic infusion catheter (Cragg-McNamara) into each pulmonary artery. Echocardiographic (24 hours after) and tomographic (48 hours after, with severity evaluated through the Qanadli method) controls were conducted.

The primary endpoints (PEP) were the effectiveness of CDT, defined as improvement in right ventricular function (25% reduction in RV:LV ratio, 30% decrease in pulmonary artery pressure, 30% reduction in Qanadli score), and the safety of CDT, defined as absence of intracranial or life-threatening bleeding.

Twenty-three patients with intermediate-high risk PTE were randomized (12 to CDT and 11 to standard treatment). Their average age was 60 years old, 16% of them had a history of cancer, and the average Pulmonary Embolism Severity Index score was 89.

CDT was successful, with no peri-procedural events. The combined effectiveness PEP was better in patients with CDT (7 in 12 patients vs. 1 in 11; p = 0.0004). When performing the individual analysis, there were an improvement in the RV:LV ratio (p = 0.03), a reduction in pulmonary artery pressure (p = 0.001), and decreased thrombotic burden according to Qanadi (p = 0.45). When analyzing the safety PEP, there were no significant bleeding events (BARC type 5 or 3c).

Regarding the secondary endpoints, there was evidence of shorter stay in the critical care unit and shorter hospitalization time.

Conclusions

Despite its very small patient sample, this study demonstrated the safety of CDT, with improvement in hemodynamic parameters and hospitalization times.

The small number of patients does not allow for conclusions to be drawn on hard outcomes such as mortality, but it is still an encouraging and hypothesis-forming advance for larger studies in what is a promising technique for patients with intermediate-high risk PTE.

Dr. Omar Tupayachi.
Member of the Editorial Board of SOLACI.org.

Original Title: A pilot randomised trial of catheter-directed thrombolysis or standard anticoagulation for patients with intermediate-high risk acute pulmonary embolism.

Source: Kroupa J , et al. A pilot randomised trial of catheter-directed thrombolysis or standard anticoagulation for patients with intermediate-high risk acute pulmonary embolism. EuroIntervention [Internet]. 2022; Disponible en: https://eurointervention.pcronline.com/article/a-pilot-randomised-trial-of-catheter-directed-thrombolysis-or-standard-anticoagulation-for-patients-with-intermediate-high-risk-acute-pulmonary-embolism.