Catheter-directed thrombolytic intervention is effective for patients with massive and submassive pulmonary embolism

Background: Massive pulmonary embolism (MPE) is a significant cause of mortality and, with submassive pulmonary embolism (SPE), is associated with chronic thromboembolic pulmonary hypertension, resulting in ongoing patient morbidity. Standard treatment is anticoagulation, although systemic thrombolytic therapy has been shown to reduce early mortality in patients with MPE and improve cardiopulmonary hemodynamics in patients with SPE. However, systemic lysis is associated with significant bleeding risk. Early reports of catheter-directed techniques (CDT) suggest favorable outcomes in patients with MPE and SPE with reduced risk of hemorrhage. The purpose of this study is to evaluate efficacy and safety outcomes in MPE and SPE patients treated with CDT.

Methods: Seventeen patients treated with CDT for MPE and SPE were clinically and hemodynamically evaluated. Patients were grouped by severity of pulmonary embolism: MPE (n = 5) or SPE (n = 12). Pre- and post-interventional measures were assessed, including pulmonary artery pressures (PAPs), cardiac biomarkers, tricuspid regurgitation, right ventricular (RV) dilatation, and systolic function. Nine patients had contraindications to systemic thrombolytic therapy.

Results: PAP was elevated in 94% at presentation. The average dose of recombinant tissue plasminogen activator (rt-PA) was 31 mg; 44 mg in MPE and 26 mg in SPE. Pre- and post-intervention PAPs were recorded in 13 patients. All demonstrated an acute reduction in posttreatment PAP, averaging 37%. At presentation, all MPE and 10 (83%) SPE patients showed both RV dilatation and reduced function on echocardiography, which normalized in 76% (13/17) and improved in 24% (4/17) after CDT. Patients who demonstrated left ventricle underfilling before CDT (2 [40%] MPE and 2 [20%] SPE) normalized after CDT. All MPE and 11 (92%) SPE patients had tricuspid regurgitation on echocardiography pretreatment, which resolved in 60% and 58% of MPE and SPE patients, respectively. One delayed mortality occurred in an MPE patient who was hypotensive and hypoxic at presentation. There was one puncture site bleed.

Conclusions: CDT was successful in the acute management of patients with MPE and SPE. CDT rapidly restores cardiopulmonary hemodynamics using reduced doses of rt-PA. These observations suggest that CDT should be considered in MPE and SPE patients to rapidly restore cardiopulmonary hemodynamics, reduce acute morbidity and mortality, reduce bleeding complications, and potentially avoid long-term morbidity.