Acute Pulmonary Embolism (PE) causes an abrupt increase in pulmonary artery pressure (PAP), leading to significant morbidity and mortality. Significant controversy exists surrounding the use of thrombolytic therapy in PE and is typically reserved for patients with massive PE. The purpose of this study was to evaluate the safety and efficacy of localized thrombolytic therapy for the treatment of acute PE without cardiovascular collapse (sub-massive PE) in reducing PAP.
A retrospective review of localized, catheter-directed thrombolytic therapy (CDTT) in patients with symptomatic sub-massive PE admitted to a single university medical center between June 2005 and April 2009 was performed. Tissue plasminogen activator (tPA) was administered via 2 catheters placed in both main pulmonary arteries at a dose of 0.45mg/hr per catheter for 24 ± 12hr. Hemodynamic data from pulmonary artery catheterization, systemic blood pressure, age, and oxygen tension obtained prior to administration of tPA were compared with post-infusion measurements. Outcomes were followed until hospital discharge.
20 patients (70% female) were included. Mean age was 52 (± 16) years. Patients were hypoxic and demonstrated new vascular filling defects in main pulmonary arteries (PA) on Computed Tomography Angiography. Mean pressures pre-tPA were 38 (± 10.2) and 36.4 (± 14.2) mmHg in the left and right main PA, respectively. After CDTT, there were significant decreases in PA pressures (Left: 24 ± 4.6 mmHg, p < 0.0001 and Right: 24.8 ± 4.1 mmHg, p < 0.01). All survivors were discharged from the hospital without exertional dyspnea or supplemental oxygen.
Localized thrombolysis led to a significant decrease in PAPs within 24–36 hours of tPA infusion. Although this cohort had a mortality of 25%, no specific complications were attributable to thrombolytic infusion. Survivors experienced resolution of symptomatic dyspnea and hypoxemia by hospital discharge. CDTT may be a safe and effective therapy for patients with symptomatic sub-massive PE.
Intrapulmonary therapy may be an effective alternative in sub-massive PE leading to rapid normalization of PAPs. Investigations into long-term outcomes of patients receiving localized thrombolysis versus conservative anticoagulation therapy seem warranted.
Susmita Rao, No Financial Disclosure Information; No Product/Research Disclosure Information