Efficacy and Safety of Thrombolytic Therapy in Acute Submassive Pulmonary Embolism: Follow-Up Study

Thrombolysis in acute submassive pulmonary embolism (PE) remains controversial. So we studied impact of thrombolytic therapy in acute submassive PE in terms of mortality, hemodynamic status, improvement in right ventricular function, and safety in terms of major and minor bleeding.

A single-center, prospective, randomized study of 86 patients was conducted at LPS Institute of Cardiology, G.S.V.M. Medical College, Kanpur, India. Patients received thrombolysis (single bolus of tenecteplase) with unfractionated heparin (UFH, group I) or placebo with UFH (group II).

Mean age of patients was 54.35 ± 12.8 years with male dominance (M:F = 70%:30%). Smoking was the most common risk factor seen in 29% of all patients, followed by recent history of immobilization (25%), history of surgery or major trauma within past 1 month (15%), dyslipidemia (10%) and diabetes mellitus (10%). Dyspnea was the most common symptom in 80% of all patients, followed by chest pain in 55% and syncope in 6%. Primary efficacy outcome occurred significantly better in group I vs. group II (4.5% vs. 20%; P = 0.04), and significant difference was also found in hemodynamic decompensation (4.5% vs. 20%; P = 0.04), the fall in mean pulmonary artery systolic pressure (PASP) (28.8% vs. 22.5%; P = 0.03), improvement in right ventricular (RV) function (70% vs. 40%; P = 0.001) and mean hospital stay (8.1 ± 2.5 vs. 11.1 ± 2.14 days; P = 0.001). There was no difference in mortality and major bleeding as safety outcome but increased minor bleeding occurred in group I patients (16% vs. 12%; P = 0.04).

Patients with acute submassive PE do not derive overall mortality benefit, recurrent PE and rehospitalization with thrombolytic therapy but had improved clinical outcome in form of decrease in hemodynamic decompensation, mean hospital stay, PASP and improvement of RV function with similar risk of major bleed but at cost of increased minor bleeding.