Efficacy and Safety Evaluation of 12-h and 2-h Urokinase Regimes in the Treatment of Pulmonary Thromboembolism: A Multi-Center, Randomized Controlled Trial in China

Pulmonary thromboembolism (PTE), a frequent life-threatening complication of deep vein thrombosis (DVT), is often underestimated and under diagnosed . Effective early treatment will decrease the mortality, reverse right heart dysfunction and reduce risk of chronic thromboembolic pulmonary hypertension (CTEPH) or post-thrombotic syndrome (PTS). Thrombolysis has proved to be the most rapid and effective therapy to reduce the obstruction of pulmonary circulation and normalize hemodynamic parameters. The ultimate goals of thombolytic therapy for this disease are to minimize early morbidity and mortality and to prevent recurrence without provoking excessive bleeding.

Currently, the choice of thrombolytic agents and regimens (either UK or rt-PA) is mostly based on personal or regional preferences. A loading dose of UK 4400 IU/kg followed by 2200 IU/kg/hour for 12 hours (UK-12h), or rt-PA 100 mg infusion over 2 hours are recommended for acute PTE treatment. However, increasing evidence suggest that UK infusion can be more concentrated and time can be further reduced. 100 mg/2 h of rt-PA and a novel dosing regimen of UK(3 million U/2 h) had been compared. The results indicated that a 2-h regimen of rt-PA and 2h UK exhibited similar efficacy and safety for treatment of acute PTE. UK-2h(20 000U/Kg) regimen combined with low molecular weight heparin (LMWH) had been used in Chinese population.No severe bleeding and allergic reaction occurred in the thrombolytic group. This dosage is much lower than that used by Goldhaber et al, but the efficacy was prominent. Until now,no study have been reported to compared UK-2h(20 000U/Kg) regimen with other UK regimens(such as UK-12h).

A relative lower dosage of UK 2-h regimen with body weight adjusted may be an alternative choice for treating PTE patients in Chinese population.Considering lower cost and convenience of this regimen, the efficacy and safety between UK-2h regimen(20 000U/Kg) and ACCP-approved UK-12h regimen for treating acute PTE will be compared.The study is conducted on patients with massive PTE with shock or hypotension and/or if without shock or hypotension but with right ventricular dysfunction. The clinical efficacy, emboli dissolving efficacy and safety will be evaluated.