Comparision Between Activated Partial Thromboplastin Time Versus Anti-Xa Activity in Heparin Monitoring

Summary

Participation Requirements

Description

Aim of the study Based on available data, a randomized trial aimed at comparing the efficacy and safety of monitoring UFH treatments using aPTT and anti-FXa activity in patients treated with fulldoses of UFH could validly be carried out. Study design Primary objectives: safety and efficacy Secondary...

Aim of the study Based on available data, a randomized trial aimed at comparing the efficacy and safety of monitoring UFH treatments using aPTT and anti-FXa activity in patients treated with fulldoses of UFH could validly be carried out. Study design Primary objectives: safety and efficacy Secondary objectives: efficiency and cost effectiveness Primary evaluation criteria: bleeding complications (n, %) and thrombotic complications Secondary evaluation criteria: percentage of test results within the therapeutic range,number of tests perfomed per day, number of daily dose adjustments, total dosage of heparin given to the patients, mean time to achieve therapeutic anticoagulation, transfusion rates, health economics analysis (total treatment cost) Calculation of number of patients to be evaluated: According to the only randomized study published to date (A), the bleeding rate was 1.5% (n=1/65) in the group of patients monitored using Anti-FXa activity vs. 6.1% (n=4/66) in theaPTT group. The difference was not significant (p=0.36) due to the lack of power of the study (n=131 patients). Taking into account these bleeding risks and 0.05 as the alpha risk and 0.20 (0.05) as the beta risk, the number of patients to be included would be 323 (506) in each treatment arm. Description of the two monitoring strategies Patients should be randomized to be monitored using either: Anti-Xa activity (heparin levels) with the therapeutic range between 0.30 and 0.70IU/mL (corresponding to 0.2 to 0.4 protamine sulfate titration assay) (3). aPTT wIth the usual therapeutic range of 1.5 to 2.5 fold the control time, which was the usually used therapeutic range in the institution. Example of nomogram for heparin dose-adjustment when monitored using aPTT or anti-Xa activity (12)Practical considerations Mechanism of randomization: electronic After randomization, the patients must be monitored using either anti-Xa activity or aPTT. Only that specific test should be prescribed by the ward, and only that the corresponding test result be given by the laboratory. Ideally, fresh patients samples should be evaluated for both Anti-Xa activity and aPTT, data being recorded, but only the prescribed test should be given to the ward. In addition, it would be necessary to store aliquots (0.5-1.0 mL each) of plasmas samples frozen at -70°C for control purpose. Patients must be follow-up at 3-months Data to be collected: Patients demographical data (sex, age), indication of UFH therapy (VTE, ACS, other…),comorbidity (cancer, pregnancy, postoperative period, other…), concomitant therapy (medication such as oral contraceptive…) , previous history of thrombosis (DVT, ACS,stroke, other…) Duration (in hours) and total dosage (IU) of heparin therapy before randomization (if any) Route of administration (IV, SC), daily heparin dosage (IU), duration of treatment, time to achieve therapeutic range, number of dosage change per day, laboratory test results (anti-Xa activity or aPTT) Outcome: death (any cause (to be recorded), description of any bleeding complication (when, localization, classification as major or minor…) or recurrence of thrombosis (when,localization…) while on UFH therapy and within the 3-month follow-up.

Tracking Information