Assessment of Clinical Onset of IV Heparin in Interventional Cardiology and Cardiac Surgery

Adequate anticoagulation is achieved in cardiac surgery and interventional cardiology procedures with intravenous (IV) administration of unfractionated heparin. The Activated clotting time (ACT) is routinely measured to assess adequacy of anticoagulation to prevent clotting/thrombotic complications from placement of foreign materials used during cardiac surgery and cardiology procedures. Alternative methods to measure adequacy of anticoagulation such as measurement of Anti-Xa level and Reaction (R) time as assessed by Thromboelastrography (TEG) have also been suggested. However, their use in clinical practice is limited by lack of Point of Care (POC) technology and need for additional expertise to run these tests.

The efficiency and promptness of heparin anticoagulation is necessary during the structural heart procedures to minimize time from insertion of cannulae to valve deployment in cardiac surgery. The time required to prevent major complications is on the order of seconds to minutes. The goal of this study is to determine how rapidly the adequacy of heparin induced anticoagulation occurs using two different point of care ACT technologies (iSTAT and Hemochron). It is hypothesized that anticoagulation can be determined by the iSTAT ACT device 30 seconds after administration of heparin. Measuring heparin effectiveness at 30 or 90 seconds instead of the usual 3-minute time period may allow for earlier cardiac intervention.