1. Is the aPTT always used to monitor heparin therapy?
In a couple of situations it is not. 1. When very high doses of heparin are used, as may occur during open heart surgery, the aPTT loses its sensitivity - it will not clot. At this intense level of anticoagulation the Activated Clotting Time (ACT) is used as a monitoring tool instead of aPTT. 2. LMWH (low molecular weight heparin), which is a newer form of heparin cannot be monitored by the aPTT, but does not usually require monitoring. If it does, an anti-Xa assay can be used.
2. Should everyone have their aPTT checked?
This is not usually necessary. The aPTT is not used as a routine general screening test. It is used when someone has symptoms of abnormal bleeding or clotting. Asymptomatic patients are usually only screened prior to surgery - and then only if their doctor believes it is necessary to evaluate their risk of excessive bleeding during the procedure.
3. How can I change my aPTT?
The aPTT is not something you can change through lifestyle changes (unless perhaps you have a vitamin K induced factor deficiency). It is a reflection of the integrity of your clotting system. If your aPTT is prolonged due to acquired factor deficiencies, then addressing the underlying condition may bring the results to near normal levels. If they are prolonged due to a temporary or acute condition they should return to normal on their own within a short time period.
