MANCO: Measuring the ACT During Non-cardiac Arterial Procedures.

Heparin is used worldwide by all vascular surgeons and interventional radiologists (IR) during non-cardiac vascular interventions (NCVI), both open and endovascular. Heparin is used to reduce or prevent arterial thrombo-embolic complications (ATEC). Heparin reduces the clotting of blood and thereby coagulation. This also explains the negative side-effect of using heparin: its use can lead to bleeding-complications, possibly causing the need for blood tranfusions, more hematomas necessitating re-interventions and increasing the risk of infections.

Since the 1970's it is well known that heparin has a non-linear dose response curve and also a non-linear elimination curve in the individual patient.

Despite this fact, more than 95% of all vascular surgeons and IR use a standardized bolus of 5000 IU in every patient. Multiple studies have demonstrated that up to 70% of patients is not adequately anticoagulated during NCVI using that bolus of 5000 IU.

During open or endovascular cardiac interventions the effect of heparin is always routinely measured using the activated clotting time (ACT).

Despite this knowledge the percentage of vascular surgeons and/or IR that measure the effect of heparin during NCVI routinely is astonishing low: 0-5%, in the US this percentage is probably higher (30%), possibly due to medico-legal reasons. Existing guidelines on NCVI depict different regimes on the use of heparin or do not mention this use at all.