Skip to main content


The importance of rigorous ACT management during preclinical study procedures

During the preclinical testing of medical devices, one data point that regulatory officials are scrutinizing is the activated clotting time (ACT) of the animal model. ACTs are measured periodically while an invasive device is inserted in the vasculature This allows lab staff to monitor clotting time before and after the anti-coagulant (e.g. heparin) has been administered.

When any intra-vascular device is in contact with blood, one potential complication is unwanted clotting of the blood, or a thrombus formation in the vessel. This complication can be devastating to the patient and is why it’s important to control the coagulating conditions with the right dosing of an anticoagulant and proper maintenance of the ACT.

Those who are familiar with the use of blood contacting medical devices will be familiar with how ACT levels are monitored (through a simple blood test). Managing a spike or a decrease in the ACT value needs a fast-acting remedy to get the patient back to their target ACT range.

[Learn more about animal models at American Preclinical Services]

Why ACT levels present challenges in preclinical studies

In medical device testing, the FDA places more emphasis on ACT levels than one might be accustomed to seeing in a clinical setting.

“The FDA wants to know how these devices behave because in many circumstances, they’re worried about any potential clot forming on these devices,” says Dr. Mark Smith, Emeritus Chief Scientific Officer of American Preclinical Services (APS). “How this new device behaves in a preclinical model predicts how it’s going to behave in a clinic.”

Improper ACT levels can raise a red flag to regulators that the study wasn’t monitored properly, or it may raise other questions about the study and its results.

That’s why APS has developed careful procedures for administering anticoagulants and monitoring ACT levels, so that they remain within the target range during the procedure involving the evaluation of a blood contacting medical device. This is a prime example of why well-designed procedures are critical to a successful preclinical study that meets all the requirements of the regulatory agencies.

Developing the right protocols for ACT values during premedical testing

ACT Test tubes

In light of a more enhanced regulatory focus on the proper maintenance of ACT values during the preclinical testing of medical devices, APS has developed robust protocols.

  • Studies, experiments, internal documentation, and animal training provided the data set to lay the foundation for the protocols.
  • From this data, APS developed reference documents and reference guidelines to instruct the surgical staff. These processes are also tailored for species and animal weights so a specific dose of an anticoagulant is administered first as a loading dose and then as a continuous infusion dose (maintenance dose).

As a result of these processes, APS has achieved higher fidelity of ACT values that fulfills the expectations of the regulatory agencies evaluating the studies.  As Dr. Smith states. “We have fewer instances where we’re being asked about ACT by the clients and by the regulatory agency.”

[Learn more about what to expect with your APS preclinical program]

By aligning your ACT management protocol with what regulatory reviewers are looking for is one way APS can help you get your promising new device closer to market. Contact us to learn more.

Leave a Reply

Your email address will not be published. Required fields are marked *