Venous or arterial samples for activated clotting time measurements: a systematic review

Objective: The systematic review aims to investigate the effect of sampling source on activated clotting time (ACT) measurement within cardiovascular surgery and cardiac catheterisation. It also examines the evidence surrounding novel clot assessment techniques and associated sampling variation. Methods: A comprehensive electronic search was conducted using PubMed, MEDLINE, Scopus, Cochrane database, and Google Scholar until 20th June 2020. All studies reporting sampling source variability of ACT in cardiac surgery, vascular surgery and cardiac catheterisation were included. Results: Fourteen studies were included in the systematic review. Inconsistent reports of variability were seen in cardiac surgery and cardiac catheterisation. There were no studies directly examining ACT variability in vascular surgery. Novel clot assessment techniques have been validated in cardiac surgery, but measurements vary depending on sampling source. Conclusion: Sampling source should be kept consistent to facilitate effective haemostatic strategies. More research is needed regarding variability in vascular surgery and novel clot assessment techniques.