COMPARISON OF ARTERIAL VERSUS VENOUS ACTIVATED PARTIAL THROMBOPLASTIN TIME MONITORING IN PERCUTANEOUS CORONARY INTERVENTIONAL PATIENTS
W. O'Brien*, P.P. Matsis.
Cardiac Care Unit, Wellington Hospital, Wellington.
Heparin is routinely administered during percutaneous coronary intervention (PCI) in order to prevent thrombus formation peri- and post-procedurally. The purpose of this study was to compare arterial vs venous activated partial thromboplastin time (APTT) in monitoring heparin's effect during PCI.
Twenty patients who were undergoing elective PCI were enrolled into the study. Samples were drawn at 2, 4 and 6 hours after heparin bolus for APTT using an automated bedside 2 channel Hemochron® 801 analyser. Samples were taken from the arterial sheath and peripheral vein and were then analysed simultaneously. At each time point a total of 3 samples were taken from the arterial sheath. Initially an amount equal to twice the arterial sheath dead space (DS), then 4 times the DS and then 6 times the DS was drawn prior to sample collection and analysis.
There was a statistically significant difference between venous APTT and arterial APTT after 2DS and 4DS, with no significant difference after 6DS withdrawls prior to sampling.
It was concluded that arterial APTT can be used to guide therapeutic decision making for heparin when the equivalent of 6 DS is withdrawn prior to analysis. Hence, arterial samples can be used to guide therapeutic heparin monitoring, avoid unnecessary venipunctures with possible complications and increased patient comfort.
