At present, coronary angiogram is usually performed either through an artery in your groin or
wrist. An important limitation of the wrist approach is an increase rate of blockage of the
wrist artery. It is possible that the dose of blood thinner (i.e. heparin) may decrease the
risk of blockage. Early studies seem to suggest that higher dose is required to reduce the
risk of this important complication. However, to date there has not been a definitive study
to determine the most appropriate heparin dose for the prevention of this complication. The
main goal of this study is to determine the appropriate heparin dose to prevent wrist artery
blockage and to determine risk factors for developing such a complication.