A simple indirect method to evaluate platelet aggregation; the Clot Retraction Inhibition (CRI) test

A simple indirect method to evaluate platelet aggregation is described: the Clot Retraction Inhibition (CRI) test, based on the observation that clot retraction is inhibited by previous in vitro platelet aggregation; a highly significant correlation exists between the inhibition of clot retraction and each of the three parameters of aggregation curves which have been evaluated by turbidometry. The CRI test is more sensitive in certain circumstances (thrombocytopenia, hyperlipaemia, contamination with red or white cells) than turbidometry. The CRI test can also be satisfactorily performed on citrated total blood.