 - Patients must not be receiving chronic daily treatment with aspirin 325 mgday or non-steroidal anti-inflammatory agents NSAIDs known to inhibit platelet function; the use of anti-platelet agents e.g. dipyridamole Persantine, ticlopidine Ticlid, clopidogrel Plavix is allowed only if patient is not receiving aspirin or NSAIDs known to inhibit platelet function 