Inclusion Criteria:

• Cardiovascular disease (including history of stroke or transient ischaemic attack)
• Documented evidence of resistance to aspirin
• Capable of comprehending and communicating effectively with the investigator and staff and of providing informed consent.
• Willing to give informed consent prior to participation in the trial.

Exclusion Criteria:

• Any clinically significant condition other than cardiovascular disease.
• Clinically significant abnormal baseline haematology, blood chemistry or urinalysis findings.
• Use of dipyridamole, clopidogrel, ticlopidine or any non-steroidal anti-inflammatory agent (NSAID)(including COX-2 inhibitors) during the two weeks before randomisation and during the trial.
• Active peptic ulceration or history of peptic ulcer disease.
• Known history of or suspected hypersensitivity to dipyridamole, aspirin, any NSAID or any other component of the test drugs.
• History of any bleeding disorder.
• History of cerebral haemorrhage.
• Resting seated blood pressure less than 90/60mmHg.
• Participation in any drug clinical trial within sixteen weeks prior to the start of the trial.
• Any indication of current or previous abuse of alcohol, solvents or drugs.
• Asthma.
• Pregnant or nursing women or women of childbearing potential not using a medically approved means of contraception (e.g. oral contraceptives, intrauterine devices or surgically sterile).
• Previous participation in the randomisation phase of this clinical trial.