OASIS (Organization to Assess Strategies for Ischemic Syndromes)
To evaluate the variations between countries in invasive cardiac procedures and outcomes in patients with suspected unstable angina or myocardial infarction without initial ST elevation. Significant differences between countries were observed. The study concluded that higher rates of invasive and revascularisation procedures were associated with lower rates of refractory angina or readmission for unstable angina, no apparent reduction in cardiovascular death or myocardial infarction, but with higher rates of stroke and suggested that randomised trials should assess the relative impact of conservative and more aggressive approaches to invasive cardiac procedures and revascularisations in patients with unstable angina.
Data on clinical variables, procedures, and events were collected prospectively during the patient’s stay in hospital by means of standard forms. Data on transfers from one hospital to another for a procedure were also recorded. At 6 months, data were collected on all interim procedures, occurrence of myocardial infarction, readmission for unstable angina, and death. Events were not adjudicated.