Background: Acute coronary syndrome continues to have significant long-term morbidity and mortality. This study sought to compare baseline characteristics, practice patterns and clinical outcomes for patients with non-ST elevation acute coronary syndrome from a broad range of low-, middle- and high-income countries.
Methods and results: We compared the data from a prospective registry of patients with non-ST elevation acute coronary syndrome involving 4615 patients from 65 centers in 8 low and middle income countries (OASIS registry 2) with those obtained from 7987 patients from 95 centers in 6 middle and high income countries (OASIS registry 1). Patients in the OASIS registry 2 were younger, were more often males and smokers, presented later to the hospital after symptom onset and had a lower prevalence of diabetes at admission [with the exception of India, which had the highest age-adjusted prevalence (39.1%)]. There were marked variations in the angiography and intervention rates during the hospital stay, but the uses of proven pharmacological therapies were comparable. The two-year mortality rates adjusted for baseline covariates ranged from 6.9% to 15%. Patients from China had the lowest two-year mortality rate (6.9%) and patients from India had the highest rate (15%). Combining the two registries, the covariate-adjusted rate of death or myocardial infarction did not differ across countries with in-hospital angiographic rates of > or = 50% (17.1%), 25-49% (16.7%) or < 25% (16.5%). However, the covariate-adjusted rates for subsequent myocardial infarction (7.6%, 9.2% and 10.8% respectively, p < 0.0001), refractory angina (21.3%, 27.7% and 35.4% respectively, p < 0.0001) and the composite of death, myocardial infarction or refractory angina (34.9%, 40.7% and 46.8% respectively, p < 0.0001) differed depending on the angiographic rates.
Conclusions: Among the participating countries there was a marked heterogeneity in patient characteristics, coronary interventions, resulting in differences in the two-year composite rates of death, myocardial infarction and refractory angina among patients admitted with non-ST elevation acute coronary syndrome.