Objective: To analyze the characteristics, treatment, and natural course during two years of the patients with acute coronary ischemic syndrome (ACS) without ST elevation in China as a part of the international multicentre registry of acute ischemic syndrome, Organization to Assess Strategies for Ischemic Syndromes (OASIS).
Methods: 2294 patients with ACS without ST elevation, including unstable angina pectoris and non-Q-wave myocardial infarction, aged 63 +/- 8, 62.3% being males, were registered and observed for 2 years based on informed consent in the northwest, north, and northeast China. The specific clinical protocols for patients were decided by the attending physicians without outside intervention. The patients' clinical characteristics, treatments, major events in hospital, and natural course of disease during the period of two years were recorded by filling in Case Report Forms offered by Canadian Cardiovascular Collaboration.
Results: 89.8% of the patients showed abnormal ECG. The most probable clinical diagnosis on admission was unstable angina in 88.5% of the patients and non-Q-wave myocardial infarction in the other 11.5%. 56.2% of the patients had past history of coronary artery disease, and nearly half of them had myocardial infarction. 57.4%, 18.3%, 47.6%, and 7.1% of them had the prior history of hypertension, diabetes, cigarette smoking and stroke respectively. During hospitalization, anti-platelet therapy and nitrate were used in 94.5% and 96.6% of the cases respectively, and 67.5%, 57.4%, and 59.1%t of them took beta-blockers, calcium antagonists and angiotensin-converting enzyme inhibitor (ACEI) respectively simultaneously. The medication rate dropped by 20.2% approximately 50.2% after discharge from hospital. During the two-year follow up the therapeutic rates of anti-platelets, nitrates, beta-blockers, calcium antagonists, and ACEI were 73.8%, 69.4%, 43.9%, 35.8%, and 31.6% respectively. During the 2 years 43.1%, 23.1%, and 8.2% of the patients underwent coronary angiography, percutaneous coronary intervention (PCI), and coronary artery bypass graft surgery (CABG) respectively. The two-year total mortality was 8.0%. The most common causes of death were severe arrhythmias or sudden death with an incidence of 4.3%. The major events were refractory angina, heart failure, new MI, stroke, and major bleeding with incidence rates of 29.4%, 15.4%, 7.9%, 4.8%, and 0.3%, respectively.
Conclusion: Most patients with acute ischemic syndrome without ST elevation in China are diagnosed as unstable angina. The patients with acute ischemic syndrome are diagnosed as unstable angina mostly in China. More than half of the patients are treated with anti-platelets, nitrates, beta-blockers, calcium antagonists, and ACEI during hospitalization. The medication rate gradually decreases after discharge. The two-year mortality is 8.0%. The most common causes of death include severe arrhythmias and sudden death.