Beta Blocker therapy is a mainstay of treatment following acute coronary syndromes (ACS), particularly acute myocardial infarction (MI). Studies have repeatedly demonstrated the benefit of Beta blocker therapy following either ST-segment elevation myocardial infarction (STEMI) or non-ST-segment elevation ACS,and Beta blocker therapy has been a performance measure used to grade hospital performance by the Centers for Medicare and Medicaid Services and Joint Commission on Accreditation of Healthcare Organizations.Although the benefit of Beta blocker therapy has been clearly demonstrated, the doses that have been used in many of these studies are significantly higher than those typically used currently in clinical practice.The benefit of Beta blockers has been ascribed to dose-related heart rate reduction,although alternative mechanisms for their benefit have also been proposed.In addition, the classical Beta blocker trials were performed decades ago, before the modern therapeutic era,which includes reperfusion therapy, potent antithrombotics, and statins. This raises the question of whether titration of Beta blocker therapy to the high doses that had been previously studied provides substantial incremental benefit in current clinical practice over the more frequently prescribed and clinically tolerated doses of Beta blockers.Moreover, a recent study has reported that high-dose Beta blockers were not superior to low-dose Beta blockers,aprovocative finding requiring validation. And until now, there has been no registry on patients with ACS about Between Beta-blocker Treatment in Henan, the most populated (about 100 million) and predominantly rural (66%)province in central China.

This multicenter, prospective, observational study is aimed to analyze the application status and long-term prognostic benefit of beta-blockers in patients with acute coronary syndrome.

1. Henan institute of cardiology epidemiology is responsible for design, data quality control and statistical analysis.
2. Data were collected using a uniformed Case Report Form(CRF) by trained staff at each hospital.
3. Sample size estimation: Based on retrospective observational cohort of ACS patients, 1-year mortality in beta-blocker recipients and non-beta-blocker recipients were 2.5% and 5.6%, respectively. To achieve a precision of 5% with an α of 0.05, the loss ratio of following-up is 15%.The investigators would need a sample of 3000.
4. Statistical analysis plan: the investigators will report summary statistics for patient characteristics, comorbidities, treatment strategies and outcomes. the investigators will also undertake the following prespecified subgroup analyses: age, sex, STE-ACS or NSTE-ACS, history of diabetes, history of hypertension, smoking.and analyze the association Between Beta-blocker Treatment and Long-term Mortality.
5. Quality assurance plan 1)Diagnosis of ACS is according to the third universal definition.2)Before registry, a training program on study objectives, data collection, and ACS management is given to the primary investigator and related staff at each participating center.3)Henan institute of cardiology epidemiology will regularly monitored at least 10% of CRFs for accuracy against medical records. If the CRFs are not completed with 98% accuracy, all CRFs are considered unqualified and this staff will be retrained.4)Before entering into the computer, data is queried for invalid and illogical values by research staff in Henan institute of cardiology epidemiology. Participating centres who has the high error rate of data, and no change in 6 months shall be deemed abandoned automatically; participating centres who has the high quality of data will be issued a certificate to reward.5)Investigator meeting will be annually held to conclude the progress, solve existing problems and strengthen program training.

Inclusion Criteria:

1. Age≥18 years.
2. Patients with clinical evidence of acute coronary syndrome, including ST segment elevation myocardial infarction (STEMI), non ST segment elevation myocardial infarction (NSTEMI) and unstable angina.
3. Informed consent signed by patients or legal guardians.

Exclusion Criteria:

• Expected survival <12 months

Anticipated 40 eligible sites in Henan province will participate. Each site will enroll patients who meet the inclusion criteria consecutively.