The study is aimed to optimized the dose-adjusted regimen of beta-blockers in patients with acute coronary syndrome by investigating therapeutic and curative results of target doses Beta-blockers using the dose-adjusted pathway of beta-blockers.

Inclusion Criteria:

• Age ≥ 18 years
• Patients diagnosed as acute coronary syndromes including acute ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevated acute coronary syndrome (NSTE-ACS)
• Patients or whose legal representatives signed written informed consent form

Exclusion Criteria:

Patients should been excluded if they meet any of the following exclusion criteria:

• Patients with contraindications to the application of beta blockers, including: 1) cardiogenic shock or heart failure (Killip grade > II level);2) sick sinus syndrome; 3) II degree atrioventricular block;4) unstable decompensation of cardiac failure (pulmonary edema, hypotension or low perfusion); 5) symptomatic hypotension or bradycardia (heart rate<50 beats/min, blood pressure<90/60mmHg); 6) contraindications to beta blockers or allergy to any ingredient of beta blocker; 7) active asthma should be treated by inhalation preparation treatment
• Pregnant or lactating women
• Patients without signed written informed consent
• Patients who was considered by the researcher inappropriate to participate in this study (for example, patients with a higher risk of cardiogenic shock, etc.)

Patients with acute coronary syndrome