Limited data are available on the efficacy of beta-blocker therapy for secondary prevention in Actue Coronary Syndrome(ACS) patients. This study sought to investigate the association of beta-blocker therapy at discharge with clinical outcomes in patients with ACS after percutaneous coronary intervention (PCI).

The American College of Cardiology (ACC)/American Heart Association (AHA) guidelines recommend beta-blockers for secondary prevention in patients with ACS without regard to reperfusion therapy. However, evidence supporting this recommendation originated from studies conducted before the introduction of reperfusion therapy or studies in patients treated with fibrinolysis. In the present era of PCI, there are no prospective randomized studies looking at the effects of long-term beta-blocker therapy on clinical outcomes in ACS patients. Moreover, results from registry data and post-hoc analysis on beta-blocker therapy in patients undergoing PCI are inconsistent.

In particular, the beneficial effect of long-term beta-blocker therapy has not been well established in patients with relatively low risk, such as preserved left ventricular systolic function or single-vessel disease. Therefore, we investigated the association of beta-blocker therapy at discharge with clinical outcomes in ACS patients after PCI.

Inclusion Criteria:

1. consecutive patients 18 years of age or older;
2. patients diagnosed as ACS(including STEMI、NSTEMI and UA) by doctor at discharge;
3. patients undergoing primary PCI.

Exclusion Criteria:

missing beta-blocker information.

The study population was selected from ten major cardiac centres in ShenZhen,CHINA.