Trials involving other secondary prevention therapies also have influenced major practice guidelines used to formulate the recommendations in the present update. Thus, specific recom- mendations for clopidogrel use in post acute coronary syndrome or post percutaneous coronary intervention stented patients were included in the 2006 update, and recommendations regard- ing prasugrel and ticagrelor are added to this guideline on the basis of the results of the TRITON-TIMI 38 trial (Trial to Assess Improvement in Therapeutic Outcomes by Optimizing Platelet Inhibition With Prasugrel Thrombolysis in Myocardial Infarc- tion) and PLATO (Study of Platelet Inhibition and Patient Outcomes). The present update continues to recommend lower- dose aspirin for chronic therapy. The results of additional studies have further confirmed the benefit of aldosterone antagonist therapy among patients with impaired left ventricular function. The results of several trials involving angiotensin-converting enzyme inhibitor therapy among patients at relatively low risk with stable coronary disease and normal left ventricular function influenced the current recommendations.32 Finally, the recom- mendations for b-blocker therapy have been clarified to reflect the fact that evidence supporting their efficacy is greatest among patients with recent myocardial infarction (,3 years) and/or left ventricular systolic dysfunction (left ventricular ejection fraction #40%). For those patients without these Class I indications, b-blocker therapy is optional (Class IIa or IIb). The writing group confirms the recommendation introduced in 2006 for this guideline with regard to influenza vaccination. According to the US Centers for Disease Control and Prevention, vaccination with inactivated influenza vaccine is recommended for individuals who have chronic disorders of the cardiovascular system because they are at increased risk for complications from influenza.147 Additionally, the writing group added new sections on depression and on cardiovascular rehabilitation. 