The purpose of this study is to evaluate the efficacy and safety of LCZ696 titrated to a target dose of 200 mg twice daily, compared to ramipril titrated to a target dose of 5 mg twice daily, in addition to conventional post-AMI treatment, in reducing the occurrence of composite endpoint of CV death, HF hospitalization and outpatient HF (time-to-first event analysis) in post-AMI patients with evidence of LV systolic dysfunction and/or pulmonary congestion, with no known prior history of chronic HF..