SHM's second edition of the Acute Coronary Syndrome (ACS) Implementation Guide is designed to enhance the efficiency and reliability of your quality improvement efforts in order to close the gap between best practices and what we currently do in caring for the inpatient with acute coronary syndrome (ACS). ACS is one of the top reasons for admissions in our hospitals and a major source of overutilization of resources—and therefore costs— for our institutions. The Implementation Guide is built on the foundation of the core principles of quality improvement, personal experiences and evidence-based medicine.