What is the American College of Cardiology/American Heart Association classification system?
The American College of Cardiology/American Heart Association classification system is a system used to designate a classification and a level of evidence for each recommendation. The system uses data available from clinical trials or registries about the usefulness/efficacy in different subpopulations, such as gender, age, history of diabetes, history of prior myocardial infarction, history of heart failure, and prior aspirin use. A recommendation with Level of Evidence B or C does not imply that the recommendation is weak. Many important clinical questions addressed in the guidelines do not lend themselves to clinical trials.