American Heart Association - Guidelines & StatementsThe American Heart Association and American Stroke Association publish medical guidelines and scientific statements on various cardiovascular disease and stroke topics. AHA/ASA volunteer scientists and healthcare professionals write the statements. The statements are supported by scientific studies published in recognized journals and have a rigorous review and approval process. Scientific statements generally include a review of data available on a specific subject, an evaluation on its relationship to overall cardiovascular disease science, and often an AHA/ASA position on the basis of that evaluation.