The six cardiologists who founded the American Heart Association in 1924 would be amazed. From humble beginnings, the AHA has grown into the nation’s oldest and largest voluntary organization dedicated to fighting heart disease and stroke. A shared focus on cardiovascular health unites our more than 33 million volunteers and supporters as well as our more than 3,400 employees. Learn more about our impact over time. Heart disease is the No. 1 killer worldwide, and stroke ranks second globally. Even when those conditions don’t result in death, they cause disability and diminish the quality of life. We want to see a world free of cardiovascular diseases and stroke.