Medical News Today -- Newly available information indicating that some patients vary in their genetic makeup in ways that may affect their response to clopidogrel (Plavix), and can prevent the medication from reducing their risk for heart attack, stroke and even death, the Food and Drug Administration (FDA) recently added a warning to the information for this drug. To help clinicians interpret the new FDA warning for this widely prescribed anti-platelet agent, the American College of Cardiology Foundation (ACCF) and the American Heart Association (AHA) released a joint clinical alert, shedding light on key issues for consideration and recommendations for practice.