Coronary Artery Disease: A Plague of Plaque Heart specialists are working to identify certain deadly plaques that build up along the coronary artery walls and are liable to swell and rupture, thus causing speedy blood clot formation and blockage of blood flow to the heart. One doctor calls this potential discovery "the Holy Grail of cardiology." Coronary artery disease kills as many as 500,000 Americans each year despite the ever-increasing use of treatments, such as balloon angioplasty, stent placement, bypass surgery, and blood-thinning medications. If scientists learn to isolate and treat the killer plaques, they could revolutionize heart therapy, saving countless lives.