In 1996, Johnson & Johnson was the undisputed king of bare-metal stents. Stents are the mesh tubes that prevent arterial collapse after balloon angioplasty, the principal treatment for atherosclerosis: A balloon is inserted into an artery to clear away plaque and is removed. Then a stent containing another balloon is inserted into the artery. The balloon is inflated to open the blocked artery and push the stent against the arterial walls; this balloon is then deflated and removed. J&J held a strong patent portfolio that gave it dominance in the U.S. stent market. It also led in Europe, where it faced stiffer competition.

Stents revolutionized the treatment of atherosclerosis in coronary and peripheral arteries, but they did little to address one of the chief problems with balloon angioplasty. In about 30 percent of cases, scar tissue formed around the site of the injury, causing the artery to close again, a setback called restenosis. Stents reduced the restenosis rate slightly, but it was still high.