FIGURE 2. A, Number of stents known to be patent annually after deployment. The data in columns 1 through 6 refer to the number of patients with stents known to be patent without prior occlusion of this index metal stent at annual intervals. B, Annual cumulative total of occluded stents. The columns refer to annual totals of occluded stents. The difference between the number of stents known to have occluded at 3 years and the number known to be patent arises as the time to occlusion is not available for all patients.