Why Have Stents Replaced Balloons? Underwhelming Evidence

Balloon angioplasty was conceived as a method of alleviating angina by opening obstructed coronary arteries without resorting to bypass surgery. Inflating a nondistensible balloon in a coronary artery results in expansion of the artery and disruption and rearrangement of the plaque, thus enlarging the stenotic lumen. In many patients, such disruption has permanently alleviated the stenosis that leads to ischemia; however, in some patients, acute thrombosis, dissection of the artery, or elastic recoil after deflation of the balloon results in an inadequate lumen with subsequent symptomatic renarrowing. Coronary stenting was first developed as a method to avoid the acute complications of balloon angioplasty. The availability of stents has led to a marked decline in the need for bypass surgery after an intervention. At Emory University from 1980 to 1990, approximately 5% of the patients requiring intervention had surgery during the hospital admission. That figure decreased to 2.75% from 1992 to 1995 and to 1.27% from 1996 to 2000, at which time stents were widely available. Stenting would inevitably also be used to address the other major limitation of angioplasty—restenosis during the healing phase.

After the pivotal Stress Restenosis Study (STRESS) (1) and Benestent (2) trials showed important reductions in restenosis with stenting, the technique received enormous enthusiasm. At present, stents are used in 80% to 90% of patients and in 70% to 80% of lesions. The most recent National Heart, Lung, and Blood Institute Dynamic Registry prospectively collected data on 1684 patients treated in 2000. Stents were used in 83.6% of the patients and 79.4% of the lesions. Data collected in 1998 and 1999 from the Northern New England Registry showed that percutaneous interventions included stents in 72% of the women and 79% of the men who were treated (3).

Obviously, interventional cardiologists favor stents. Stents are considered the …