Stents open arteries, but keep costs down

American Heart Association
Tuesday, 11 November 2003

Stents, which prop open narrowed arteries, are initially more expensive than balloon angioplasty alone, but they prove durable and cost-effective with time, according to research reported in today's rapid access issue of Circulation: Journal of the American Heart Association.

The study also examined the cost effectiveness of using a new blood thinner called abciximab after artery-opening procedures. The benefit depended on long-term survival.

"Stenting costs about $1,400 more at the outset," said senior author David J. Cohen, M.D., associate professor of medicine at Harvard Medical School in Boston. "But over one year, the stent essentially paid for itself because stents reduce the rate of restenosis (artery renarrowing)."

A stent is a wire mesh tube used to prop open an artery that's recently been cleared using angioplasty. The stent is collapsed to a small diameter and put over a balloon catheter. It's then moved into the area of the blockage. When the balloon is inflated, the stent expands, locks in place and forms a scaffold. This helps keep the artery open and improves blood flow to the heart. A stent may be used along with angioplasty.

The study, Controlled Abciximab and Device Investigation to Lower Late Angioplasty Complications (CADILLAC), enrolled 1,703 patients with acute myocardial infarction. Researchers randomized 846 patients to stenting alone and treated 857 patients with balloon angioplasty alone.

Health economists determine cost-effectiveness of treatments by calculating the "cost per quality-adjusted year of life gained," which is the ratio between the additional cost for the new treatment to the clinical benefit achieved. In the CADILLAC trial, the cost-effectiveness ratio for stenting was $11,237 per quality-adjusted year of life gained. Generally, treatments that cost less than $50,000 per quality-adjusted year of life gained are considered cost- effective. "So, by any reasonable standard, stenting in patients with acute MI is highly cost-effective," Cohen said.

Compared to balloon angioplasty, the use of stents added $1,148 to the procedural costs and the entire hospitalization cost $1,384 more. However, during the year after the procedure, follow-up costs for patients who received stents were $1,215 less than the follow-up costs for the balloon angioplasty patients. So the one-year cost was $18,859 for stenting and $18,690 for balloon angioplasty.

Sorting out the cost differences for stenting and balloon angioplasty was straightforward, but the economics of drug therapy related to the procedure aren't as clear, Cohen said.

Abciximab is a relatively new drug that reduces the risk of blood clots after procedures like stenting and balloon angioplasty, while heparin is an older drug that also "thins" the blood.

In the CADILLAC trial, the same patients who were randomized to stenting or balloon angioplasty were also randomized to either abciximab or heparin alone. Doctors treated 861 patients with abciximab and 842 with standard anticoagulation, Cohen said.

"At first it looked like there would be an advantage with abciximab because even though the drug is expensive ($1,148), the patients were discharged about a half day earlier, which offset the higher costs," he said.

But while stenting became a better buy with time, the opposite was true for abciximab. Follow-up costs added $1,244 to the bill, making the one year total $19,389 for patients treated with abciximab compared with $18,145 for patients treated with heparin. As a result, abciximab treatment was only cost-effective if it resulted in improved long-term survival for these patients – an issue still debated.

In an accompanying editorial, Jason H. Cole, M.D., and William S. Weintraub, M.D., of Emory University in Atlanta, Georgia, agreed that the cost data for stenting are persuasive. "The progression of understanding over the past few years has been clear: from no stents in primary angioplasty, to expensive stents, to stents whose costs are ultimately recouped within a year. In the current environment, one is tempted to say that a stent not only provides clinical benefit – it can almost be implanted for free." But, they noted that the use of abciximab remains an unsettled issue.

Co-authors are Ameet Bakhai M.D., MRCP; Gregg W. Stone, M.D.; Cindy L. Grines, M.D.; Sabina A. Murphy, MPH; Louise Githiora, BA; Ronna H. Berezin, MPH; David A. Cox, M.D.; Thomas Stuckey, M.D.; John J. Griffin M.D. and James E. Tcheng, M.D.

For more information, or to contact American Heart Association, see their website at: www.americanheart.org