Over the past 3 decades, percutaneous coronary intervention (PCI, or balloon angioplasty) has significantly changed the treatment of coronary artery disease (narrowing of the arteries supplying the heart muscle). Unlike the more invasive coronary artery bypass graft (CABG) surgery, angioplasty is a nonsurgical procedure in which a tiny catheter with a balloon is inserted into the coronary artery.
The balloon is then inflated to push aside the plaque causing the narrowing. Often a stent (wire mesh tube) is left in place to help keep the treated artery open; however, restenosis, or repeat narrowing, of the artery can occur over time. Drug-eluting stents were recently introduced to lower this risk of restenosis and have become an attractive alternative to bare-metal stents. However, they are much more expensive than bare-metal stents, and studies have shown no significant differences in rates of death or heart attack between patient groups receiving either type of stent.
Two articles that will appear in the Jan issue of CMAJ provide new insights into the use of drug-eluting stents.
The first is a research article by Grilli and colleagues in which they compare the use of drug-eluting stents for PCI in public versus private sectors of the Italian medical community. They also evaluate the effect PCI with drug-eluting stents has had on the volume of cardiac surgery, including traditional CABG surgery. They found that drug-eluting stents were used more frequently in private hospitals, with public hospitals using them more sparingly and selectively in patients with high-risk coronary artery disease. Overall cardiac surgery volumes decreased significantly in the public hospitals but remained stable in the private hospitals. The authors note that future assessments of the impact of drug-eluting stents need to consider the influence of system-wide financial and organizational incentives for adoption of their use.
In the second article, Ligthart and colleagues systematically review all published cost-effectiveness analyses comparing drug-eluting stents and bare-metal stents for PCI. They comment on how the conclusions of these analyses have differed despite using a relatively constant measure of the efficacy of drug-eluting stents. The factors they found to be associated with these different conclusions were study quality, funding source and country of origin.
In a related commentary, Knudtson examines the ongoing debates that surround the cost-effectiveness of drug-eluting stents and the clinical indications for their use. Knudtson notes that even the clinical indications for PCI have been questioned by the findings of a recent trial that has successfully challenged the long-held belief that an open artery is always worth striving for, even late in a heart attack.