Archives of Internal Medicine carries an article, from a multi-institutional team, that seems to show many cases where patients receiving drug-eluting stents don’t gain all that much benefit from the devices.

One part of the problem is the need to take anticlotting medications for at least a year, which carries risks and may have more potential for harm than not having the stent in the first place.

In addition, the research team adds that the unnecessary procedures are costing patients, healthcare facilities and insurance companies valuable resources that might be better used elsewhere. Robert Yeh, MD, MSc, of the Massachusetts General Hospital (MGH) Heart Center, the study’s corresponding author explains the problem:

“Both drug-eluting stents and bare metal stents help prevent reblockage of the coronary arteries, and drug-eluting stents further reduce that risk by inhibiting regrowth of tissue within the stent … While these procedures can save lives during an acute heart attack and improve the quality of life for many patients, being more sensible in our application of this technology could lead to substantial savings with minimal clinical impact.”

A stent is a small, wire, mesh tube that is placed into the artery to prop it up and hold it open, either after a blockage has been removed or where arteries are hardened and narrowing.

The use of stents coated in a drug was introduced in 2003, and helps to prevent tissue growing around the device that can occur in some patients with bare metal stents. Their usage increased rapidly, as the perceived desirability over basic metal only stents was in theory quite obvious.By 2005, they made up some 90% of all stent implants. Their use has fallen back to around 75%. Nonetheless, the cost per year from 2002 to 2006 is some $1.5 billion, just looking at the Medicare figures.

Yeh and colleagues designed a study to look at how drug-eluting stents are used in practice and to see if physicians were truly focused on selecting patients who would reap the most benefit from the device, when considering the risks. They took data from the National Cardiovascular Disease Registry (NCDR) of the American College of Cardiology and looked at the patients’ predicted risk of restenosis, and the potential impact of reducing usage among low-risk patients. A formula was used to take into account for other factors such as diabetes, the diameter of the treated artery and length of the initial blockage, and other clinical and demographic factors.

The work was impressively wide ranging with the NCDR CathPCI Registry being the largest U.S. clinical registry of patients undergoing cardiac angioplasty. Investigators analyzed information on some 1.5 million patients at more than 1,100 U.S. hospitals between January 2004 and September 2010. Only 13 percent were defined as being at high risk of restenosis, while 44 percent were at moderate risk and 43 percent were low-risk. In total, 77 percent of patients received drug-eluting stents: 83 percent of high-risk patients, 78 percent of moderate-risk patients and 74 percent of low-risk patients.

Study co-author John Spertus, MD, MPH, clinical director of Outcomes Research at Saint Luke’s Mid America Heart Institute in Kansas City, Missouri and the Lauer/Missouri Endowed Chair and Professor of Medicine at the University of Missouri – Kansas City said:

“The critical challenge in using stents is to be sure the decision reflects the patient’s preference, rather than the physician’s … If half the patients who find they are at low risk for restenosis choose bare metal stents to avoid the costs, bleeding risk and other complications associated with dual antiplatelet therapy, we could generate significant savings while better respecting patients’ preferences.”

Yeh, an instructor in Medicine at Harvard Medical School, added:

“We need to start thinking more about who is really going to benefit from drug-eluting stents, or really any technology, before we utilize it. Developing predictive clinical models that can help with risk/benefit assessment and finding ways to more effectively integrate those tools into our busy clinical routine are important challenges we are trying to overcome.”

Written by Rupert Shepherd