Drug Coated Stents Comparable Or Better Than Bare Metal For Off-Label Use

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Main Category: Cardiovascular / Cardiology
Also Included In: Medical Devices
Article Date: 24 Jan 2008 - 3:00 PDT

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A new US study suggests that drug coated stents were as good as, if not better than, bare metal stents in off label use, even in higher risk patients. They were not linked to increased risk of death or heart attack when used off label or outside of their approved status for more complicated artery blockages, and were also more likely to prevent renarrowing of the arteries than bare metal stents.

The study is published in the online January 24th issue of the New England Journal of Medicine (NEJM) and is the work of Dr Oscar C Marroquin of the Cardiovascular Institute and the Department of Epidemiology, Graduate School of Public Health, at the University of Pittsburgh, and colleagues.

Stents are tiny mesh cylinders used to prop open blocked arteries as an alternative to bypass surgery. There are two principal types: bare metal, and drug eluting (drug coated). The drug eluting or coated types are about three times more expensive, but thought to be better at stopping the arteries narrowing again because they are coated with a chemical that prevents build up of scar tissue that attracts blood clots and cause blockages and renarrowing.

In the US, stents are approved by the Federal Drug Administration (FDA) to remove uncomplicated blockages in small straight sections of artery, but it is not illegal to use them for more complicated problems that are outside the FDA's approval (so called "off-label"). About half of the bare metal and coated stents fitted in the US are fitted "off-label".

Some studies have recently reported increased adverse cardiac events, such as heart attacks, following off-label use of drug coated stents. But no comparisons have been made with bare metal stents, so Marroquin and colleagues decided to investigate.

The researchers analyzed the records of 6,551 patients registered with the National Heart, Lung, and Blood Institute Dynamic Registry. They were able to find out whether each patient had been fitted with a coated or bare metal stent, and whether the procedure was on or off-label.

Off-label use was defined as using a stent to unblock restenotic lesions (renarrowing following a procedure), bypass graft lesions, left main coronary artery disease, or ostial, bifurcated, or totally occluded lesions. Also included was use in a reference-vessel diameter smaller than 2.5 mm or greater than 3.75 mm or a lesion longer than 30 mm.

The researchers recorded any deaths or cardiovascular events such as heart attacks among the patients for a further 12 months after their stents were fitted.

The results showed that:

• 54.7 per cent of bare metal stents and 48.7 per cent of drug eluting stents were fitted off-label.


• There was a higher rate of diabetes, hypertension, kidney disease, coronary artery disease in more than one artery, and previous heart procedures such as by-pass grafting, in patients fitted with coated as opposed to bare metal stents.


• However, 12 months after stents were fitted, there were no significant differences in adjusted risk of death or heart attack (myocardial infarction) in the drug coated stent group compared with the bare metal stent group.


• The risk of revascularization (renarrowing of the artery) was significantly lower among the drug coated stent patients than the bare metal stent patients.

Marroquin and colleagues concluded that their findings supported off-label use of drug eluting stents because:

"Among patients with off-label indications, the use of drug-eluting stents was not associated with an increased risk of death or myocardial infarction but was associated with a lower rate of repeat revascularization at 1 year, as compared with bare-metal stents."

In another study in the same issue of the NEJM, researchers from the State University of New York at Albany found that drug coated stents were not as effective as bypass surgery in treating multivessel blockages. They found that patients with blockages in more than one coronary blood vessel who had a bypass graft had a lower risk of death, heart attack, and repeat procedures than patients fitted with drug coated stents.

An editorial article in the same issue of the NEJM suggested that both studies may have been influenced by patient and doctor preference, and unmeasured confounders, and proposes a longer follow up to confirm the relative safety of drug eluting stents. However, the findings should help doctors and patients make better informed decisions, said the article.

"A Comparison of Bare-Metal and Drug-Eluting Stents for Off-Label Indications."
Marroquin, Oscar C., Selzer, Faith, Mulukutla, Suresh R., Williams, David O., Vlachos, Helen A., Wilensky, Robert L., Tanguay, Jean-Francois, Holper, Elizabeth M., Abbott, J. Dawn, Lee, Joon S., Smith, Conrad, Anderson, William D., Kelsey, Sheryl F., Kip, Kevin E.
N Engl J Med 2008 358: 342-352
Volume 358:342-352, January 24, 2008, Number 4

Click here for Abstract.

Sources: NEJM Jan 24th 2008: Marroquin et al, Hannan et al, Journal Watch.

Written by: Catharine Paddock
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