Drug eluting stents should be used with caution in acute myocardial infarction

Drug-eluting stents are extremely effective devices to prevent restenosis following angioplasty. Yet, since last year, there is some debate and persistent uncertainty regarding the long term safety of these devices. Specifically, there is concern that some of these stents may occlude abruptly more than 1 year after placement, due to "late stent thrombosis".

Although this is a rare event (probably in the range of less than 1% per year) it is extremely severe, with patients dying in up to 45% of those cases. Therefore, there is concern that this rare but life-threatening event may offset the benefit achieved by drug-eluting stents in preventing restenosis.

The risk of such late stent thrombosis may be greater in the context of acute coronary syndromes and, in fact, little information is available so far from rigorous randomized clinical trials comparing drug eluting stents and the more conventional bare metal stents, in the context of acute coronary syndromes, particularly in the context of acute myocardial infarction. The randomized clinical trials which have compared drug-eluting stents and bare metal stents in the context of acute myocardial infarction are relatively small (totalling less than 1,000 patients with drug eluting stents) and most have only reported one year of follow-up.

This analysis used the database from the Global Registry of Acute Coronary syndromEs (GRACE), collected in 94 hospitals in 14 countries across 4 continents (Americas, Europe, Australia/NZ) to compare the survival up to 2 years of patients treated with bare metal stents only or receiving at least one drug eluting stent.

Survival appeared similar in the 6-months following discharge, but thereafter mortality was greater in patients treated with drug eluting stents. This difference was entirely related to patients treated for acute myocardial infarction and was associated with an increased risk of late reinfarction, suggesting that it may indeed be related to late stent thrombosis.

Although caution should always be exercised when analysing an observational study such as GRACE (in which patients who received drug eluting stents and bare metal stents were not similar), this survival difference (which persists after statistical adjustment for the differences in baseline characteristics between the two types of patients) suggests that DES should be used with caution in patients with acute myocardial infarction, at least until more evidence is accumulated of their long term safety from large studies with long term follow up.

Reference:
The GRACE registry is supported by sanofi-aventis and has been ongoing since 1999.
The coordinating center is at the Center for Outcomes Research,
University of Massachusetts Medical School
365 Plantation Street, Suite 185
Worcester, MA 01605
Phone: (508) 856-2275
Fax: (508) 856-5159
Web: www.outcomes.org

Notes

This study was presented at the ESC Congress 2007 in Vienna.

The European Society of Cardiology (ESC)

The ESC represents nearly 53,000 cardiology professionals across Europe and the Mediterranean. Its mission is to reduce the burden of cardiovascular disease in Europe.

The ESC achieves this through a variety of scientific and educational activities including the coordination of: clinical practice guidelines, education courses and initiatives, pan-European surveys on specific disease areas and the ESC Annual Congress, the largest medical meeting in Europe. The ESC also works closely with the European Commission and WHO to improve health policy in the EU.

The ESC comprises 3 Councils, 5 Associations, 19 Working Groups, 50 National Cardiac Societies and an ESC Fellowship Community (Fellow, FESC; Nurse Fellow, NFESC). For more information on ESC Initiatives, Congresses and Constituent Bodies see www.escardio.org.