High Recurrence Rates After First Episode of Stent Thrombosis: Dutch Stent Thrombosis Study

March 29, 2008

March 29, 2008 (Chicago, IL) - Data from a European registry have shown that recurrent stent thrombosis is common in patients who have had an initial thrombotic event after stent implantation [1]. Investigators report a definite stent thrombosis recurrence in nearly 20% of patients who had an initial event; nearly 15% of patients who had a first episode of stent thrombosis died during follow-up.

"The study shows that it is not the end if a patient suffers a stent thrombosis, but it is a high-risk population with a very high recurrence rate and a very high mortality rate," senior investigator Dr Jurriën ten Berg (St Antonius Ziekenhuis, Nieuwegein, the Netherlands) told heartwire . "We have to do everything we can to prevent the first stent thrombosis."

The results of the trial, known as the Dutch Stent Thrombosis Study, were presented today during the late-breaking clinical-trials session at the American College of Cardiology 57th Annual Scientific Session/i2 Summit-SCAI Annual Meeting in Chicago, IL by lead investigator Dr Jochem Wouter van Werkum (St Antonius Ziekenhuis, Nieuwegein, the Netherlands).

Speaking with heartwire , study investigators noted that the Dutch registry is the largest stent-thrombosis registry with the longest follow-up to date, and is important because "stent thrombosis remains the dark side of coronary stenting," affecting between 1% and 4% of patients. The purpose of this study, said ten Berg, was to evaluate the short- and long-term clinical outcomes after a "definite" stent thrombosis and to identify predictors of adverse clinical outcomes.

Multicenter, observational trial

In this multicenter, observational study, investigators enrolled all consecutive patients with definite stent thrombosis as confirmed by angiography between January 2004 and February 2007. In total, 431 patients were enrolled, a majority of whom were male. More than 60% of patients were initially implanted with a bare-metal stent and 35% received a drug-eluting stent. In terms of the timing of the stent thrombosis, 32% had an acute stent thrombosis, 41% had a subacute thrombosis, and 26% had a late or very late stent thrombosis.

During a median follow-up of 27 months, 18.8% of patients experienced a second definite stent thrombosis and 12.3% of patients died of cardiac causes. In terms of the primary end point, 72.1% of patients were free of cardiac death or recurrent stent thrombosis at three years. van Werkum pointed out that 6.0% and 9.3% of patients experienced cardiac death or a definite recurrent stent thrombosis, respectively, in the hospital. At three years, all-cause mortality was 15.4% among those who experienced a stent thrombosis.

Investigators report that diabetes mellitus and impaired left ventricular ejection fraction were predictors of adverse outcomes after a first stent thrombosis, as was severe calcification, LAD stenting, and total stent length. Patients who had an additional stent implanted during emergency treatment for the first episode of stent thrombosis were more than four times as likely to experience a repeat episode of stent thrombosis. The type of stent--bare metal or drug eluting--and the timing of the stent thrombosis were not associated with adverse outcomes.

"It goes to show us that regardless of whether the stent thrombosis occurred in patients with a bare-metal stent or a drug-eluting stent, it doesn't matter," ten Berg told heartwire . "The damage has already been done."

Recurrent stent thrombosis not rare

Dr Roxanne Mehran (Columbia University Medical Center, New York), the scheduled discussant during the presentation, said that it is important to consider the timing of stent thrombosis, especially how it relates to the mechanism and the resulting treatment options.

"It is important for us to know and to separate the different kinds of stent-thrombosis outcomes," said Mehran. "In this registry, acute and subacute thrombosis was overrepresented, and this might have led to the observed high recurrence rates." She added that although clinicians are concerned with recurrence rates, what they really want to know about are conventional clinical end points, such as death and MI, and suggested that the study should have used this as an end point instead.

She said that although the majority of patients were treated with bare-metal stents, and despite the fact that there was no difference in recurrence rates among those treated with a bare-metal and those treated with a drug-eluting stent, the study was not powered to identify differences between the stent subsets.

"Stent thrombosis is a significantly morbid event, and recurrent stent thrombosis is not rare," she concluded.

The Dutch Stent Thrombosis Study is sponsored by an unrestricted grant from Sanofi-Aventis.

  1. van Werkum, JW, deKorte FI, Heestermans AA, et al. High recurrence rates after a first episode of stent thrombosis: Results from the Dutch Stent Thrombosis Study. American College of Cardiology Scientific Sessions/i2 Summit-SCAI Annual Meeting; March 29, 2008; Chicago, IL.

The complete contents of Heartwire , a professional news service of WebMD, can be found at www.theheart.org, a Web site for cardiovascular healthcare professionals.


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