Thrombus Aspiration Before Stenting Benefits Patients Suffering Myocardial Infarction, Study Shows

Main Category: Cardiovascular / Cardiology
Article Date: 14 May 2008 - 3:00 PDT

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Medtronic, Inc. (NYSE: MDT) announced the presentation of new results from an independent study, which show that thrombus aspiration with Medtronic's Export Aspiration Catheter prior to stenting can significantly improve blood flow and survival rates in patients suffering acute myocardial infarction (AMI) compared to treatment with percutaneous coronary intervention (PCI) alone.

Called TAPAS, this randomized controlled trial will be presented at EuroPCR during the late-breaking clinical trials session. The presentation will be made by one of the investigators, Dr. Bart de Smet of the University of Groningen Medical Center in the Netherlands where the trial was conducted.

Previously published and presented results from TAPAS found that most AMI patients with ST-segment elevation achieved better reperfusion and clinical outcomes when receiving thrombus aspiration before standard PCI, regardless of their clinical and angiographic characteristics at baseline. (Thrombus, or blood clots, in coronary arteries can block blood flow, depriving the heart of oxygen.) The results have interested cardiologists worldwide, because many prior studies of thrombus aspiration have been negative or inconclusive. New findings from the TAPAS researchers' analysis of major adverse cardiac events (MACE) at one-year of follow-up are expected to be presented today to attendees of EuroPCR. MACE is a composite endpoint comprised of death, cardiac death, MI and target lesion revascularization (TLR).

"We are on the brink of a new development," Prof. Felix Zijlstra, a colleague at University Medical Center Groningen who collaborated on the research, told WebMD in an interview about the study when it was published in The New England Journal of Medicine (Feb. 7, 2008). "Instead of fragmenting clot material with a balloon and potentially sending it downstream, where it could cause further damage to the heart, it makes sense to get rid of the debris to start with."

Prof. Zijlstra presented results from TAPAS on March 30 at the 2008 meeting of the American College of Cardiology in Chicago. His ACC.08 presentation summarized the design and findings of the study: 1,071 AMI patients with ST-segment elevation were randomly assigned to thrombus aspiration using the Export Aspiration Catheter or to conventional PCI prior to coronary angiography. TAPAS is the first randomized controlled trial of an aspiration catheter to show a statistically significant reduction in death and MACE in the Export aspiration group. The Export group had 35 percent fewer patients than the conventional PCI group exhibiting angiographic signs of poor blood flow to the heart muscle. In addition, 28 percent more patients in the Export group had resolution of ST-segment elevation compared to the conventional PCI group.

Results from TAPAS are consistent with those from Medtronic's EXPORT study, a randomized controlled trial of 250 patients at 24 sites in Europe and India comparing the use of the Export Aspiration Catheter with conventional PCI. Reported at the Transcatheter Cardiovascular Therapeutics (TCT) meeting in October 2007 and recently accepted for publication by the European Interventional Journal, the EXPORT study demonstrated that primary aspiration with the Export Aspiration Catheter, followed by stenting, improved myocardial reperfusion in AMI patients.

Other research on thrombus aspiration will be presented at EuroPCR, including a meta-analysis performed by Dr. Giuseppe De Luca of Eastern Piedmont University in Novara, Italy. Part of the session titled, "Acute myocardial infarction: implementing evidence in daily practice," Dr. de Luca's presentation will summarize the findings of a meta-analysis that included 13 studies of various techniques for thrombus aspiration, including the Export Aspiration Catheter.

The session will be moderated by the EXPORT study's principal investigator, Dr. Bernard Chevalier of the Institut Cardiovasculaire Paris Sud in France. "Recent research underscores the potential benefits of thrombus aspiration in all AMI patients with ST-segment elevation, rather than the use of aspiration only in cases of high thrombus burden," Dr. Chevalier said.

About Medtronic

Medtronic, Inc., headquartered in Minneapolis, is the global leader in medical technology - alleviating pain, restoring health, and extending life for millions of people around the world.

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