Thrombus Aspiration is Associated with Improved 1 Year Mortality Rates in STEMI Patients: the Results of the 1 Year TAPAS Follow-Up Study
June 6, 2008 by Scott P. Williams [1], Leah H. Biller [2]
Groningen, Netherlands: Investigators from University Medical Centre Groningen published a 1 year follow-up of The Thrombus Aspiration during Percutaneous coronary intervention in Acute myocardial infarction Study (TAPAS) in which they demonstrated that thrombus aspiration prior to stenting improved clinical outcomes when compared to conventional percutaneous coronary intervention (PCI). Thrombus aspiration is hypothesized to decrease thrombotic complications that arise during PCI by removing clots and atherosclerotic plaque, and thereby reducing the potential for distal embolization. This 1-year follow-up study, published in the Lancet[1]. , builds upon the TAPAS investigator’s earlier finding that thrombus aspiration prior to stenting improved myocardial reperfusion for ST-segment elevation myocardial infarction (STEMI) patients.
TAPAS was a single center study of 1071 STEMI patients, randomized in a 1:1 ratio to thrombus aspiration or conventional PCI. All randomized patients were pretreated with 500 mg aspirin, 5000 IU heparin and a 600 mg loading dose of clopidogrel. Patients in the thrombus aspiration arm were treated using the Export Aspiration Catheter; patients in the conventional PCI arm were treated with standard balloon angioplasty and stent placement. During the procedure, patients in both arms were administered weight-adjusted abciximab. After treatment, all patients received standard therapies in accordance with current guidelines. One year follow-up data on clinical outcomes were obtained for 530 patients in each arm of the study.
The primary endpoint of this study was defined as cardiac death or non-fatal reinfarction during the 1 year follow-up period. Fewer instances of cardiac death occurred among patients in the thrombus aspiration arm when compared to patients in the conventional PCI arm (3.6% vs. 6.7%; hazard ratio 1.93; 95% CI 1.11-3.37; p=0.020). Similarly, instances of cardiac death or 1 year non-fatal reinfarction occurred less frequently among patients in the thrombus aspiration arm than in the conventional PCI arm (5.6% vs. 9.9%; HR 1.81; 95% CI 1.16-2.84; p=0.009).
Due to the original intent and design of TAPAS to evaluate myocardial reperfusion, the study had limited statistical power to assess the relationship between thrombus aspiration and overall clinical outcomes; nonetheless, the significant reduction in the occurrence of cardiac death and non-fatal reinfarction demonstrated in this 1 year follow-up TAPAS study suggests that thrombus aspiration prior to stenting may improve outcomes for STEMI patients.
The study was supported by Thorax Centre of the University Medical Centre Groningen and an unrestricted grant from Medtronic.