Thrombus Aspiration During Percutaneous Coronary Intervention in Acute Myocardial Infarction - TAPAS

Jun 06, 2008
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Author/Summarized by Author:
Anthony A. Bavry, MD, MPH, FACC
Summary Reviewer:
Deepak L. Bhatt, MD, MPH, MBA, FACC
Trial Sponsor:
The Thorax Center of the University Medical Center Groningen covered the primary costs of the trial. Medtronic, Inc. provided a grant for angiographic analysis at the core laboratory.
Date Presented:
01/01/2008
Date Published:
01/01/2008
Date Updated:
06/06/2008
Original Posted Date:
06/06/2008
References

Description:

The goal of the trial was to evaluate a strategy of thrombus aspiration during primary percutaneous coronary intervention (PCI) compared with conventional PCI in patients with ST-elevation myocardial infarction (STEMI).

Hypothesis:

Thrombus aspiration during PCI will be more effective at improving myocardial perfusion grade than conventional PCI.

Study Design

  • Randomized

Patients Screened: 1,161
Patients Enrolled: 1,071
Mean Follow Up: 1 year
Mean Patient Age: 63 years
Female: 30

Patient Populations:

Patients with STEMI within 12 hours of symptom onset

Exclusions:

Rescue PCI after thrombolysis, presence of a comorbidity that conferred an estimated life expectancy of less than 6 months, and lack of informed consent

Primary Endpoints:

The primary endpoint was the post-procedural incidence of myocardial blush grade 0 or 1.

Secondary Endpoints:

Secondary endpoints were the incidences of TIMI flow grade of 3, complete ST-segment resolution, no persistent ischemic ST-segment changes, target vessel revascularization, reinfarction, bleeding, and death. A composite secondary endpoint was major adverse cardiac events. Clinical outcomes were assessed at 30 days and 1 year.

Drug/Procedures Used:

• Revascularization
• Stent

Principal Findings:

Baseline coronary angiography revealed Thrombolysis in Myocardial Infarction (TIMI) flow grade of 0 or 1 in 55% versus 60% (p = 0.23) and visible thrombus in 49% versus 44% (p = 0.14) for the aspiration group versus the conventional PCI group, respectively. The median time from hospital presentation until balloon inflation or aspiration was 28 minutes in the aspiration group and 26 minutes in the conventional PCI group (p = 0.92). Bare-metal stents were implanted in 92% of both groups. Mechanical aspiration was not performed in 10% of patients due to small or tortuous vessels. Platelet-rich thrombi were confirmed in 73% of aspirates.

Post-procedural myocardial blush grade of 0 or 1 was documented in 17% of the aspiration group and 26% of the conventional PCI group (relative risk [RR] 0.65, 95% confidence interval [CI] 0.51-0.83, p < 0.001). Complete ST-segment resolution was documented in 57% of the aspiration group and 44% of the conventional PCI group (RR 1.28, 95% CI 1.13-1.45, p < 0.001). No persistent ST-segment changes were present in 53% of the aspiration group and 41% of the conventional PCI group (RR 1.31, 95% CI 1.14-1.50, p < 0.001).

For aspiration versus conventional PCI, the incidence of death at 30 days was 2.1% versus 4.0% (p = 0.07). Mortality was highest (5.2%) among those with poor myocardial perfusion and lowest (1.0%) among those with good myocardial perfusion (p = 0.003). Thirty-day reinfarction was 0.8% versus 1.9% (p = 0.11), major bleeding was 3.8% versus 3.4% (p = 0.11), target vessel revascularization was 4.5% versus 5.8% (p = 0.34), and major adverse cardiac events were 6.8% versus 9.4% (p = 0.12) for aspiration versus conventional PCI, respectively.

All-cause mortality at 1 year was 4.7% versus 7.6% (p = 0.042), cardiac death was 3.6% versus 6.7% (p = 0.020), and reinfarction was 2.2% versus 4.3% (p = 0.05), respectively.

Interpretation:

Among patients who presented within 12 hours of a STEMI, a strategy of thrombus aspiration and stent implantation was superior to balloon predilatation and stent implantation. This approach improved myocardial perfusion, which was measured by myocardial blush grade, ST-segment resolution, and no persistent ischemic ST-segment changes. Good myocardial blush grade (for example, grade 3) strongly correlated with improved survival. Thrombus aspiration obviated the need for balloon predilatation in 55% of patients.

Thrombus aspiration also produced trends toward reduction in death and reinfarction at 30 days, which became significant by 1 year. Thrombus aspiration was feasible in most patients (approximately 90%) without any signal of procedural-related complications (for example, coronary dissection).

A strength of this trial was that randomization was performed prior to coronary angiography, thus minimizing selection bias. A limitation was the use of a surrogate primary endpoint; however, thrombus aspiration was still beneficial at reducing adverse clinical events.

References:

Thrombus Aspiration During Coronary Angioplasty for Acute Myocardial Infarction. Presented by Dr. Felix Zijlstra at the SCAI-ACC i2 Summit/American College of Cardiology Annual Scientific Session, Chicago, IL, March/April 2008.

Svilaas T, Vlaar PJ, van der Horst IC, et al. Thrombus aspiration during primary percutaneous coronary intervention. N Engl J Med 2008;358:557-67.

Vlaar PJ, Svilaas T, van der Horst IC, et al. Cardiac death and reinfarction after 1 year in the Thrombus Aspiration during Percutaneous coronary intervention in Acute myocardial infarction Study (TAPAS): a 1-year follow-up study. Lancet 2008;371:1915-20.

Keywords: Risk, Myocardial Infarction, Coronary Artery Disease, Pyridinolcarbamate, Suction, Blood Platelets, Percutaneous Coronary Intervention, Stents, Metals, Coronary Angiography, Selection Bias, Thrombosis, Confidence Intervals


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