Thrombectomy With Export Catheter in Infarct-Related Artery During Primary Percutaneous Coronary Intervention - EXPIRA

Description:

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

Hypothesis:

Thrombus aspiration during primary PCI will be more effective in improving myocardial perfusion and reducing infarct size.

Study Design

  • Randomized
  • Parallel

Patients Screened: 256
Patients Enrolled: 175
Mean Follow Up: 9 months
Mean Patient Age: 65 years
Female: 40%
Mean Ejection Fraction: 41%

Patient Populations:

  • STEMI with 9 hours from symptom onset
  • Culprit vessel at least 2.5 mm diameter
  • Thrombus score at least 3
  • TIMI flow 0 or 1 in culprit vessel
  • Age at least 18 years

Exclusions:

  • Previous intervention in the culprit vessel
  • Prior coronary artery bypass grafting
  • Cardiogenic shock
  • Left main disease or three-vessel disease
  • Severe valvular heart disease
  • Use of thrombolysis
  • Contraindication to a glycoprotein IIb/IIIa inhibitor

Primary Endpoints:

  • Myocardial blush grade 2 or 3
  • 90-minute ST-segment resolution of at least 70%

Secondary Endpoints:

  • Extent of microvascular obstruction
  • Infarct size

Drug/Procedures Used:

Patients with STEMI were randomized to thrombus aspiration with the Export catheter during primary PCI (n = 88) or PCI alone (n = 87).

Contrast-enhanced magnetic resonance imaging was performed on a subset of anterior STEMI patients during the acute phase at 3-5 days and again at 3 months.

Concomitant Medications:

Patients received aspirin 300 mg, clopidogrel 300 mg, intravenous heparin, and abciximab.

Principal Findings:

Overall, 175 patients were randomized. The mean age of participants was 65 years, 40% were female, mean left ventricular ejection fraction (LVEF) was 41%, and the time from symptoms until reperfusion was 6.1 hours. Direct stenting was performed in 76.2% of the thrombectomy group versus 2.3% of the PCI alone group (p = 0.0001). Drug-eluting stents were used in 58.3%, and bare-metal stents were used in 41.7%.

The incidence of the first co-primary endpoint, myocardial blush grade 2 or 3, occurred in 88.6% of the thrombectomy group versus 59.8% of the PCI alone group (p < 0.0001). The incidence of the second co-primary endpoint, ST-segment resolution of at least 70%, occurred in 63.6% of the thrombectomy group versus 39.1% of the PCI alone group (p = 0.001).

In the acute phase, microvascular obstruction occurred in 31.5% versus 72.9% (p = 0.0005), respectively. At 3 months, infarct size was 9% versus 11% (p = 0.2) and LVEF was 49.0% versus 46.7% (p = 0.3), respectively. At 9 months, cardiovascular death occurred in 0% of the thrombectomy group versus 4.6% of the PCI alone group (p = 0.02).

Interpretation:

Among patients with STEMI, thrombus aspiration during primary PCI is beneficial at improving myocardial blush grade and ST-segment resolution. Although there was reduced microvascular obstruction during the acute phase with thrombectomy, at 3 months, infarct size and LVEF were similar between the groups. Cardiovascular death was observed less frequently in the thrombectomy group at 9 months. Thrombectomy allows for more direct stenting, which may partly explain the beneficial findings of this approach.

This study is limited by small sample size. Also, outcomes of reperfusion (myocardial blush grade and ST-segment resolution) were not assessed in a blinded fashion. However, the findings of EXPIRA complement the TAPAS trial (Svilaas T, et al. N Engl J Med 2008;358:557-67) and recent meta-analysis (Bavry AA, et al. Eur Heart J 2008;29:2989-3001), which document a reduction in clinical outcomes with thrombectomy prior to primary PCI.

References:

Sardella G, Mancone M, Bucciarelli-Ducci C, et al. Thrombus aspiration during primary percutaneous coronary intervention improves myocardial reperfusion and reduces infarct size. The EXPIRA (thrombectomy with EXPort catheter in Infarct Related Artery during primary percutaneous coronary intervention) prospective, randomized trial. J Am Coll Cardiol 2009;53:309-15.

Clinical Topics: Cardiac Surgery, Invasive Cardiovascular Angiography and Intervention, Noninvasive Imaging, Aortic Surgery, Interventions and Imaging, Magnetic Resonance Imaging

Keywords: Complement System Proteins, Myocardial Infarction, Metals, Thrombosis, Drug-Eluting Stents, Thrombectomy, Stroke Volume, Magnetic Resonance Imaging, Percutaneous Coronary Intervention


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