Dethrombosis to Enhance Acute Reperfusion in Myocardial Infarction - DEAR-MI


The goal of the trial was to evaluate treatment with the Pronto thrombus aspiration extraction catheter followed by percutaneous coronary intervention (PCI) compared with PCI alone among patients with ST elevation myocardial infarction (STEMI).

Study Design

Study Design:

Patients Enrolled: 148
Mean Follow Up: Index hospitalization
Mean Patient Age: Mean age 58 years
Female: 20

Patient Populations:

Consecutive patients with STEMI admitted within 12 hours of symptom onset scheduled for primary PCI.


Cardiogenic shock, previous MI or bypass surgery, bundle branch block or pacemaker induced rhythm on admission ECG, and contraindication to glycoprotein IIb/IIIa inhibitors.

Primary Endpoints:

Final myocardial blush grade 3 and complete ST resolution (≥70%)

Secondary Endpoints:

TIMI flow grade, TIMI frame count, and angiographic distal embolization

Drug/Procedures Used:

Patients with STEMI were randomized to either treatment with the Pronto thrombus aspiration extraction catheter followed by PCI (n=74) or primary PCI alone (n=74). Patients were also treated with glycoprotein (GP) IIb/IIIa inhibitors.

Concomitant Medications:

GP IIb/IIIa inhibitors

Principal Findings:

Baseline characteristics were well balanced between groups, with 46% anterior MIs and 18% diabetics. Stents and GP IIb/IIIa inhibitors were used in all patients. Direct stenting was used more often in the thrombus aspiration group (70% vs. 24%, p<0.0001). Thrombus aspiration was not performed in 7 patients in the aspiration group (9.5%) due to technical reasons.

The primary endpoint of complete ST resolution ≥70% occurred more frequently in the thrombus aspiration group compared with the primary PCI alone group (68% vs. 50%, p<0.05), as did the co-primary endpoint of final myocardial blush grade 3 (88% vs. 44%, p<0.0001). Final TIMI flow grade 3 did not differ by treatment group (89% vs. 78%, p=0.78), but corrected TIMI frame count was lower, i.e., faster in the thrombus aspiration group (17.3 frames vs. 21.5 frames, p<0.01). Distal embolization occurred less often in the thrombus aspiration group (5% vs. 19%, p<0.05), as did no reflow (3% vs. 15%, p<0.05). There was no difference in in-hospital major adverse cardiac events (1.4% each).


Among patients with STEMI scheduled for primary PCI, use of the Pronto thrombus aspiration extraction catheter was associated with higher rates of complete ST resolution and optimal myocardial blush grade 3 post-procedure compared with primary PCI alone.

The results of the present study, which showed improvements in myocardial perfusion as assessed by ST resolution and myocardial blush grade with use of the thrombus aspiration catheter, differ from the results in the EMERALD trial, which showed no difference in complete ST resolution with distal protection with the GuardWire device in the setting of primary PCI. While the results of the present trial are promising, larger studies would be needed to more fully evaluate the clinical efficacy of thrombus aspiration in primary PCI, particularly given the trend toward larger infarct sizes that was observed in the EMERALD trial.


Silva-Orrego P, et al. Thrombus Aspiration Before Primary Angioplasty Improves Myocardial Reperfusion in Acute Myocardial Infarction. J Am Coll Cardiol 2006;48:1552-9.

Presented by Dr. Pedro Silva at TCT 2005, Washington, DC.

Clinical Topics: Heart Failure and Cardiomyopathies, Invasive Cardiovascular Angiography and Intervention, Heart Failure and Cardiac Biomarkers

Keywords: Myocardial Infarction, Thrombosis, Diabetes Mellitus, Platelet Membrane Glycoprotein IIb, Stents, Percutaneous Coronary Intervention, Platelet Glycoprotein GPIIb-IIIa Complex

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