Thrombectomy in ST Elevation Myocardial Infarction - Thrombectomy in STEMI

Description:

The goal of the trial was to evaluate treatment with thrombectomy prior to percutaneous coronary intervention (PCI) compared with primary PCI alone among patients with ST elevation myocardial infarction (STEMI).

Study Design

Study Design:

Patients Enrolled: 215
Mean Follow Up: 30 days
Mean Patient Age: Mean age 64 years
Female: 22

Patient Populations:

Symptoms lasting >30 minutes and <12 hours, ST-segment elevation ≥2 mm in two contiguous leads, and coronary angiogram indicating need for PCI with an infarct-related artery suitable to thrombectomy

Exclusions:

Acute MI in the prior 30 days, left bundle branch block, prior coronary artery bypass grafting, left main stenosis, need for mechanical ventilation, or severe heart failure requiring intra-aortic balloon pump

Primary Endpoints:

Myocardial salvage as assessed by SPECT imaging at baseline and 1 month

Secondary Endpoints:

Final infarct size at 30 days, ST-segment resolution, corrected TIMI frame count, troponin T release, and MACE at 30 days

Drug/Procedures Used:

Patients were randomized to standard primary PCI (n = 107) or primary PCI with thrombectomy (n = 108) using the Rescue catheter. All patients were also treated with abciximab. Patients underwent sestamibi SPECT scans at baseline and 30 days.

Concomitant Medications:

Heparin (10,000 IU), aspirin (300 mg), and clopidogrel (300 mg)

Principal Findings:

Baseline characteristics were well-balanced between groups and relatively low risk, with 12% having had a prior MI, 7% diabetics, and 26% hypertensives, although 60% were current smokers. There was no difference in post-PCI TIMI grade 3 flow (89% for the thrombectomy group vs. 88% for the control group) or distal embolization (9% vs. 6%, p = 0.49). Procedure time was longer in the thrombectomy group (39 minutes vs. 29 minutes, p < 0.001).

There was no difference in the primary endpoint of myocardial salvage, although it trended lower in the thrombectomy group (median 13% vs. 18%, p = 0.12). Final infarct size was significantly larger in the thrombectomy group (15% vs. 8%, p = 0.004). Infarct size results were similar in the subgroup of patients with an anterior MI and in patients with visible thrombus. There was no difference in corrected TIMI frame count (16 frames for the thrombectomy group vs. 17 frames for the control group, p = 0.56), ST resolution 90 minutes post-PCI (62% vs. 60%, p = 0.94).

Troponin T release was greater in the thrombectomy group (p < 0.01). Frequency of major adverse cardiac events (MACE) at 30 days was identical in both groups (n = 2).

Interpretation:

Among patients with STEMI, use of thrombectomy prior to PCI was not associated with a difference in the primary endpoint of myocardial salvage compared with primary PCI alone. The secondary endpoint of infarct size was actually higher in the thrombectomy group compared with primary PCI, as was troponin T release. It is possible that use of the thrombectomy device may actually increase microembolization of thrombus, resulting in more myocardial damage than primary PCI alone.

References:

Kaltoft A, Bottcher M, Nielsen SS, et al. Routine thrombectomy in percutaneous coronary intervention for acute ST-segment-elevation myocardial infarction: a randomized, controlled trial. Circulation 2006;114:40-7.

Presented by Dr. Anne K. Kaltoft at TCT 2005, Washington, DC.

Clinical Topics: Cardiac Surgery, Invasive Cardiovascular Angiography and Intervention, Noninvasive Imaging, Aortic Surgery, Interventions and Imaging, Angiography, Computed Tomography, Nuclear Imaging

Keywords: Myocardial Infarction, Platelet Aggregation Inhibitors, Coronary Angiography, Thrombosis, Thrombectomy, Tomography, Emission-Computed, Single-Photon, Troponin T, Immunoglobulin Fab Fragments, Diabetes Mellitus, Stents, Percutaneous Coronary Intervention


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