FilterWire EX Randomized Evaluation - FIRE

Description:

The goal of the trial was to evaluate the safety and efficacy of distal microcirculatory protection with the novel filter-based catheter FilterWire EX compared with the GuardWire balloon occlusion and aspiration device during percutaneous coronary intervention (PCI) of diseased saphenous vein bypass grafts (SVGs).

Hypothesis:

The FilterWire EX distal protection device was noninferior to the GuardWire device.

Study Design

Study Design:

Patients Screened: 252
Patients Enrolled: 227
Mean Follow Up: 4 months
Mean Patient Age: 60 years
Female: 24

Patient Populations:

Age ≥21 years, and PCI with planned stenting of ≥1 de novo lesions in diseased SVGs

Exclusions:

Acute or recent MI or current elevation of creatine kinase-MB, uncontrollable allergy or contraindication to contrast or any of the study medications, cerebrovascular event within two months, serum creatinine ≥2.5 mg/dl, prior target vessel PCI within 30 days or planned multivessel intervention in which not all lesions met study enrollment criteria, SVG age <6 months, true aorto-ostial lesion ≤10 mm in length, reference vessel diameter <3.5 mm or >5.5 mm, TIMI 0 flow, lesion within 2.5 cm of the distal anastomosis or >2 cm of relatively straight vessel distal to the lesion not present, unprotected Y-limb branch vessel proximal to the study device, planned use of laser or atherothrombectomy devices, or left ventricular ejection fraction <25%

Primary Endpoints:

MACE at 30 days, including death, MI, or TVR

Drug/Procedures Used:

Patients undergoing PCI of SVG lesions were randomized to distal protection with the filter-based FilterWire EX (n=332) versus the GuardWire balloon occlusion and aspiration system (n=319).

Concomitant Medications:

Aspirin 325 mg prior to the procedure; clopidogrel (300 mg) or ticlopidine (500 mg) load recommended prior to the procedure or within four hours after the procedure; glycoprotein (GP) IIb/IIIa inhibitor at the discretion of the investigator; and intravenous heparin (activated clotting time to ≥300 seconds)

Principal Findings:

Among the 651 patients enrolled in the trial, there were 682 SVG lesions. Baseline clinical and angiographic characteristics were well balanced between the two arms, as were procedural success rates (95.5% with FilterWire vs. 97.2% with Guardwire, p=0.25). Bailout GP IIb/IIIa inhibitors were used slightly more frequently in GuardWire patients (1.5% vs. 0%, p=0.03), although the overall use was very low in both arms.

The primary endpoint of major adverse cardiac events (MACE) at 30 days occurred in 9.9% of FilterWire EX patients and 11.6% of GuardWire patients (p for superiority=0.53, one-sided p for noninferiority=0.0008). There were no differences in any component of the composite: death 0.9% versus 0.9%, p=0.99; myocardial infarction (MI) 9.0% versus 10.0%, p=0.69; and target vessel revascularization (TVR) 1.2% versus 1.9%, p=0.49, for FilterWire versus GuardWire, respectively.

Interpretation:

Among patients undergoing PCI of the SVG, use of the FilterWire EX distal microcirculatory protection device was noninferior with regard to the primary endpoint of MACE at 30 days compared with the GuardWire balloon occlusion and aspiration device.

The recent SAFER trial showed the benefit of GuardWire over a conventional angioplasty guidewire during SVG intervention. Similar MACE rates in the GuardWire arm were observed in the SAFER trial and the FIRE trial. The authors note that the results of the FIRE trial apply only to distal protection during PCI of diseased SVGs, and do not shed light on other settings such as primary PCI, or for other filter-based distal protection catheters.

References:

Stone GW, Rogers C, Hermiller J, et al., for the FilterWire EX Randomized Evaluation Investigators. Randomized comparison of distal protection with a filter-based catheter and a balloon occlusion and aspiration system during percutaneous intervention of diseased saphenous vein aorto-coronary bypass grafts. Circulation 2003;108:548-53.

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

Keywords: Myocardial Infarction, Balloon Occlusion, Saphenous Vein, Microcirculation, Angioplasty, Platelet Membrane Glycoprotein IIb, Stents, Percutaneous Coronary Intervention, Platelet Glycoprotein GPIIb-IIIa Complex


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