Single High-Dose Bolus Tirofiban and Sirolimus-Eluting Stent vs. Abciximab and Bare-Metal Stent in Myocardial Infarction - STRATEGY

Description:

The goal of the trial was to evaluate the clinical and angiographic differences comparing treatment with a single, high-dose bolus of tirofiban plus sirolimus-eluting stenting (SES) versus abciximab plus bare-metal stenting (BMS) among patients with ST elevation myocardial infarction (STEMI).

Study Design

Study Design:

Patients Screened: 219
Patients Enrolled: 175
Mean Follow Up: Eight months
Mean Patient Age: Median age 63 years
Female: 27

Patient Populations:

Chest pain for >30 minutes with ST-segment elevation of ≥1 mm in ≥2 contiguous leads or with presumably new left bundle branch block; and admission either within 12 hours of symptom onset or between 12 and 24 hours with evidence of continuing ischemia

Exclusions:

Administration of fibrinolytic agents in the previous 30 days, history of bleeding diathesis or allergy to the study drugs, major surgery within 15 days, and active bleeding or previous stroke in the last six months

Primary Endpoints:

Composite of death, nonfatal MI, stroke, or binary restenosis at eight months

Secondary Endpoints:

Freedom at day 30 and month 8 from major cardiac or cerebrovascular adverse events (composite of death, reinfarction, stroke, and repeat TVR)

Drug/Procedures Used:

Patients with STEMI at a single center were randomized open-label to treatment with a single high-dose bolus of tirofiban (25 µg/kg over three minutes) plus SES (n=87) or standard-dose abciximab plus BMS (n=88).

Concomitant Medications:

Aspirin (160-325 mg loading dose and 80-125 mg daily indefinitely), clopidogrel (300 mg loading dose and 75 mg daily for at least three months), and heparin (50 U/kg) to maintain activated clotting time of at least 200 seconds

Principal Findings:

Clinical and angiographic characteristics were well matched at baseline, with the left anterior descending artery the infarct-related artery in 45% of patients and single-vessel disease in 59%. Median door to balloon time was 70 minutes in the tirofiban + SES group and 67 minutes in the abciximab + BMS group. Post-percutaneous coronary intervention TIMI flow grade 3 was similar in both groups (96% and 93%, respectively, p=0.91), as was complete ST resolution (49% and 39%, respectively, p=0.55).

The primary endpoint of death, MI, stroke, or binary restenosis at eight months was lower in the tirofiban + SES group compared with the abciximab plus BMS group (19% vs. 50%, hazard ratio [HR] 0.33, p<0.001), driven primary by a reduction in binary restenosis (9% vs. 36%, p=0.002). Likewise, the composite of death, MI, stroke, or target vessel revascularization (TVR) was lower in the tirofiban + SES group compared with the abciximab + BMS group (18% vs. 32%, HR 0.53, p=0.04), driven primary by a reduction in TVR (7% vs. 20%, p=0.01). Diameter stenosis at follow-up angiography was smaller in the tirofiban plus SES group (15% vs. 42%, p<0.001), while late loss was smaller (-0.22 mm vs. +0.6 mm, p<0.001).

The safety profile was similiar between the groups, with no difference in major bleeding (1% for the tirofiban + SES group vs. 2% for the abciximab + DES group) or minor bleeding (8% vs. 9%). Any thrombocytopenia occurred more frequently in the abciximab + BMS group (9% vs. 1%, p=0.03), driven primarily by mild thrombocytopenia (7% vs. 1%, p=0.11), with no difference in severe thrombocytopenia (2% vs. 0%, p=0.49).

Interpretation:

Among patients with STEMI, treatment with a single, high-dose bolus of tirofiban + SES was associated with a reduction in the primary composite endpoint of death, MI, stroke, or binary restenosis at eight months compared with abciximab + BMS, driven by a reduction in binary restenosis.

The present study is one of the first randomized trials of drug-eluting stents in patients with STEMI. However, due to the randomization to two different therapies in each arm, no specific conclusions can be drawn on the individual therapies in the arms. One of the reasons for evaluating these two strategies was to determine if a more cost-effective regimen could be identified, since the use of tirofiban instead of abciximab would offset the added cost for stenting with sirolimus-eluting versus bare-metal stent. While the tirofiban + SES group was more effective, a formal cost-effectiveness study was not conducted as part of the trial.

References:

Valgimigli M, Percoco G, Malagutti P, et al. Tirofiban and sirolimus-eluting stent vs abciximab and bare-metal stent for acute myocardial infarction: a randomized trial. JAMA 2005;293:2109-17.

Clinical Topics: Arrhythmias and Clinical EP, Invasive Cardiovascular Angiography and Intervention, EP Basic Science

Keywords: Myocardial Infarction, Stroke, Follow-Up Studies, Platelet Aggregation Inhibitors, Drug-Eluting Stents, Sirolimus, Immunoglobulin Fab Fragments, Constriction, Pathologic, Tyrosine, Percutaneous Coronary Intervention, Metals, Chest Pain, Bundle-Branch Block, Thrombocytopenia


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