Heparin-Coated Stents in Small Coronary Arteries - COAST

Description:

The goal of the Heparin-Coated Stents in Small Coronary Arteries (COAST) trial was to compare the outcomes among conventional angioplasty balloons, bare metal stents, and stents with heparin coating deployed in small coronary arteries.

Study Design

Study Design:

Patients Enrolled: 588
Mean Follow Up: Six months
Mean Patient Age: Mean age 61 years
Female: 26%

Patient Populations:

Stable or unstable angina presenting stenoses in native coronary arteries ranging from 2.0 mm to 2.6 mm in diameter.

Exclusions:

Acute or evolving MI within 24 hours, severe heart failure (left ventricular ejection fraction <30%), or contraindication to aspirin, ticlopidine, or clopidogrel.

Primary Endpoints:

MLD at six months.

Secondary Endpoints:

Procedural success rates and the incidence of death, myocardial infarction (MI), thrombotic events, angiographic restenosis (>50% diameter stenosis), target vessel revascularization, and event-free survival at the end of hospitalization at 30 and 250 days.

Drug/Procedures Used:

The COAST trial randomized 588 patients from 21 European centers with stenoses in 2.0 mm to 2.6 mm diameter vessels to treatment with either conventional percutaneous transluminal coronary balloon angioplasty (PTCA; n=195), a noncoated stent (n=196), or a heparin-coated stent (n=197).

Concomitant Medications:

All patients received aspirin and heparin (10,000 units). Patients in the two stent groups also received standard doses of ticlopidine for four weeks following stent placement. Use of glycoprotein IIb/IIIa blockers was discouraged.

Principal Findings:

Multivessel disease was present in 80% of patients at baseline. The crossover rate from PTCA to stenting was 27%. At the six-month follow-up, there were 195 clinically evaluable and 155 angiographically evaluable patients in the PTCA group; 196 and 157 in the noncoated stent group, respectively; and 197 and 155 in the heparin-coated stent group, respectively. The primary end point of minimal lumen diameter (MLD) at six months was smaller in the PTCA arm (1.34 mm vs. 1.47 mm in the bare stent arm and 1.45 mm in the coated arm, three-way p=0.049). There was no difference in MLD between the bare and coated stent arms. Restenosis was greater in the PTCA arm (42% vs. 36% in the bare stent arm vs. 38% in the coated stent arm, p=0.038). Late loss did not differ between the three arms (0.73 mm vs. 0.69 mm vs. 0.76 mm, respectively, p=NS). There was no difference in adverse events, death, or event-free survival between treatment groups at any of the time points. Event-free survival at 250 days was 84.6% (angioplasty), 88.3% (bare stent), and 88.3% (heparin-coated stent, log-rank p=0.39). The rate of thrombotic events was 1.0% in the PTCA arm (n=2), 0.5% in the bare stent arm (n=1), and 0.5% in the heparin-coated stent arm (n=1; p=NS).

Interpretation:

Among patients with vessels 2.0 mm to 2.6 mm in diameter, the MLD at six months was smaller in the conventional PTCA arm compared with the stent arms, but there was no difference between the bare and heparin-coated stent arms. No difference in clinical outcomes was observed among patients treated with either conventional balloon PTCA, bare stents, or heparin-coated stents. The authors speculated that the heparin-coated stents would reduce thrombotic events; however, the thrombotic event rate was very low in both stent arms (0.5%, n=1 each), possibly due to the adjunctive use of aspirin and ticlopidine or clopidogrel following the procedure. As many other trials have shown, treatment with stenting (bare or heparin-coated) was associated with consistently improved angiographic outcomes at six months compared with conventional balloon angioplasty; however, no additional benefit was conferred with use of a heparin-coated stent over a bare stent.

References:

Haude M, Konorza TF, Kalnins U, et al. Heparin-coated stent placement for the treatment of stenoses in small coronary arteries of symptomatic patients. Circulation. 2003;107:1265-70.

Clinical Topics: Anticoagulation Management, Invasive Cardiovascular Angiography and Intervention

Keywords: Drug-Eluting Stents, Heparin, Disease-Free Survival, Coronary Disease, Ticlopidine, Constriction, Pathologic, Coronary Vessels, Angioplasty, Balloon, Coronary, Stents


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