Direct Stenting Using the Sirolimus-Eluting Stent - DIRECT

Description:

The goal of the trial was to evaluate the use of direct stenting compared with predilatation in patients receiving sirolimus-eluting stents for treatment of single, de novo lesions.

Hypothesis:

Direct stenting will lead to improved outcomes due to reduced arterial injury, the avoidance of abrupt vessel closure, and reduced margin restenosis and procedural time.

Study Design

Patients Enrolled: 225
Mean Follow Up: Eight months
Mean Patient Age: Mean age 62 years
Female: 72

Patient Populations:

Enrollment inclusion criteria matched those of the SIRIUS trial: de novo native coronary lesions requiring single-vessel treatment of lesions 2.5-3.5 mm in diameter and 15-30 mm in length.

Exclusions:

Enrollment exclusion criteria matched those of the SIRIUS trial: recent MI (<24 hours); unprotected left main disease; ostial location; total occlusion (TIMI 0 flow); angiographic evidence of thrombus; calcified lesion that cannot be predilated; left ventricular ejection fraction <25%; impaired renal function; pretreatment with devices other than balloon angioplasty; allergy to aspirin, clopidogrel, or ticlopidine; or prior or planned intervention within 30 days.

Primary Endpoints:

In-lesion late loss at eight months

Secondary Endpoints:

MACE, angiographic binary restenosis, delivery strategy success, and procedure time at eight months

Drug/Procedures Used:

Patients were enrolled at 16 US sites from April-June 2003 and received sirolimus-eluting stents using direct stenting. The trial compared patients in the present, direct stenting study with historical controls of patients in the sirolimus-eluting stent arm of the SIRIUS trial (n=533), which had a mandatory predilatation stent delivery strategy.

Principal Findings:

Device and procedural success were similar in the direct stent group versus the predilatation group (99.6% vs. 97.9%, p=0.12 and 99.1% vs. 97.4%, p=0.17, respectively). Glycoprotein (GP) IIb/IIIa inhibitors were used more frequently in the DIRECT patients compared with the SIRIUS predilatation patients (64% vs. 58%, p=0.015).

Other changes in practice pattern include higher maximum device pressures (15.5 vs. 14.0 atm, p<0.001) and longer stent lengths (22.6 vs. 21.4 mm, p<0.05) in DIRECT. Procedural time was shorter in the direct stent group (median 33 minutes vs. 45 minutes, p<0.01).

Direct stenting was successful in 86% of patients in the DIRECT study. There was no difference in 30-day major adverse cardiac events (MACE) (0.9% vs. 2.6%, p=0.23), myocardial infarction (MI) (0.9% vs. 2.4%, p=0.27), and target vessel failure (0.9% vs. 2.8%, p=0.20). There was also no difference in six-month MACE (2.2% vs. 4.9%, p=0.21). Stent thrombosis occurred by six months in 0.4% of direct stent patients versus 0.2% of predilatation patients (p=0.44).

There was no difference in the primary endpoint of eight-month late loss in-stent (0.18 mm vs. 0.17 mm, p=NS) or in-lesion (0.21 vs. 0.24, p=NS). Binary restenosis rates were also similar in both groups (3.6% vs. 3.2% for in-stent, p=0.80; 6.0% vs. 9.1% for in-lesion, p=0.30). Similar results were observed in the subgroup of patients with small, medium, and large vessels, as well as diabetics.

Interpretation:

Among patients receiving sirolimus-eluting stents for treatment of single, de novo lesions, there was no difference in procedure success, MACE at six months, or late loss at eight months for direct stenting compared with historical controls of predilatation.

Other trials such as E-SIRIUS have reported on the subgroup of patients undergoing direct stenting versus predilatation with sirolimus-eluting stent, but the number of patients was relatively small (<100). While provoking, the trial has several limitations, most noteably the nonrandomized design and the use of historical controls, which differed in several important practice patterns compared with the current trial population, such as a higher use of GP IIb/IIIa inhibitors, longer stent length, and higher maximum device pressure.

References:

Presented by Dr. Jeffrey W. Moses, at the American College of Cardiology Annual Scientific Session, March 2004.

Moses JW, Weisz G, Mishkel G, et al. The SIRIUS-DIRECT trial: a multi-center study of direct stenting using the sirolimus-eluting stent in patients with de novo native coronary artery lesions. Catheter Cardiovasc Interv. 2007 Oct 1;70(4):505-12.

Clinical Topics: Heart Failure and Cardiomyopathies, Invasive Cardiovascular Angiography and Intervention, Atherosclerotic Disease (CAD/PAD), Heart Failure and Cardiac Biomarkers, Interventions and Coronary Artery Disease

Keywords: Coronary Artery Disease, Myocardial Infarction, Pyridinolcarbamate, Thrombosis, Drug-Eluting Stents, Sirolimus, Diabetes Mellitus, Platelet Membrane Glycoprotein IIb


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