Conventional Stenting Versus Direct Stenting in (Un)stable Angina Pectoris - CONVERTIBLE

Description:

The goal of the trial was to evaluate conventional stenting with direct stenting among patients undergoing percutaneous coronary intervention for single de novo lesions.

Study Design

Study Design:

Patients Enrolled: 202
Mean Follow Up: 6 months
Mean Patient Age: Mean age 63 years
Female: 26
Mean Ejection Fraction: Mean 64% at baseline

Patient Populations:

Age ≥18 years with stable or unstable angina or a positive functional study with a planned PCI procedure of a single de novo lesion ≤13 mm long in a native coronary artery

Exclusions:

Left ventricular ejection fraction <30%, acute MI in prior 3 days, platelet count <100,000 or >700,000 cells/mm3, white blood count of <3000 cells/mm3, presence of a moderately to severely tortuous vessel, presence of extremely calcified or thrombotic lesion, side branch >2.5 mm that would be covered by the stent, and ostial lesions within 2 mm of the origin.

Primary Endpoints:

Minimum lumen diameter immediately following stent placement.

Secondary Endpoints:

Procedural success rate (final in-stent stenosis at the target lesion ≤15%); major adverse cardiac events (MACE) free survival at 30 days and 6 months; IVUS measurements; FFR measurements; QCA measurements by core laboratory analysis; 6 months angiographic restenosis rate; and incidence of stent thrombosis, stent delivery failure, major dissections (type ≥C), and failure to achieve direct stenting (cross-over)

Drug/Procedures Used:

Patients with a single, de novo lesion in a native vessel were randomized to conventional stenting with pre-dilatation (n=101) or direct stenting (n=101). All patients were to receive the Medtronic BeStent2. Patients underwent repeat angiography at 6 months. A subset of patients also underwent follow-up IVUS.

Concomitant Medications:

Aspirin indefinitely (≥75 mg/day) and either ticlopidine (500 mg load and 250 mg twice daily) or clopidogrel (300 mg loadand 75 mg/day) for 14-28 days post-procedure.

Principal Findings:

Seven patients in the direct stent crossed over to pre-dilatation, with the remaining 94% undergoing direct stenting. Baseline clinical and angiographic characteristics were similar in the two treatment groups. The primary endpoint of post-procedural minimum lumen diameter did not differ by treatment group (2.79 mm for direct stent vs 2.76 for pre-dilatation, meeting the one-sided p-value for non-equivalence, p=0.0003). By IVUS, there was no difference by treatment group in minimum stent area (7.89 mm2 for direct stent vs 8.07 mm2 for pre-dilatation, p=0.69) or fractional flow reserve (0.92 in each group, p=0.97).

At 6 month angiographic follow-up, there was no difference in minimum lumen diameter (2.09 mm for direct stenting vs 2.10 mm for pre-dilatation, p=0.92), percent diameter stenosis (26.3% vs 27.2%, p=0.89) or binary restenosis (7.4% vs 6.8%, p=0.87). Major adverse cardiac events at 6 months occurred in 9% of the direct stent group and 11% of the pre-dilatation group (p=0.93).

Interpretation:

Among patients undergoing percutaneous coronary intervention for single de novo lesions, use of direct stenting was associated with similar post-procedure minimum lumen diameter compared with pre-dilatation.

While the present study demonstrated non-inferiority with direct stenting for single, de novo lesions, patients with thrombotic or calcified lesions were excluded. Results of the present trial may not be applicable to more complex lesions. It should be noted that the present trial used non-drug-eluting stents but that the 6 month restenosis rate was rather low in both treatment groups at only 7%.

References:

Wijns W, et al. Angiographic, intravascular ultrasound, and fractional flow reserve evaluation of direct stenting vs.conventional stenting using BeStent2 in a multicentre randomized trial. Eur Heart J. 2005 May 11; [Epub ahead of print]

Keywords: Drug-Eluting Stents, Dilatation, Coronary Disease, Constriction, Pathologic, Stents, Percutaneous Coronary Intervention


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