Comparison of BuMA eG Based BioDegradable Polymer Stent With EXCEL Biodegradable Polymer Sirolimus-eluting Stent in “Real-World” Practice - PANDA III

Description:

The goal of the trial was to assess the safety and efficacy of a novel sirolimus-eluting (SES) bioabsorbable stent (BuMA) compared with an existing sirolimus-eluting bioabsorbable stent (Excel).

Contribution to the Literature: The PANDA III trial showed that a novel bioabsorbable SES (BuMA) is noninferior to Excel bioabsorbable SES for clinical outcomes at 1 year.

Study Design

Chinese patients with coronary artery disease (CAD) were randomized in a 1:1 fashion to either BuMA (n = 1,175) or Excel (n = 1,175).

  • Total number of enrollees: 2,338
  • Duration of follow-up: 1 year
  • Mean patient age: 61 years
  • Percentage female: 29%

Other salient features/characteristics:

  • Percentage smokers: 37%
  • Percentage with diabetes: 24%
  • Prior percutaneous coronary intervention (PCI): 12%
  • Percentage with stable angina: 15%, unstable angina: 50%
  • SYNTAX score: 15.8
  • Lesion number (mean): 1.3, number of stents: 1.7
  • Total stent length per patient (mean): 31.3 mm
  • Reference vessel diameter (mean): 2.75 mm

Inclusion criteria:

  • Age ≥18 years
  • Symptomatic CAD or silent ischemia, or acute coronary syndrome (ACS), and qualifies for PCI
  • ≥1 coronary artery stenosis of ≥50% with visually estimated reference vessel diameter ≥2.5 mm and ≤4.0 mm

Exclusion criteria:

  • Known allergy to contrast and/or device or study medications (PLA, PLGA, sirolimus, aspirin, clopidogrel, stainless steel, cobalt chromium alloy, etc.)
  • Planned surgery within 6 months after the index procedure
  • Participation in another investigational clinical trial that has not reached its primary endpoint

Principal Findings:

The primary outcome, target-lesion failure at 1 year, for BuMA vs. Excel, was 6.4% vs. 6.4%, p for noninferiority = 0.0003, p for superiority = 0.95.

  • Cardiovascular death: 1.2% vs. 1.3%, p = 0.85
  • Target-vessel myocardial infarction: 4.3% vs. 4.9%, p = 0.48
  • Ischemia-driven target-lesion revascularization: 1.9% vs. 1.2%, p = 0.18

Secondary outcomes:

  • Procedure success: 95.1% vs. 94.7%
  • Any revasccularization: 4.5% vs. 2.9%, p = 0.05
  • Definite/probable stent thrombosis: 0.5% vs. 1.3%, p = 0.048

Interpretation:

The results of this trial indicate that a novel bioabsorbable SES is noninferior to Excel bioabsorbable SES for clinical outcomes at 1 year. There was a lower risk of stent thrombosis at 1 year with the novel stent, but a higher risk of all-cause revascularization (numerically higher ischemia-driven target-lesion revascularization as well). Longer-term follow-up data are awaited.

Both the stents in this study are bioabsorbable SES stents. The BuMA stent is PLGA-based and has an electro-grafting base layer between the polymer and stent strut securing adhesion of the PLGA coating. Sirolimus is completely eluted within 30 days, and the PLGA polymer is completely absorbed within 3 months. On the other hand, the Excel stent is PLA-based. It elutes sirolimus completely within 180 days, and the PLA polymer is completely absorbed within 6-9 months. Neither of these stents is currently available in the United States, but adds to the growing body of literature with bioabsorbable stent platforms.

References:

Xu B, Gao R, Yang Y, et al. Biodegradable Polymer-Based Sirolimus-Eluting Stents With Differing Elution and Absorption Kinetics: The PANDA III Trial. J Am Coll Cardiol 2016;67:2249-58.

Presented by Dr. Bo Xu at the Transcatheter Cardiovascular Therapeutics meeting (TCT 2015), San Francisco, CA, October 14, 2015.

Keywords: Acute Coronary Syndrome, Angina Pectoris, Chromium Alloys, Coronary Artery Disease, Coronary Stenosis, Myocardial Infarction, Myocardial Ischemia, Percutaneous Coronary Intervention, Polymers, Sirolimus, Stainless Steel, Stents, Thrombosis, Ticlopidine, Transcatheter Cardiovascular Therapeutics


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