A Bioresorbable Everolimus-Eluting Scaffold Versus a Metallic Everolimus-Eluting Stent III - ABSORB III

Description:

The goal of the trial was to assess the safety and efficacy of Absorb BVS, an everolimus-eluting bioresorbable vascular scaffold, compared with Xience, a cobalt–chromium drug-eluting stent (DES) at 1 year.

Contribution to the Literature: The ABSORB III trial showed that Absorb BVS is noninferior to the cobalt–chromium-based Xience DES at 1 year for cardiovascular outcomes in noncomplex coronary lesions, with lower acute procedural success.

Study Design

Patients were randomized in a 2:1 ratio to either Absorb BVS (n = 1,322) or cobalt–chromium-based Xience DES (n = 686).

  • Total number of enrollees: 2,008
  • Duration of follow-up: 1 year
  • Mean patient age: 63.6 years
  • Percentage female: 30%

Other salient features/characteristics:

  • Diabetes: 32%
  • Prior percutaneous coronary intervention (PCI): 38%
  • Stable angina: 59%
  • Single-vessel disease: 68%
  • Lesion length: 13 mm
  • Reference vessel diameter (RVD): 2.65 mm
  • Post-dilatation required for BVS vs. Xience: 65.5% vs. 51.2%, p < 0.001
  • Intravascular imaging: 11%

Inclusion criteria:

  • >18 years old
  • Evidence of myocardial ischemia (stable/unstable/post-infarction angina or silent ischemia)
  • No elevation of creatine kinase-myocardial band
  • One or two de novo target lesions in up to two native coronary arteries (maximum one lesion per artery)
  • Diameter stenosis ≥50% and <100% with Thrombolysis in Myocardial Infarction (TIMI) flow ≥1
    • If <70%, abnormal functional test (including fractional flow reserve ≤0.80), unstable angina, or post-infarct angina
  • RVD ≥2.50 mm and ≤3.75 mm (site-determined)
  • Lesion length ≤24 mm (site-determined)

Exclusion criteria:

  • Known hypersensitivity or contraindication to aspirin, both heparin and bivalirudin, antiplatelet medication specified for use in the study (clopidogrel and prasugrel and ticlopidine, inclusive), everolimus, poly (L-lactide), poly (DL-lactide), cobalt, chromium, nickel, tungsten, acrylic, and fluoro polymers or contrast sensitivity that cannot be adequately premedicated
  • Subject has a known diagnosis of acute myocardial infarction (AMI) at any time preceding the index procedure and relevant cardiac enzymes have not returned within normal limits at the time of procedure
  • Evidence of ongoing AMI in electrocardiogram prior to procedure
  • Subject has current unstable arrhythmias
  • Left ventricular ejection fraction <30%
  • Prior PCI in target vessel within 12 months
  • Need for staged PCI within 30 days
  • Subject has received a heart transplant or any other organ transplant or is on a waiting list for any organ transplant
  • Subject is receiving immunosuppressant therapy and/or has known immunosuppressive or autoimmune disease
  • Subject has a platelet count <100,000 cells/mm3 or >700,000 cells/mm3, a white blood cell count of <3,000 cells/mm3, or documented or suspected liver disease
  • Known renal insufficiency (e.g., estimated glomerular filtration rate <60 ml/kg/1.73 m2 or serum creatinine level of >2.5 mg/dl, or subject on dialysis)
  • History of bleeding diathesis or coagulopathy or will refuse blood transfusions
  • Subject had a cerebrovascular accident or transient ischemic neurological attack within the past 6 months

Angiographic exclusion criteria:

  • Target lesion which prevents adequate (residual stenosis at target lesion/s is ≤40% by visual assessment) coronary predilatation
  • Target lesion in left main trunk
  • Aorto-ostial target lesion (within 3 mm of the aorta junction)
  • Target lesion located within 3 mm of the origin of the left anterior descending or left circumflex artery
  • Target lesion involving a bifurcation lesion with side branch ≥2 mm in diameter, or with a side branch <2 mm in diameter requiring guidewire protection or dilatation
  • Total occlusion (TIMI flow 0), prior to wire crossing
  • Excessive tortuosity (≥2, 45° angles), or extreme angulation (≥90°) proximal to or within the target lesion
  • Heavy calcification proximal to or within the target lesion
  • Target lesion located within an arterial or saphenous vein graft or distal to any arterial or saphenous vein graft
  • Vessel has been previously treated with a stent at any time prior to the index procedure such that the Absorb BVS or Xience stent would need to cross the stent to reach the target lesion

Principal Findings:

The primary outcome, target-lesion failure (cardiac death, target vessel MI [TV-MI], ischemia-driven target-vessel revascularization [ID-TLR]) for BVS vs. Xience, was 7.8% vs. 6.1% (p for noninferiority = 0.007, p for superiority = 0.16)

  • Cardiac death: 0.6% vs. 0.1%, p = 0.29
  • TV-MI: 6.0% vs. 4.6%, p = 0.18
  • ID-TLR: 3.0% vs. 2.5%, p = 0.5

Secondary outcomes:

  • Acute success: 94.3% vs. 99.3%, p < 0.0001
  • Immediately post-procedure quantitative coronary angiography: In-device minimum lumen diameter: 2.37 mm vs. 2.49 mm, p < 0.0001; acute gain: 1.45 vs. 1.59 mm, p < 0.0001
  • Device thrombosis: 1.5% vs. 0.7%, p = 0.13
  • All revascularization: 9.1% vs. 8.1%, p = 0.5

Interpretation:

The results of this trial indicate that Absorb BVS is noninferior to the cobalt–chromium-based Xience DES at 1 year for cardiovascular outcomes in noncomplex coronary lesions. However, acute device and post-procedure success were lower, and unfavorable trends were also observed for device thrombosis and target-vessel failure in smaller vessels (RVD <2.25 mm) with BVS.

ABSORB III is the pivotal trial towards US premarket approval of Absorb BVS, and adds to the growing body of literature with the stent. Longer-term data are awaited to see if Absorb BVS perform is better than Xience beyond 1 year, as bioabsorbable platforms have a theoretical advantage over durable polymer platforms beyond this time frame.

References:

Ellis SG, Kereiakes DJ, Metzger C, et al., on behalf of the ABSORB III Investigators. Everolimus-Eluting Bioresorbable Scaffolds for Coronary Artery Disease. N Engl J Med 2015;Oct 12:[Epub ahead of print].

Presented by Dr. Dean J. Kereiakes at the Transcatheter Cardiovascular Therapeutics meeting (TCT 2015), San Francisco, CA, October 12, 2015.

Clinical Topics: Cardiac Surgery, Invasive Cardiovascular Angiography and Intervention, Noninvasive Imaging, Stable Ischemic Heart Disease, Aortic Surgery, Cardiac Surgery and SIHD, Interventions and Coronary Artery Disease, Interventions and Imaging, Angiography, Nuclear Imaging, Chronic Angina

Keywords: Angina Pectoris, Angina, Stable, Angina, Unstable, Chromium, Cobalt, Coronary Angiography, Coronary Artery Disease, Drug-Eluting Stents, Myocardial Infarction, Myocardial Ischemia, Myocardial Revascularization, Percutaneous Coronary Intervention, Stents, Thrombosis, Transcatheter Cardiovascular Therapeutics


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