A Prospective, Randomized, Multicenter Trial to Assess an Everolimus-Eluting Coronary Stent System - PLATINUM

Contribution To Literature:

The PLATINUM trial showed that the platinum-chromium everolimus-eluting stent was noninferior to the cobalt-chromium everolimus-eluting stent in regard to target vessel failure.

Description:

The goal of this trial was to compare percutaneous coronary intervention (PCI) with a novel platinum-chromium everolimus-eluting stent versus a cobalt-chromium everolimus-eluting stent.

Study Design

  • Randomized
  • Parallel
  • Stratified

Patient Populations:

  • Patients at least 18 years of age undergoing elective PCI of a de novo native coronary lesion with a reference vessel diameter 2.5-4.25 mm and ≤24 mm in length.

    Number of enrollees: 1,530
    Duration of follow-up: 12 months, 5 years
    Mean patient age: 63 years
    Percentage female: 19%

Exclusions:

  • Acute or recent myocardial infarction
  • Left ventricular ejection fraction <30%
  • Prior or planned organ transplant
  • Recent or scheduled chemotherapy
  • Autoimmune disease or use of immunosuppressive therapy
  • Platelet count <100,000 cells/mm3 or >700,000 cells/mm3
  • White blood cell count <3000 cells/mm3
  • Liver disease
  • Renal disease (estimated creatinine clearance <50 ml/min or need for dialysis)
  • Gastrointestinal bleeding
  • Bleeding diathesis or coagulopathy
  • Use of warfarin
  • Refusal of blood transfusions
  • Stroke or transient ischemic attack within the last 6 months
  • Use of atherectomy, laser, or cutting balloon before stent placement
  • Planned PCI or coronary artery bypass grafting after the index procedure
  • Previous use of brachytherapy
  • Allergy to any component of the stent or any study medication
  • Limited life expectancy
  • Participation in another investigational study
  • Lesion in the following locations: ostial, bifurcation, chronic total occlusion, or bypass graft
  • Left main artery lesion
  • Excessive vessel tortuosity, angulation, or calcification

Primary Endpoints:

  • Target vessel failure at 12 months powered for noninferiority, defined as cardiac death related to the target vessel, myocardial infarction related to the target vessel, or ischemia-driven target lesion revascularization

Secondary Endpoints:

  • Stent thrombosis
  • Technical success, defined as successful delivery and deployment of the stent without balloon rupture or stent embolization
  • Clinical procedural success, defined as final lesion diameter <30% with TIMI 3 flow

Drug/Procedures Used:

After predilation of a de novo native lesion, patients were randomized to a platinum-chromium everolimus-eluting stent (n = 768) versus a cobalt-chromium everolimus-eluting stent (n = 762).

Concomitant Medications:

  • Aspirin 162-325 mg daily for 6 months, then 75-162 mg daily thereafter
  • Clopidogrel ≥300 mg prior to PCI and continued at 75 mg daily for 6 months in all patients, or 12 months if not high-risk for bleeding

Principal Findings:

Overall, 1,530 patients were randomized. In the platinum-chromium everolimus-eluting stent group, the mean age was 63 years, 19% were women, 25% had diabetes, and the mean reference vessel diameter/length was 2.6/12.5 mm, respectively.

Technical success was achieved in 99.4% of the platinum-chromium everolimus-eluting stent group and 98.8% of the cobalt-chromium everolimus-eluting stent group (p = 0.14). Clinical procedural success was achieved in 98.3% versus 98.2% (p = 0.83), and unplanned stenting was required in 5.9% versus 9.8% (p = 0.004), respectively.

At 12 months, the primary outcome of target vessel failure (per-protocol analysis) had occurred in 3.4% of the platinum-chromium everolimus-eluting stent group versus 2.9% of the cobalt-chromium everolimus-eluting stent group (p for noninferiority = 0.001). Results were similar according to intention to-treat analysis: 3.5% versus 3.2% (p for noninferiority = 0.0009), respectively.

At 12 months, all-cause death was 1.3% versus 1.2% (p = 0.85), cardiovascular death was 0.9% versus 0.7% (p = 0.58), myocardial infarction was 1.1% versus 1.8% (p = 0.25), target lesion revascularization was 1.9% versus 1.9% (p = 0.96), and definite or probable stent thrombosis was 0.4% versus 0.4% (p = 1.0), respectively, for platinum-chromium versus cobalt-chromium stents.

At 5 years, target vessel cardiac death, target vessel myocardial infarction, or ischemia driven target lesion revascularization was 9.1% for the platinum-chromium stent versus 9.3% for the cobalt-chromium stent (p = 0.87). Ischemia-driven target lesion revascularization was 5.3% vs. 6.2%, respectively for platinum versus cobalt-chromium stents (p = 0.43). Definite stent thrombosis was 0.8% vs. 0.7%, respectively for platinum versus cobalt-chromium stents (p = 0.79).

Interpretation:

Among patients undergoing elective PCI of a de novo native lesion, the novel platinum-chromium everolimus-eluting stent was noninferior to the cobalt-chromium everolimus-eluting stent in regard to target vessel failure. Target lesion revascularization occurred in approximately 2% of participants, whereas stent thrombosis occurred in 0.4% of participants (similar between the groups). Results were similar between the groups to 5 years of follow-up.

Purported advantages of this novel stent platform include enhanced trackability, vessel conformability, side-branch access, radiopacity, radial strength, and fracture resistance. Although this trial was not designed to demonstrate a difference in technical or clinical procedural success, these outcomes were similar between the groups. While potential performance advantages of this stent over existing technology may be marginal for simple lesions, this could become more evident in complex lesions. This will need to be addressed in future studies.

References:

Kelly CR, Teirstein PS, Meredith IT, et al. Long-term safety and efficacy of platinum chromium everolimus-eluting stents in coronary artery disease: 5-year results from the PLATINUM trial. JACC Cardiovasc Interv 2017;10:2392-400.

Stone GW, Teirstein PS, Meredith IT, et al., on behalf of the PLATINUM Trial Investigators. A Prospective, Randomized Evaluation of a Novel Everolimus-Eluting Coronary Stent: The PLATINUM (A Prospective, Randomized, Multicenter Trial to Assess an Everolimus-Eluting Coronary Stent System [PROMUS Element] for the Treatment of up to Two De Novo Coronary Artery Lesions) Trial. J Am Coll Cardiol 2011;57:1700-8.

Presented by Dr. Gregg Stone at ACC.11/i2 Summit, New Orleans, LA, April 4, 2011.

Clinical Topics: Cardiac Surgery, Invasive Cardiovascular Angiography and Intervention, Aortic Surgery

Keywords: Myocardial Infarction, Myocardial Revascularization, Percutaneous Coronary Intervention, Cobalt, Thrombosis, Immunosuppressive Agents, Chromium, Sirolimus, Diabetes Mellitus, Stents


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