Scandinavian Organization for Randomized Trials With Clinical Outcome IX - SORT OUT IX

Contribution To Literature:

The SORT OUT IX trial showed that BioFreedom DCS did not meet criteria for noninferiority for MACE at 1 year compared with the Orsiro DES in an all-comers population with CAD.


The goal of this trial was to compare the safety and efficacy of BioFreedom drug-coated stent (DCS) compared with biodegradable polymer sirolimus-eluting stent (SES) in reducing clinical outcomes in a real-world population of patients presenting with coronary artery disease (CAD).

Study Design

Eligible patients were randomized in a 1:1 fashion to either BioFreedom (biolimus A9-coated DCS) or biodegradable polymer SES (Orsiro).

  • Total number of enrollees: 3,151
  • Duration of follow-up: 1 year
  • Mean patient age: 66.3 years
  • Percentage female: 23%

Inclusion criteria:

  • ≥18 years old
  • Evidence of CAD with >50% diameter stenosis
  • Requires treatment with a drug-eluting stent (DES)

Exclusion criteria:

  • Allergy to aspirin, clopidogrel, ticagrelor, prasugrel, sirolimus, or biolimus
  • Participation in another randomized stent trial
  • Inability to provide written informed consent
  • Life expectancy of <1 year

Other salient features/characteristics:

  • Secondary prevention cohort: 70.7%
  • Previous percutaneous coronary intervention (PCI): 21%
  • Indication for PCI: ST-segment elevation myocardial infarction (STEMI) (24%), NSTEMI (29%)
  • Number of lesions per patient: 1.3

Principal Findings:

The primary outcome, major adverse cardiac events (MACE; cardiac death, MI, target lesion revascularization [TLR]) at 1 year for BioFreedom DCS vs. Orsiro DES, was 5.0% vs. 3.7% (hazard ratio 1.34, 95% confidence interval 0.96-1.89; p for noninferiority = 0.14, p for superiority = 0.09).

  • Cardiac mortality: 1% vs. 1.8% (p = 0.06)
  • MI not related to other lesion: 1.7% vs. 1.6% (p = 0.99)
  • TLR: 3.5% vs. 1.3% (p < 0.0001)

Secondary outcomes for BioFreedom DCS vs. Orsiro DES:

  • TLR at 30 days: 0.4% vs. 0.6% (p = 0.32)
  • Definite or probable stent thrombosis at 12 months: 1.0% vs. 1.1% (p = 0.73)


The results of this trial indicate that BioFreedom DCS did not meet criteria for noninferiority for MACE at 1 year compared with the Orsiro DES in an all-comers population with CAD. This was primarily driven by a higher risk of TLR, likely due the difference in stent thickness (120 micrometers for Biofreedom vs. 60-80 micrometers for Orsiro), and faster release of drug (1 vs. 3 months).

In the LEADERS FREE and LEADERS FREE II trials, the BioFreedom DCS was superior to bare-metal stent (BMS), suggesting that its efficacy was likely in between BMS and contemporary DES. In theory, the BioFreedom DCS could be used with a shorter duration of dual antiplatelet therapy, but this was not tested in this trial. It is currently not approved by the United States Food and Drug Administration (FDA).


Jensen LO, Maeng M, Raungaard B, et al. Randomised Comparison of the Polymer-Free Biolimus-Coated BioFreedom Stent With the Ultrathin Strut Biodegradable Polymer Sirolimus-Eluting Orsiro Stent in an All-Comers Population Treated With Percutaneous Coronary Intervention: The SORT OUT IX Trial. Circulation 2020;May 21:[Epub ahead of print].

Clinical Topics: Acute Coronary Syndromes, Cardiac Surgery, Invasive Cardiovascular Angiography and Intervention, Prevention, Atherosclerotic Disease (CAD/PAD), Aortic Surgery, Cardiac Surgery and Arrhythmias, Interventions and ACS, Interventions and Coronary Artery Disease

Keywords: Acute Coronary Syndrome, Constriction, Pathologic, Coronary Artery Disease, Drug-Eluting Stents, Myocardial Infarction, Myocardial Revascularization, Percutaneous Coronary Intervention, Platelet Aggregation Inhibitors, Secondary Prevention, Sirolimus, Stents, Thrombosis

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