International Post-PCI FFR Extended Registry
Condition: Coronary Disease
MeSH terms: Coronary Disease
Study type: Observational

Summary: 
      Percutaneous coronary intervention (PCI) is a standard treatment strategy for coronary artery
      disease (CAD). With the presence of myocardial ischemia, PCI reduces the risks of death,
      myocardial infarction (MI), and revascularization compared to medical therapy. However, the
      risk of future clinical events remains high, and about 10% of patients experienced further
      cardiovascular events after PCI. Several factors are associated with these poor outcomes.
      Well-known patient-related risk factors are diabetes mellitus, chronic kidney disease, left
      ventricular dysfunction, previous MI, and presentation with acute coronary syndrome.
      Procedure-related factors, such as stent under expansion, malposition, edge dissection, the
      number of the used stent, and total stent length, are also related to poor prognosis after
      PCI. Recent studies reported that fractional flow reserve (FFR) after coronary stenting, or
      post-PCI FFR, was associated with future clinical outcomes after PCI, and low post-PCI FFR
      value was associated with procedural factors. However, optimal cut-off values of post-PCI FFR
      ranged widely, from 0.86 to 0.96, and some studies reported the limited prognostic value of
      post-PCI FFR. This might result from differences in study populations, the definition of
      outcomes, type of stent used, and distribution of included vessels among previous studies.
      Previously, the investigators incorporated previous data into the International Post-PCI FFR
      registry and demonstrated the prognostic value of post-PCI FFR using the machine learning
      technique. However, the results were based on the two years follow-up of patients after PCI,
      and the prognostic value of post-PCI FFR in long-term outcomes is still uncertain. Therefore,
      the investigators planned to extend the International Post-PCI FFR registry to define the
      long-term prognostic implication of post-PCI FFR.
    

Detailed description: 
      The investigators planned to extend the International Post-PCI FFR registry (NCT04684043) to
      explore the long-term prognostic value of post-PCI FFR. The International Post-PCI FFR
      registry (NCT04684043) already included the 2,200 patients who underwent PCI and measured
      post-PCI FFR between June 2011 and May 2018. As the clinical, angiographic, and physiologic
      data are already collected in the International Post PCI FFR registry, the investigators will
      further collect the most recent clinical outcome data until 2021.5 and incorporate them into
      the International Post-PCI FFR Extended registry. As the current study will evaluate clinical
      outcomes at 5 years, 2,128 patients who underwent PCI and measured post-PCI FFR between June
      2011 and Nov 2016 will be included and studied. The investigators will request further
      clinical outcome data from 10 hospitals that provided the data for the International Post-PCI
      FFR registry before.

      A standardized form of a spreadsheet, including standardized definitions of variables, was
      used to collect the individual patient data from the principal investigators of each
      qualified registry. Patient clinical, angiographic, and physiologic data at the time of index
      PCI were recorded and already collected at Seoul National University Hospital. As clinical
      outcome data of 2 years of follow-up after index PCI are already collected in the
      International Post-PCI FFR registry (NCT04684043), clinical outcome data after 2 years of
      index PCI will be collected by medical records until 2021.5 of each hospital. All submitted
      data were double-checked by a central monitoring team in Seoul National University Hospital.
      All patients' identifying numbers are anonymized as "Subject_No" and the investigators will
      request the patients' clinical outcome data using these anonymized identifying numbers of the
      patients. Also, the investigators will share collected data with collaborators, using these
      numbers.
    

Intervention name(s): Percutaneous coronary intervention
Intervention type(s): Device
Intervention description(s): PCI was performed using drug-eluting stents
Observational model: Cohort
Time perspective: Retrospective
Sampling method: Non-Probability Sample
Study population: 
        Patients who were diagnosed as obstructive coronary artery disease and treated by DES and
        measured post PCI FFR after PCI.
      
Keywords: fractional flow reserve; percutaneous coronary intervention; drug-eluting stent; coronary atherosclerosis