Percutaneous coronary intervention versus medical therapy in patients with angina and grey-zone fractional flow reserve values: a randomised clinical trial

Heart. 2020 May;106(10):758-764. doi: 10.1136/heartjnl-2019-316075. Epub 2020 Feb 29.


Introduction: There is conflicting evidence regarding the benefits of percutaneous coronary intervention (PCI) in patients with grey zone fractional flow reserve (GZFFR artery) values (0.75-0.80). The prevalence of ischaemia is unknown. We wished to define the prevalence of ischaemia in GZFFR artery and assess whether PCI is superior to optimal medical therapy (OMT) for angina control.

Methods: We enrolled 104 patients with angina with 1:1 randomisation to PCI or OMT. The artery was interrogated with a Doppler flow/pressure wire. Patients underwent Magnetic Resonance Imaging (MRI) with follow-up at 3 and 12 months. The primary outcome was angina status at 3 months using the Seattle Angina Questionnaire (SAQ).

Results: 104 patients (age 60±9 years), 79 (76%) males and 79 (76%) Left Anterior Descending (LAD) stenoses were randomised. Coronary physiology and SAQ were similar. Of 98 patients with stress perfusion MRI data, 17 (17%) had abnormal perfusion (≥2 segments with ≥25% ischaemia or ≥1 segment with ≥50% ischaemia) in the target GZFFR artery. Of 89 patients with invasive physiology data, 26 (28%) had coronary flow velocity reserve <2.0 in the target GZFFR artery. After 3 months of follow-up, compared with patients treated with OMT only, patients treated by PCI and OMT had greater improvements in SAQ angina frequency (21 (28) vs 10 (23); p=0.026) and quality of life (24 (26) vs 11 (24); p=0.008) though these differences were no longer significant at 12 months.

Conclusions: Non-invasive evidence of major ischaemia is uncommon in patients with GZFFR artery. Compared with OMT alone, patients randomised to undergo PCI reported improved symptoms after 3 months but these differences were no longer significant after 12 months.

Trial registration number: NCT02425969.

Keywords: combined pressure and doppler flow coronary wire; fractional flow reserve; percutaneous coronary intervention; stress perfusion MRI.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Angina, Stable* / diagnosis
  • Angina, Stable* / physiopathology
  • Angina, Stable* / therapy
  • Cardiovascular Agents / therapeutic use*
  • Coronary Angiography / methods
  • Coronary Vessels* / diagnostic imaging
  • Coronary Vessels* / physiopathology
  • Echocardiography, Doppler, Color / methods*
  • Female
  • Fractional Flow Reserve, Myocardial / physiology*
  • Humans
  • Magnetic Resonance Imaging, Cine / methods*
  • Male
  • Middle Aged
  • Myocardial Perfusion Imaging / methods*
  • Outcome Assessment, Health Care
  • Percutaneous Coronary Intervention* / adverse effects
  • Percutaneous Coronary Intervention* / methods
  • Symptom Assessment / methods


  • Cardiovascular Agents

Associated data