Finding the Invasive Haemodynamic Threshold for Symptom Relief in Stable Angina

Finding the Invasive Haemodynamic Threshold for Symptom Relief in Stable Angina

ORBITA-FIRE is a randomised, double-blinded, placebo controlled experimental study that will identify the fractional flow reserve (FFR) and non-hyperemic pressure ratio (NHPR) thresholds that correlate with symptoms of angina for 58 patients measured invasively under experimental conditions.

Inclusion Criteria:

• Eligibility for percutaneous coronary intervention (PCI) due to angina or angina-equivalent symptoms on exertion

• Anatomical evidence of significant single-vessel coronary stenosis defined by either:

  • ≥70% stenosis on invasive coronary angiography (ICA)
  • Severe stenosis on CT coronary angiography (CTCA)

• Physiological evidence of ischaemia with a positive test on at least one of the following:

  • Stress echocardiography
  • Cardiac magnetic resonance perfusion
  • Myocardial perfusion scintigraphy
  • Invasive metrics of coronary physiology

Exclusion Criteria:

• Age <18 years
• Recent acute coronary syndrome
• Previous coronary artery by-pass graft
• Significant left main stem disease
• Multivessel disease (defined as >50% angiographic stenosis in other vessels)
• Chronic total occlusion in the target artery
• Moderate to severe valvular disease
• Moderate to severe left ventricular impairment
• Chronotropic incompetence with a pacemaker
• Contraindication to PCI or a drug-eluting stents
• Contraindication to antiplatelet therapy
• Contraindication to adenosine
• Moderate to severe respiratory disease
• Physical inability to exercise
• Pregnant
• Inability to consent