title: Impact of right atrial pressure on decision-making using fractional flow reserve (FFR) in elective percutaneous intervention.
abstract: BACKGROUND
  We undertook a prospective study to assess the impact of routine incorporation of right atrial pressure into the calculation of FFR in a real world elective PCI cohort.
  
  
  METHODS
  42 patients with stenoses in 2 separate epicardial vessels at coronary angiography were studied. Using a temperature and pressure sensing guidewire (TPSG) FFR and FFRRAP were performed in the target vessel pre and post PCI and in a non-target vessel. FFR was defined as Pd/Pa, FFRRAP as Pd-Pv/Pa-Pv where Pv was right atrial pressure and Pd/Pa were the hyperemic distal and proximal arterial pressures respectively.
  
  
  RESULTS
  Mean RAP was 9.1 ± 0.7 mmHg. Mean FFR was significantly lower when RAP was included in the calculation (FFRRAP 0.77 ± 0.19 vs. FFR 0.80 ± 0.16, p<0.001). In the target vessel pre PCI, incorporating RAP into the calculation of FFR resulted in a significant difference in the FFR value (FFR Pre-PCI 0.69 ± 0.02 vs. FFRRAP Pre-PCI 0.63 ± 0.03, p<0.0001). 21 patients had an FFR ≤ 0.8 in the group. If right atrial pressure were utilized to calculate FFR prior to PCI, an additional 9 patients would have been re-categorised to an FFR ≤ 0.8. Following PCI, mean FFR was lower when RAP was incorporated (Post PCI FFRRAP 0.93±0.05 vs. Post PCI FFR 0.95 ± 0.06, p<0.001).
  
  
  CONCLUSIONS
  Incorporation of right atrial pressure into the calculation of FFR significantly alters FFR values and may potentially reclassify lesions below ischaemic thresholds.
authors.affiliation: Department of Cardiology St Vincent's Hospital, Fitzroy, Victoria, Australia. jamielayland@hotmail.com
authors.forename: Jamie
authors.initials: J
authors.lastname: Layland
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Wilson
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Whitbourn
authors.forename: Andrew T
authors.initials: AT
authors.lastname: Burns
authors.forename: Jithendra
authors.initials: J
authors.lastname: Somaratne
authors.forename: George
authors.initials: G
authors.lastname: Leitl
authors.forename: Andrew I
authors.initials: AI
authors.lastname: Macisaac
mesh_terms: D000368:Aged; D016280:Atrial Function, Right / Q000502:physiology*; D062185:Atrial Pressure / Q000502:physiology*; D015331:Cohort Studies; D003324:Coronary Artery Disease / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery; D017558:Elective Surgical Procedures / Q000379:methods*; D005260:Female; D053805:Fractional Flow Reserve, Myocardial / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D062645:Percutaneous Coronary Intervention / Q000379:methods*; D011446:Prospective Studies