title: Left ventricular end-diastolic pressure affects measurement of fractional flow reserve.
abstract: BACKGROUND
  Fractional flow reserve (FFR), the hyperemic ratio of distal (Pd) to proximal (Pa) coronary pressure, is used to identify the need for coronary revascularization. Changes in left ventricular end-diastolic pressure (LVEDP) might affect measurements of FFR.
  
  
  METHODS
  LVEDP was recorded simultaneously with Pd and Pa during conventional FFR measurement as well as during additional infusion of nitroprusside. The relationship between LVEDP, Pa, and FFR was assessed using linear mixed models.
  
  
  RESULTS
  Prospectively collected data for 528 cardiac cycles from 20 coronary arteries in 17 patients were analyzed. Baseline median Pa, Pd, FFR, and LVEDP were 73 mmHg, 49 mmHg, 0.69, and 18 mmHg, respectively. FFR<0.80 was present in 14 arteries (70%). With nitroprusside median Pa, Pd, FFR, and LVEDP were 61 mmHg, 42 mmHg, 0.68, and 12 mmHg, respectively. In a multivariable model for the entire population LVEDP was positively associated with FFR such that FFR increased by 0.008 for every 1-mmHg increase in LVEDP (beta=0.008; P<0.001), an association that was greater in obstructed arteries with FFR<0.80 (beta=0.01; P<0.001). Pa did not directly affect FFR in the multivariable model, but an interaction between LVEDP and Pa determined that LVEDP's effect on FFR is greater at lower Pa.
  
  
  CONCLUSIONS
  LVEDP was positively associated with FFR. The association was greater in obstructive disease (FFR<0.80) and at lower Pa. These findings have implications for the use of FFR to guide revascularization in patients with heart failure.
  The impact of left ventricular diastolic pressure on measurement of fractional flow reserve (FFR) is not well described. We present a hemodynamic study of the issue, concluding that increasing left ventricular diastolic pressure can increase measurements of FFR, particularly in patients with FFR<0.80 and lower blood pressure.
authors.affiliation: Medical University of South Carolina, Charleston, SC, USA.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Leonardi
authors.forename: Jacob C
authors.initials: JC
authors.lastname: Townsend
authors.forename: Chetan A
authors.initials: CA
authors.lastname: Patel
authors.forename: Bethany J
authors.initials: BJ
authors.lastname: Wolf
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Todoran
authors.forename: Valerian L
authors.initials: VL
authors.lastname: Fernandes
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Nielsen
authors.forename: Daniel H
authors.initials: DH
authors.lastname: Steinberg
authors.forename: Eric R
authors.initials: ER
authors.lastname: Powers
mesh_terms: D000241:Adenosine / Q000494:pharmacology; D000368:Aged; D000369:Aged, 80 and over; D001783:Blood Flow Velocity / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology*; D017023:Coronary Angiography / Q000379:methods; D003326:Coronary Circulation / Q000502:physiology*; D003331:Coronary Vessels / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged
chemical_list: D000241:Adenosine
keywords: coronary artery disease; fractional flow reserve; heart failure; revascularization