Resting Pd/Pa measured with intracoronary pressure wire strongly predicts fractional flow reserve.
OBJECTIVE
To investigate the relationship between resting distal coronary pressure to aortic pressure ratio (Pd/Pa) and fractional flow reserve (FFR) obtained during maximal hyperemia.


BACKGROUND
FFR is an invasive index of the functional severity of a coronary artery stenosis determined from coronary pressure measurements. It is generally believed that there is little correlation between resting Pd/Pa and FFR obtained during maximal hyperemia. We have therefore studied this relationship in a large cohort of patients who had undergone pressure- wire assessments.


METHODS
528 consecutive pressure-wire studies performed in 483 patients over a 2-year period were retrospectively analyzed.


RESULTS
A linear correlation between resting Pd/Pa and FFR post-pharmacological hyperemia was observed (rho = 0.74; p < 0.0001). When a FFR of < or = 0.75 (or < or = 0.80 as per FAME) was defined as positive, a resting Pd/Pa of < or = 0.85 (< or = 0.87) had a positive predictive value (PPV) of 95% (94.6%), while a resting Pd/Pa of > or = 0.93 (> or = 0.96) had a negative predictive value (NPV) of 95.7% (93%).


CONCLUSIONS
We demonstrate a strong correlation between resting Pd/Pa and FFR. Resting values of Pd/Pa can be used to predict a positive FFR result with relatively high PPV and NPV. This may potentially obviate the need for adenosine infusion in a proportion of pressure-wire studies.
Manchester Heart Centre, Manchester Royal Infirmary, Biomedical Research Centre, Manchester, United Kingdom.
Mamas A
MA
Mamas
Simon
S
Horner
Elise
E
Welch
Anthony
A
Ashworth
Simon
S
Millington
Doug
D
Fraser
Farzin
F
Fath-Ordoubadi
Ludwig
L
Neyses
Magdi
M
El-Omar
D054058:Acute Coronary Syndrome / Q000175:diagnosis / Q000503:physiopathology; D000241:Adenosine; D001011:Aorta / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology*; D006328:Cardiac Catheterization / Q000295:instrumentation / Q000379:methods*; D015331:Cohort Studies; D003326:Coronary Circulation / Q000502:physiology*; D023921:Coronary Stenosis / Q000175:diagnosis* / Q000503:physiopathology*; D003331:Coronary Vessels / Q000502:physiology; D005260:Female; D006801:Humans; D006940:Hyperemia / Q000175:diagnosis / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012372:ROC Curve; D012189:Retrospective Studies; D012720:Severity of Illness Index; D014665:Vasodilator Agents
D014665:Vasodilator Agents; D000241:Adenosine