Basal stenosis resistance index derived from simultaneous pressure and flow velocity measurements.
OBJECTIVE
Vasodilator-free basal stenosis resistance (BSR) equals fractional flow reserve (FFR) accuracy for ischaemia-inducing stenoses. Nonetheless, basal haemodynamic variability may impair BSR accuracy compared with hyperaemic stenosis resistance (HSR). We evaluated the influence of basal haemodynamic variability, as encountered in practice, on BSR accuracy versus HSR when derived from simultaneous pressure and flow velocity measurements, and determined its diagnostic performance for HSR-defined significant stenoses.


RESULTS
Simultaneous coronary pressure and flow velocity were obtained in 131 stenoses. The impact of basal haemodynamic conditions on BSR was evaluated by means of their relationship with the relative difference between BSR and HSR. Diagnostic performance of BSR, FFR, iFR, and resting Pd/Pa was assessed by comparing the area under the curve (AUC), using HSR as reference standard. The relative difference between BSR and HSR was not associated with basal heart rate, aortic pressure or rate pressure product. Among all stenoses, as well as within the 0.6-0.9 FFR range, BSR AUC was significantly greater than resting Pd/Pa and iFR AUC; all other AUCs were equivalent.


CONCLUSIONS
With simultaneous pressure and flow velocity measurements, basal conditions do not systematically limit BSR accuracy compared with HSR. Consequently, diagnostic performance of BSR is equivalent to FFR, and closely approximates HSR.
AMC Heart Center, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
Tim P
TP
van de Hoef
Ricardo
R
Petraco
Martijn A
MA
van Lavieren
Sukhjinder
S
Nijjer
Froukje
F
Nolte
Sayan
S
Sen
Mauro
M
Echavarria-Pinto
José P S
JP
Henriques
Karel T
KT
Koch
Jan
J
Baan
Robbert J
RJ
de Winter
Maria
M
Siebes
Jos A E
JA
Spaan
Jan G P
JG
Tijssen
Martijn
M
Meuwissen
Javier
J
Escaned
Justin E
JE
Davies
Jan J
JJ
Piek
D000368:Aged; D006328:Cardiac Catheterization / Q000379:methods; D003251:Constriction, Pathologic / Q000175:diagnosis* / Q000628:therapy*; D023921:Coronary Stenosis / Q000628:therapy*; D005260:Female; D053805:Fractional Flow Reserve, Myocardial / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D014665:Vasodilator Agents / Q000627:therapeutic use
D014665:Vasodilator Agents