Improved assessment of functional severity of coronary artery stenosis by analysis of combined intracoronary pressure and flow velocity signals

Aims First, to establish the diagnostic performance of the pressure gradient at a standardized mean velocity (dPv) as derived from the cycle-averaged stenosis pressure gradientvelocity (ΔP-v) relationship obtained by administration of adenosine and second, to determine whether dPv can be assessed from contrast medium-induced submaximal hyperemia. Methods and results Distal coronary pressure and velocity were simultaneously recorded in 64 patients during the response to an intracoronary injection of adenosine. dPv was assessed at velocities between 20 and 50 cm/s. The pressure gradient at a mean flow velocity of 30 cm/s (dPv30) yielded an excellent diagnostic performance against FFR≤0.8 (area under the curve 0.96; sensitivity 84%; specificity 96%; accuracy 89%). In a subgroup of 21 patients, measurements were repeated throughout contrast medium-induced reactive hyperemia. Peak velocity and pressure gradient were lower compared to adenosine, but the course of the corresponding ΔP-v relationships coincided very well over the common velocity range, with no difference in dPv30. Conclusions dPv30 reliably detects functionally significant coronary lesions. It derives from stenosis hemodynamics and can be obtained with submaximal hyperemia, such as following injection of contrast medium, thereby obviating the maximal vasodilation by adenosine required for FFR or other established hyperemic parameters of functional stenosis severity.