HIGH-FIDELITY TRANSLESIONAL PRESSURE-GRADIENTS DURING PERCUTANEOUS TRANSLUMINAL CORONARY ANGIOPLASTY - CORRELATION WITH QUANTITATIVE CORONARY ANGIOGRAPHY

A fiberoptic pressure sensor mounted on an 0.018-inch guidewire (Press ure Guide) was used to measure the transstenotic pressure gradient in 30 patients undergoing percutaneous transluminal coronary angioplasty (PTCA) with lesions considered suitable for quantitative coronary angi ographic (QCA) assessment. The aim of the study was to correlate press ure gradients with parameters obtained with QCA. After intracoronary i njection of 125 mug of nitroglycerin, multiple angiographic views were taken of the lesion. The Pressure Guide fiberoptic sensor was then po sitioned distal to the stenosis and the pressure gradients were record ed before and after PTCA. There was a significant correlation between mean pressure gradients (DELTAP) and percent diameter stenosis (r = 0. 73; p < 0.001) and absolute stenosis diameter (r = - 0.67; p < 0.001) and with percent area stenosis (r = 0.69; p < 0.001) and absolute sten osis area (r = -0.63; p < 0.001). The closest relationship, though, wa s found with stenotic flow reserve (SFR), which is an integrated param eter calculated from QCA. This relationship can be described by the eq uation: DELTAP = 65.2 - 12.6 SFR (r = -0.79; p < 0.001). With a measur ed gradient of >15 mm Hg, the sensitivity was 94% and the specificity 96% to predict an SFR <3.5. In conclusion, a statistically significant relationship could be found between stenosis pressure gradients and a ngiographic parameters in this study with lesions without complicated morphology. The independent information obtained by pressure gradient measurement may be of particular value in intermediately severe lesion s or in stenoses where the angiographic assessment otherwise is diffic ult.