Prestenotic and Poststenotic Flow Measurement to Assess Severity of Coronary Artery Stenosis

Abstract

The purpose of this study was to investigate differences between prestenotic and poststenotic intracoronary Doppler flow velocities and to determine whether these hemodynamic parameters of coronary flow demonstrate a correlation with geometrically measured coronary artery stenosis. A low-profile (0.018-in.) Doppler angioplasty guidewire capable of providing spectral flow velocity data was used to measure blood flow velocities both proximal and distal of 95 coronary artery stenoses ranging from 15% to 82% in diameter. Percent diameter stenoses were analyzed by quantitative coronary arteriography. In comparison with prestenotic measurements poststenotic Doppler flow velocities were markedly reduced in coronary artery stenoses with a diameter reduction greater than 50% in quantitative angiography. In stenoses less than 50% no difference between prestenotic and poststenotic parameters of coronary flow could be found. Prestenotic Doppler data demonstrated no correlation to percent diameter stenosis, whereas poststenotic flow data correlated moderately with percent diameter stenosis. Poststenotic Doppler data of stenoses below 50% differed significantly from stenoses above 50%. In conclusion, intracoronary Doppler flow velocity measurements performed distal to coronary artery stenoses contribute to the evaluation of hemodynamic significances of particular coronary artery stenoses.