ASSESSMENT OF CORONARY-ARTERY STENOSIS PRESSURE-GRADIENT BY QUANTITATIVE CORONARY ARTERIOGRAPHY IN PATIENTS WITH CORONARY-ARTERY DISEASE

The aim of the study described here was to correlate coronary artery ( CA) stenosis pressure gradients calculated by quantitative coronary ar teriography (QCA) to invasively measured transstenotic pressure drops in patients with anginal symptoms and with known or suspected coronary artery disease. Furthermore, the known mathematical models are improv ed by introducing (1) pressure catheter-corrected minimal stenosis are a, (2) modification of flow assumptions, and (3) stenosis exit angle. Included in the study were 45 patients with 61 stenoses. The visually estimated CA lesion severity in these non-complex stenoses was in the equivocal range of 40-70%. All measurements were performed after intra coronary administration of nifedipine and nitroglycerine. Stenosis dim ensions were assessed from magnified cinefilms, using handheld caliper s. Highly significant overall correlation was found between measured a nd calculated pressure gradients with correction for the impact of the intracoronary catheter (P<0.00001, r=0.84). In particular, a substant ial number of stenoses with haemodynamically-insignificant pressure gr adients were identified by hydrodynamic calculations. In conclusion, t he great majority of the coronary artery stenoses could be classified reliably by QCA as being haemodynamically insignificant or significant , respectively.