ENDOCORONARY ULTRASONOGRAPHY AND QUANTITA TIVE CORONARY ANGIOGRAPHY -CORRELATIONS BEFORE AND AFTER CORONARY ANGIOPLASTY

A comparative study of the results of quantitative coronary angiograph y and endocoronary ultrasonography was performed in 37 patients underg oing percutaneous transluminal coronary angioplasty to determine the c orrelations between the two methods The analyses were made before and after angioplasty at the site of stenosis and on a reference segment. A complete study before and after angioplasty using both techniques wa s only possible in 24 cases. The quantitative ultrasonographic analysi s consisted of measurement of two orthogonal diameters, total surface area of the vessel, the endoluminal surface area and surface area of p laque. Transluminal coronary angioplasty acts mainly by forcing the pl aque outwards. Ultrasonography showed a decrease in plaque area, from 10.5 +/- 6 mm(2) to 9.8 +/- 5.5 mm(2) and the total surface area of th e vessel increased from 12.8 +/- 0.7 to 15.3 +/- 6.9 mm(2) (p < 0.05). This accounted for the gain in main surface area of the stenosed lume n, from 2.28 +/- 1.28 to 5.9 +/- 2.65 mm(2) (p < 0.001). The correlati ons between quantitative coronary angiography and ultrasonography at t he site of stenosis were only significant after angioplasty both the v essel diameter (r = 0.67; p < 0.0002) and endoluminal surface area (r = 0.63; p < 0.0001). A correlation was not observed before angioplasty because of the complexity of the plaque and its excentric location. A t the reference site, the correlations between ultrasonography and ang iography before and after angioplasty were significant but not very cl ose (Spearman coefficient 0.53 and 0.82 respectively, p < 0.001). Ther efore, correlations between quantitative data obtained by coronary ang iography and ultrasonography are modest in patients undergoing translu minal coronary angioplasty. The ultrasonographic information is more q ualitative, enabling a better understanding of the mechanism of the th erapeutic procedure and allowing optimal choice of the appropriate too l.