Assessment of the results of percutaneous transluminal coronary angioplasty using an integrated ultrasound imaging-angioplasty catheter.

To evaluate the results percutaneous transluminal coronary angioplasty (PTCA), intravascular ultrasound imaging was performed in 32 proximal coronary arterial segments and in 16 atherosclerotic lesions after PTCA in 13 patients using a 5 Fr balloon catheter with an ultrasound transducer mounted just proximal to the balloon. Simultaneous angiographic measurements of vessel diameter were also performed using electronic calipers from contrast cine angiograms. There was good correlation between ultrasound and angiographic minimum luminal diameters of the normal proximal vessel (y = 0.59x + 1.49, r = 0.70, P<0.01, n = 32). However, the luminal diameter measured by intravascular ultrasound was significantly greater than when measured by contrast angiography (2.81 +/- 0.10 vs. 2.34 +/- 0.12 mm, n = 16, P<0.001, mean +/- SEM). Post-PTCA, there was good correlation between ultrasound and angiographic minimum luminal diameters of the lesion (y = 0.62x +/- 1.42, r = 0.76, P<0.001, n = 16), but again luminal diameters were significantly greater when measured by intravascular ultrasound compared to contrast angiography (2.61 +/- 0.08 vs. 1.89 +/- 0.10 mm, n = 16, P<0.001). Furthermore, residual stenosis was significantly less when determined by intravascular ultrasound than by contrast angiography(7.3 +/- 2.0 vs. 18. +/- 2.1%, n = 16, P<0.001). Intravascular ultrasound was able to detect coronary calcification that was not evident by contrast coronary angiography in 8 of 16 lesions. Post-PTCA, dissection was evident in four lesions by ultrasound, whereas dissection was appreciated in only three lesions by contrast angiography. We conclude that intravascular ultrasound can accurately measure the luminal diameter of coronary arteries both before and after PTCA and reveals more information about the lesion characteristics than does conventional contrast angiography. (C) 1994 Wiley-Liss, Inc.