INTRACORONARY ULTRASOUND BEFORE CORONARY INTERVENTIONS - A PROSPECTIVE COMPARISON OF 2 DIFFERENT CATHETERS

Intravascular ultrasound (IVUS) provides unique information about the coronary arterial wall that can be used to guide transcatheter therapy . In this prospective study, two different IVUS systems were compared with respect to feasibility of imaging before intervention and angiogr aphic changes induced by the simple advancement of the catheter across the lesion. Eighty-five patients (mean age 59 +/- 10 yr, 11 female) w ere studied with IVUS before intervention. In 34 patients, a 4.8F (1.6 -mm) IVUS catheter was used (Group I), whereas in the remaining 51 pat ients a 3.5F (1.2-mm) IVUS catheter was used (Group II). Quantitative angiography was performed before and after the IVUS study to determine potential changes in lumen diameter. Clinical and angiographic charac teristics were similar in the two groups. A successful IVUS interrogat ion of the target lesion was obtained more frequently in Group II (45/ 51 (88%) vs. 19/34 (56%) patients, P < 0.01). After the IVUS study, a change in minimal lumen diameter was seen in Group I (baseline 0.84 +/ - 0.2 vs. final 1.17 +/- 0.2 mm, P < 0.001) and Group II patients (bas eline 0.80 +/- 0.3 vs. final 1.03 +/- 0.4 mm, P < 0.01). In the 64 les ions successfully crossed, the absolute gain in lumen diameter was sig nificantly higher in Group I (0.40 +/- 0.2 vs. 0.23 +/- 0.2 mm, P < 0. 05). In addition, an inverse correlation was found between baseline mi nimal lumen diameter and the absolute lumen gain induced by the IVUS s tudy in Group I (r = -0.47, P < 0.05) but not in Group II patients (r = -0.16, NS). Neither angiographic nor echogenic lesion characteristic s were associated with the change in lumen diameter. When multivariate analysis was applied, catheter size was the only independent predicto r of lumen gain induced by IVUS after adjustment. Thus, the advancemen t of IVUS catheters across severe coronary lesions induces significant angiographic changes consistent with plaque remodeling and a Dotter e ffect. The use of smaller catheters not only allows a higher number of lesions to be studied before intervention, but also lessens the mecha nical disruption of the plaque, yielding a more accurate and veracious picture of baseline plaque characteristics. (C) 1997 Wiley-Liss, Inc.