[Advantages in using intravascular ultrasound in percutaneous transluminal coronary angiography]

Recent randomized clinical trials reported a reduction of restenosis using intracoronary stents and suggested that this restenosis reduction is a result of the higher immediate luminal gain in comparison to conventional percutaneous transluminal coronary angioplasty (PTCA). The hypothesis of this study is based on the assumption that IVUS guided PTCA leads to equivalent long term PTCA results as compared to PTCA and the additional placement of a stent. Thus, the purpose of this non-randomized single center study was to evaluate (1) the safety and efficacy and (2) the long term outcome of vessel size adapted PTCA in patients with native coronary lesions. From April 1995 to March 1996 the morphological dimensions of the target lesions were determined in 107 patients with 108 lesions by intravascular ultrasound prior to conventional balloon angioplasty. Quantitative parameters of the vascular dimensions were assessed on-line and the diameter of the balloon catheter was adapted to the external elastic membrane (EEM) at the lesion site minus 10%. Using this strategy, mean balloon diameter was 4.1 +/- 0.5 mm. Acute and one year clinical follow-up results were obtained in all 107 patients. Angiographic success was defined as a final percent diameter stenosis of < 30%. The following criteria determined by postinterventional IVUS were also used to define a successful PTCA: luminal CSA gain of > 30% with an angiographically patent flow (TIMI 3). Acute events occurred in two patients (one death and one successful acute surgical revascularisation). During one year follow-up, 11 patients had a clinical event including death, Q-wave MI, surgical revascularisation, and repeat PTCA. In 83 patients (78%), control angiography was performed and revealed an angiographic restenosis rate of 21% using the NHLBI criterion of a diameter stenosis > 50%

The use of balloon diameters following these measurements is safe in the acute setting with a low number of in hospital events and effective in reducing clinical events as well as angiographic restenosis rates during one year follow-up. These promising results warrant verification in larger scale randomized trials.