Acute and one year follow-up results after vessel size adapted PTCA using intracoronary ultrasound

Recent randomized clinical trials have reported a reduction in restenosis with intracoronary stents and have 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 PTCA results may be optimized by determining vessel dimensions before intervention, using intravascular ultrasound. This may lead to long-term PTCA results equivalent to PTCA and the additional placement of a stent. The purpose of this prospective non-randomized single-centre 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 artery obstructions.

From January 1995 to December 1995 the morphological dimensions of target lesions were determined in 144 patients with 152 lesions by intravascular ultrasound prior to conventional balloon angioplasty. Quantitative assessment of the vascular dimensions were assessed on-line and the diameter of the balloon catheter was adapted to the external elastic membrane diameter at the lesion site. Using this strategy, mean balloon diameter was 4.0 +/- 0.5 mm and mean pressure for complete balloon expansion was 7 +/- 2 atmospheres. Acute and one year follow-up results were obtained in all 144 patients. Acute events occurred in two patients (one death and one acute surgical revascularization). During one year follow-up, 16 patients (12%) had a clinical event including one cardiac death, two transmural myocardial infarctions, 10 repeat PTCAs within the target lesion and three elective coronary artery bypass grafts (CABG). In 75% (n:112) control angiography was performed and revealed an angiographic restenosis rate of 21% using the NHLBI criteria of a diameter stenosis > 50%.

Intravascular ultrasound provides an accurate and precise description of vascular dimensions at the site of the stenotic lesion. The use of balloon diameters following these measurements appears to be (1) safe in the acute setting with a low number of in hospital events and (2) gives a low restenosis rate and number of clinical events at one year follow-up. These promising results warrant verification in larger-scale randomized trials.