Reviparin use during and after coronary angioplasty did not reduce the occurrence of major clinical events or the incidence of angiographic restenosis over 30 weeks.

To determine the temporal evolution of laser induced tissue ablation, arterial wall specimens with either hard calcified or fatty plaques and normal tissue were irradiated in a 0.9% saline solution using a XeCl excimer laser (wavelength 308 nm, energy fluence 7 J/cm2, pulse width 30 ns) through a 600 microns fused silica fiber pointing perpendicular either at a 0.5 mm distance or in direct contact to the vascular surface. Radiation of a pulsed dye laser (wavelength 580 nm) was used to illuminate the tissue surface. The ablation process and the arising bubble above the tissue surface were recorded with a CCD camera attached to a computer based image-processing system. Spherical cavitation bubbles and small tissue particles emerging from the irradiated area have been recorded. The volume of this bubble increased faster for calcified plaques than for normal tissue.

In order to develop a predictive model for the risk of early lesion deterioration following successful coronary balloon angioplasty (PTCA) based on clinical, pre-angioplasty and procedural characteristics, 154 lesions in 146 consecutive patients undergoing successful PTCA for stable/unstable angina were examined by quantitative coronary analysis immediately after and within 24 h of angioplasty. An angiographic complication score was used prospectively, classifying the lesion morphology post-PTCA into class 0: no complication and classes 1 to 3, according to purely descriptive morphological characteristics. Significant deterioration, defined as a decrease in minimal luminal diameter of more than 2 standard deviations of duplicate measurements post-intervention (0.54 mm; 95% confidence limit for variability using quantitative angiography) was found in 28 lesions (18%), and a total reocclusion in seven lesions (5%). The angiographic complication score (P = 0.019), prior to myocardial infarction (P = 0.076), minimal luminal diameter immediately post-intervention (P = 0.021) and gain of PTCA (P = 0.042) were found to be independently predictive of early lesion deterioration by multiple logistic regression analysis. Identification of these factors and their associated risk should improve success, and understanding of the early vascular response following coronary angioplasty. Moreover, these results have implications for clinical restenosis studies, particularly those assessing the effect of pharmacological interventions on late restenosis rates.

Formation of aneurysms in coronary arteries can be observed following percutaneous transluminal balloon angioplasty but has not been reported previously after coronary excimer laser angioplasty in humans. Stand alone coronary excimer laser angioplasty was performed in a 49-year-old man with a 75% left anterior descending artery stenotic lesion and exertional angina, documenting a good angiographic result postintervention. Control angiography 6 months after the procedure revealed an aneurysm distal to a 90% restenosis in the area of ablation.

Of 523 consecutive patients undergoing elective percutaneous transluminal coronary angioplasty (PTCA) and 83 patients treated with coronary excimer laser angioplasty (ELCA), 17 (3.3%) had in-laboratory occlusion following PTCA and 25 (30%) following ELCA; they were enrolled into a prospective study. Successful management (reopened vessel, patency at repeat angiography within 24 h, no death, no myocardial infarction (MI), no emergency bypass surgery) including repeat lasing, subsequent PTCA, use of intracoronary nitroglycerin or streptokinase was achieved in 24 (96%) of the 25 patients with acute occlusion during ELCA. An anterior MI occurred in one patient of the laser group. Repeat balloon dilatation was successfully performed in seven of the 17 patients (41%) with acute closure during PTCA. Among the 10 patients with persistent occlusion after PTCA, five developed a limited myocardial infarction (35%). One patient required emergency CABG, and died peri-operatively. Severe spasm prior to occlusion defined by a new coronary flow depression without evidence of dissection or thrombus showed a significant positive association with acute occlusion during ELCA (P = 0.0008). Thus, in contrast to occlusion during PTCA, subsequent balloon dilatation was successfully performed in the majority of patients with acute occlusion during ELCA, implying that different underlying mechanisms are responsible for this complication. In this limited patient group, occlusion after excimer laser angioplasty was much more frequent than closure during PTCA, but was infrequently associated with major events such as myocardial infarction or death.