Quantitative angiographic comparison of elastic recoil after coronary excimer laser-assisted balloon angioplasty and balloon angioplasty alone

Objectives. Coronary lumen changes during and after excimer laser-assisted balloon angioplasty were measured by quantitative coronary angiography, and the results were compared with the effects of balloon angioplasty alone. Background. Reduction of atherosclerotic tissue mass by laser ablation in the treatment of coronary artery disease may be more effective in enlarging the lumen than balloon angioplasty alone. Methods. A series of 57 consecutive coronary lesions successfully treated by xenon chloride excimer laser-assisted balloon angioplasty were individually matched with 57 coronary artery lesions successfully treated by balloon angioplasty alone. The following variables were measured by quantitative coronary analysis: 1) ablation by laser, 2) stretch by balloon dilation, 3) elastic recoil, and 4) acute gain. Results. Matching by stenosis location, reference diameter and minimal lumen diameter resulted in two comparable groups of 57 lesions with identical baseline stenosis characteristics. Minimal lumen diameter before excimer laser-assisted balloon angioplasty and balloon angioplasty alone were (mean ± SD) 0.73 ± 0.44 and 0.74 ± 0.43 mm, respectively. Laser ablation significantly improved minimal lumen diameter by 0.56 ± 0.44 mm before adjunctive balloon dilation. In both treatment groups, similar-sized balloon catheters (2.59 ± 0.35 and 2.56 ± 0.40 mm, respectively) were used. After laser-assisted balloon angioplasty, elastic recoil was 0.84 ± 0.30 mm (32% of balloon size), which was identical to that after balloon angioplasty alone, namely, 0.82 ± 0.32 mm (32%). Consequently, both interventions resulted in similar acute gains of 1.02 ± 0.52 and 1.00 ± 0.56 mm, respectively. Minimal lumen diameter after intervention was equal in both groups: 1.75 ± 0.35 and 1.75 ± 0.34 mm, respectively. The statistical power of this study in which a 25% difference in elastic recoil (0.2 mm) between groups was considered clinically important was 95%. Conclusions. In matched groups of successfully treated coronary lesions, xenon chloride excimer laser ablation did not reduce immediate elastic recoil after adjunctive balloon dilation or improve the final angiographic outcome compared with balloon angioplasty alone using similar-sized balloon catheters.