Solid-state, pulsed-wave, mid-infrared coronary laser angioplasty in de novo versus restenosis lesions: Observations from a multicenter study

The following is a study of the response of de novo versus restenosis coronary lesions to pulsed-wave, mid-infrared (holmium:YAG) laser assisted angioplasty. De novo lesions contain thrombi, cholesterol, and fibrosis, whereas restenotic lesions are composed of smooth muscle cells corresponding to injury caused by preceding balloon inflations. It is not known whether the different composition affects results of treatment by laser. In a clinical multicenter study, a mid-infrared, solid-state, pulsed-wave laser (holmium:YAG, 2.1 μm wavelength, 250-600 mJ/pulse, 5 Hz) was applied for revascularization of de novo and restenosis coronary lesions. Analysis of data was undertaken to document laser success, complications, and restenosis rate and to define whether the type of lesion treated had an effect on laser success and related complications. A total of 1340 patients with 1465 stenoses presented with symptomatic coronary artery disease. Laser success was 87 and 86% in these lesions, respectively. Overall procedural success of 93% was achieved. Restenosis lesions, known to be composed of smooth muscle proliferation, needed more laser energy for ablation than de novo lesions, which contain an atherosclerotic plaque (130 ± 123 pulses vs 109 ± 31, p = 0.001). Procedure-related Q-wave myocardial infarction was significantly higher in patients with de novo lesions over patients with restenosis lesions (1.4 vs 0.2%, p = 0.05). With the mid-infrared, pulsed-wave, holmium:YAG laser, the composition of the target lesion affects the energy level required, as well as the procedure-related complications.