ACUTE RESULTS, COMPLICATIONS, AND EFFECT OF LESION CHARACTERISTICS ONOUTCOME WITH THE SOLID-STATE, PULSED-WAVE, MIDINFRARED LASER ANGIOPLASTY SYSTEM - FINAL MULTICENTER REGISTRY REPORT

Background and Objective: The solid-state, mid-infrared holmium:YAG la ser (2.1 mu m wavelength) is a relatively new percutaneous device that has recently been evaluated in a multicenter study. Because of its un ique wavelength and photoacoustic effects on atherosclerotic plaques, this laser may be useful in treatment of symptomatic patients with cor onary artery disease. This study sought to evaluate the safety and eff icacy of mid-infrared laser angioplasty in the treatment of coronary a rtery lesions. Patients and Methods: Laser angioplasty was performed o n 2,038 atherosclerotic lesions in 1,862 consecutive patients with a m ean age of 61 +/- 11 years. Clinical indications included unstable ang ina (69%), stable angina (20%), acute infarction (6%), and positive ex ercise test (5%). Complex lesion morphology included eccentricity (62% ), thrombus (30%), total occlusion (27%), long lesions (14%), and saph enous vein grafts (11%). Results: This laser catheter alone successful ly reduced stenosis (>20%) in 87% of lesions. With adjunct balloon ang ioplasty, 93% procedural success was achieved. The presence of thrombu s within the target lesion was a predictor of procedural success (OR = 2.0 [95% confidence interval 2.0, 4.0], P=.04). Bifurcation lesions ( OR = 0.5 [95% confidence interval 0.2, 1.0], P=.05) and severe tortuos ity of the treated vessel (OR = 0.4 [95% confidence interval 0.2, 0.9] , P=.02) were identified as significant predictors of decreased laser success. Calcium within the lesion was associated with reduced procedu ral success (OR = 0.57 [95% confidence interval 0.34, 0.97], P=.03), a nd calcified lesions required significantly more energy pulses than no ncalcified lesions (119 +/- 91 pulses vs. 101 +/- 86 pulses, respectiv ely, P=.0002). Complications included in-hospital bypass surgery 2.5%, Q-wave myocardial infarction 1.2%, and death 0.8%. Perforation occurr ed in 2.2% of patients; major dissection in 5.8% of patients, and spas m in 12% of patients. No predictor of major complications was identifi ed. Six-month angiographic restenosis was documented in 54% of patient s, and clinical restenosis occurred in 34% of patients. Conclusion: Mi d-infrared laser has a safety profile similar to that of other debulki ng devices. This laser may be useful in select patients presenting wit h acute ischemic syndromes associated with intracoronary thrombus; how ever, like other coronary lasers, it is limited by the need for adjunc tive balloon angioplasty and/or stenting to achieve adequate final lum inal diameter. No beneficial effects on reducing 6-month restenosis ra tes were observed. (C) 1998 Wiley-Liss, Inc.