Acute results, complications, and effect of lesion characteristics on outcome with the solid-state, pulsed-wave, mid-infrared laser angioplasty system: final multicenter registry report. Holmium:YAG Laser Multicenter Investigators

BACKGROUND AND OBJECTIVE

The solid-state, mid-infrared holmium:YAG laser (2.1 microm wavelength) is a relatively new percutaneous device that has recently been evaluated in a multicenter study. Because of its unique wavelength and photoacoustic effects on atherosclerotic plaques, this laser may be useful in treatment of symptomatic patients with coronary artery disease. This study sought to evaluate the safety and efficacy of mid-infrared laser angioplasty in the treatment of coronary artery lesions.

PATIENTS AND METHODS

Laser angioplasty was performed on 2,038 atherosclerotic lesions in 1,862 consecutive patients with a mean age of 61 +/- 11 years. Clinical indications included unstable angina (69%), stable angina (20%), acute infarction (6%), and positive exercise test (5%). Complex lesion morphology included eccentricity (62%), thrombus (30%), total occlusion (27%), long lesions (14%), and saphenous vein grafts (11%).

RESULTS

This laser catheter alone successfully reduced stenosis (>20%) in 87% of lesions. With adjunct balloon angioplasty, 93% procedural success was achieved. The presence of thrombus 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 tortuosity 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 procedural success (OR = 0.57 [95% confidence interval 0.34, 0.97], P = .03), and calcified lesions required significantly more energy pulses than noncalcified lesions (119 +/- 91 pulses vs. 101 +/- 86 pulses, respectively, P = .0002). Complications included in-hospital bypass surgery 2.5%, Q-wave myocardial infarction 1.2%, and death 0.8%. Perforation occurred in 2.2% of patients; major dissection in 5.8% of patients, and spasm in 12% of patients. No predictor of major complications was identified. Six-month angiographic restenosis was documented in 54% of patients, and clinical restenosis occurred in 34% of patients.

CONCLUSION

Mid-infrared laser has a safety profile similar to that of other debulking devices. This laser may be useful in select patients presenting with acute ischemic syndromes associated with intracoronary thrombus; however, like other coronary lasers, it is limited by the need for adjunctive balloon angioplasty and/or stenting to achieve adequate final luminal diameter. No beneficial effects on reducing 6-month restenosis rates were observed.

Clinical experience with the use of the angled-balloon dilatation catheter

A special balloon catheter has been developed for use in coronary angioplasty. The balloon portion has a 135 degrees - 145 degrees angle at its mid portion. It is designed for stenosis located at an angle of the coronary artery. We investigated the use of this catheter in 39 patients who underwent percutaneous transluminal coronary angioplasty (PTCA): 29 men and 10 women. PTCA was attempted in 43 stenotic sites. Thirty-two stenoses were located at the angled portion of the dilated arteries. Eleven stenoses were located at the side branches of the acutely angled bifurcations. Twenty stenoses were in the right coronary artery distribution. Twenty-two stenoses were in the left coronary artery distribution. One stenosis was at the origin of the left internal mammary artery. Forty-one stenoses were angioplastied successfully (95.4%). No angiographic evidence of intimal tear or dissection was noted in all of the dilated vessels. Acute closure was not observed. The mean follow-up period was 239.5 days. Six patients (15.4%) were found to have restenosis. We conclude that the use of the angled-balloon dilatation catheter provides the potential benefit of reducing intimal trauma and dissection during PTCA of certain coronary anatomies--stenosis at the angled portion or at the takeoff of the side branch of a bifurcation.