Application of excimer laser an angioplasty in acute myocardial infarction

Background and Objective: Patients presenting with acute myocardial infarct ion who fail to respond to standard therapy with thrombolytics or have cont raindications for their use oftentimes need revascularization with a mechan ical device for removal of an occlusive coronary thrombus and its underlyin g atherosclerotic plaque. As both thrombi and plaques absorb laser energy i n the ultraviolet wavelength (308 nm), we studied the feasibility and safet y of excimer laser angioplasty in selective patients with complicated acute myocardial infarction. Study Design/Materials and Methods: Fifty patients with acute myocardial in farction complicated by continuous chest pain and/or ischemia who had a tot al of 54 obstructive lesions were treated with percutaneous excimer coronar y laser angioplasty (ELCA). A Q-wave myocardial infarction was documented i n 56% and a non-Q-wave myocardial infarction in 44%. The baseline left vent ricular ejection fraction was reduced at 43 +/- 13% and six patients (12%) presented to the cardiac catheterization laboratory in cardiogenic shock. T wenty-nine patients failed to respond to thrombolytic therapy and 16 had co ntraindications for thrombolytics and IIb/IIIa receptor antagonists. Follow ing laser debulking, all patients received adjunct balloon dilation and the n stents were deployed in 83% of the target lesions. Quantitative coronary arteriography (QCA) was performed at an independent core laboratory. Results: Ninety-eight percent laser success and 100%, procedural success we re achieved. By QCA the minimal luminal diameter increased from baseline of 0.7 +/- 0.5 to 1.3 +/- 0.5 mm post-lasing and then to 2.0 +/- 0.6 with bal loon dilation to a final of 3.0 +/- 0.5 mm. Pre-laser percent stenosis diam eter of 77 +/- 17% was reduced to 51 +/- 22% post-laser to 3.0 +/- 17% post -balloon and to a final of 15 +/- 25%. An 83% laser-induced reduction of th rombus burden area was achieved as well as an increase in TIMI flow from ba seline of 1.7 +/- 1.1 to 2.8 +/- 0.4 by laser to a 2.9 +/- 0.4 final. There were no deaths, emergency bypass surgery, cerebral vascular accident, neur ologic injury, or major perforation. In one case, a laser-induced major dis section was successfully treated by stenting. All 50 patients survived the procedure, improved clinically, and were discharged. Conclusion: Application of excimer laser coronary angioplasty is feasible a nd safe in selected patients with acute myocardial infarction who either fa il to respond to thrombolytics or have contraindications to these agents. I ntracoronary thrombus at the target lesion can be successfully dissolved wi th this wavelength laser energy without adverse effect on the procedure res ults. (C) 2001 Wiley-Liss, Inc.