Laser in Acute Myocardial Infarction

Abstract

Percutaneous coronary intervention is the preferred contemporary revascularization therapeutic approach for patients who sustain acute myocardial infarction. An integral component of revascularization tools the user -friendly laser offers several unique advantages which enhance the efficacy of PCI in this critical clinical scenario. Basic research demonstrates that the interaction between laser emission and bio tissues uniquely effects two critical pathophysiologic components of AMI: the ruptured atherosclerotic plaque and its accompanying thrombus. The marked precision of the laser energy permits transformation of the irradiated plaque into microscopic particles while its acoustic shock waves mechanically destroy the intra-thrombus’ fibrin fibers system. Consequently, adequate clot dissolution ensues. The laser further improves the treatment of AMI through a significant inhibitory effect on the aggregation kinetics of the platelets adhering to the plaque. Clinical studies of various wavelength lasers in the setting of AMI repeatedly demonstrate laser induced expedient recanalization and adequate restoration of optimal antegrade flow in the infarct related vessel. Technically, the shallow penetration depth of the excimer laser (35–50 μm) indicates that lasing should be performed with emphasis on slow advancement of the irradiating catheter (0.2–0.5 mm/s) enabling proper energy deposition and optimal absorption onto the targeted plaque and thrombus. Laser activation is performed with concomitant saline injections into the vessel, and should only be initiated after complete dye removal from the treated vessel. This avoids unwarranted amplification of the laser generated acoustic shock waves from the contrast dye. Strategically, the precision of laser induced plaque vaporization and effective thrombus dissolution render the placement of distal protection devices unnecessary. Altogether, the use of laser assisted percutaneous revascularization in AMI is associated with very high success rates, especially in complex plaques and heavy thrombus burden, and with a considerably low complication rate.