Improved myocardial function after transmyocardial laser revascularization according to cine magnetic resonance in a porcine model.

Abstract

This study was undertaken to demonstrate that transmyocardial laser revascularization of hypoperfused myocardium improves regional and global myocardial function. Cine magnetic resonance imaging was used to monitor regional wall thickening (in millimeters) and cardiac output (in milliliters per kilogram per minute). Cine magnetic resonance imaging was performed before and 8 weeks after transmyocardial laser revascularization was applied to the hypoperfused lateral wall of the left ventricle (target area) in a porcine model (n = 9, transmyocardial laser revascularization group). A second group of animals was left untreated (n = 8, control group). Regional wall thickening in the target area improved after transmyocardial laser revascularization (0.7 +/- 0.3 mm to 3.7 +/- 1.9 mm, P <.02) and was significantly higher (P <.01) after transmyocardial laser revascularization than in the control group, in which it did not improve (0.5 +/- 0.6 mm to 0.5 +/- 1.2 mm). Accordingly, cardiac output and microsphere-derived myocardial blood flows were significantly higher than in the control group (P <.01), and the amount of triphenyltetrazolium chloride-stained myocardium was lower (P <.01). Cine magnetic resonance imaging demonstrates improved global and regional myocardial function after transmyocardial laser revascularization in a porcine model.