Magnetic resonance imaging demonstrates improved regional systolic wall motion and thickening and myocardial perfusion of myocardial territories treated by laser myocardial revascularization

Objectives This study was designed to investigate the use of magnetic resonance (MR) functional and perfusion imaging to evaluate laser myocardial revascularization (LMR). Background Most clinical studies of LMR have shown improvements in angina class and exercise capacity, with minimal or absent improvements in myocardial perfusion and function. Methods Fifteen patients who underwent percutaneous Biosense-guided holmium:yttrium aluminum garnet LMR to areas of viable but ischemic myocardium were followed clinically and underwent functional and perfusion MRI at baseline, 30 days and 6 months. Results The mean age was 64 ± 11 years; four patients were women. The ejection fraction was 47.4 ± 14.0%. Angina class at baseline was 3.4 ± 0.6 and improved to 2.5 ± 1.4 at six months (p = 0.054). Exercise time at baseline was 298 ± 97 s and increased to 350 ± 95 s at 30 days and 365 ± 79 s at six months, P = 0.04. There were no significant changes in nuclear perfusion scans. Although MR determined that resting radial motion and thickening of the target wall were significantly less than normal at baseline (p < 0.001), they improved significantly during follow-up (wall thickening: baseline, 30.6 ± 11.7%; day 30, 41.2 ± 13.3% and day 180, 44.2 ± 11.9%, P = 0.01). The size of the underperfused myocardial area was 14.5 ± 5.4% at baseline and was reduced to 6.3 ± 2.8% at 30 days and 7.7 ± 3.7% at 6 months (p < 0.001). Conclusions This small phase I, open-label, uncontrolled study of MR functional and perfusion imaging in patients undergoing Biosense-guided LMR suggests a beneficial effect of this treatment strategy on myocardial function and perfusion. The efficacy of Biosense-guided LMR is being evaluated in a large phase II, randomized, blinded placebo-controlled trial with an MRI substudy (DIRECT).