Clinical studies of TMR with the CO₂ laser

This paper reviews the current status of transmyocardial laser revascularization by a carbon dioxide laser. Summary: Since 1990 over 3000 patients worldwide have been treated with a carbon dioxide laser. A nonrandomized phase II trial was completed in 1995. A randomized controlled phase III trial has completed enrollment, and analysis of the follow-up is pending. Methods: In each trial 200 patients with endstage coronary artery disease and severe disabling angina that was not amenable to conventional revascularization were enrolled. Preoperative evaluation included confirmation of angina class and evidence of reversible ischemia based on myocardial perfusion scans. Repeat evaluations were done postoperatively at 3, 6 and 12 months. Results: 80% of the patients showed a significant improvement in angina class status postoperatively and 30% had no angina at one year of follow-up. Concomitant with this there was significantly less ischemia noted on follow-up perfusion scans. Conclusions: Early results from nonrandomized and randomized controlled trials of transmyocardial laser revascularization by carbon dioxide laser indicate that this technique provides angina relief and improved perfusion in patients with end-stage coronary artery disease.