Transmyocardial laser revascularization in combination with coronary artery bypass: Clinical, wall motion and perfusion effects

Background. Transmyocardial laser revascularisation (TMR) is increasingly used in the management of intractable angina in the absence of graftable vessels, however it’s role in combination with coronary artery bypass remains undefined. The aim of this pilot study was to investigate the impact of the combination therapy. Methods. Patients (20) undergoing elective coronary artery bypass surgery with one or more non-graftable coronary arteries were prospectively randomized to either have bypass graft surgery alone (CABG) or bypass graft surgery and transmyocardial revascularization with a holmium — YAG laser to non-graftable areas (CABG+TMR). All patients had exercise tolerance test preoperatively and at 6 and 18 months follow-up. Stress echocardiography was performed on 17 patients 18 months following surgery. Wall motion analysis (1=normal, 2=hypokinesis, 3=akinesis, 4=dyskinesis) using the 16 segment model of the left ventricle and rest and stress perfusion analysis were performed. Results. Both groups of patients were similar in preoperative demographics and operative data. There was no perioperative mortality. There was no difference between the two groups in angina scoring at 6 and 18 months follow-up. Exercise tolerance improved by a mean of 46.8±20.0 seconds per patient in the CABG group and by 199.2±66.5 seconds per patient in the CABG+TMR group (p<0.05) and this was maintained at 18 months (157±46.3 vs 61±39.2 seconds; p<0.05). Regional wall motion score index (WMSI) (total score/number of segments) was calculated in non-revascularizable myocardium treated with TMR and compared to areas that were not lased. Although the WMSI in TMR regions is lower at each stage of dobutamine stress, this does not reach statistical significance. Conclusion. The combination of coronary artery bypass and transmyocardial laser revascularization is safe and improves exercise tolerance in patients in whom complete revascularization cannot be achieved by bypass graft surgery alone. Competition paper presented at the 48th Annual Conference of IACTS at Chennai Feb. 2002