Intermediate-term clinical outcome following transmyocardial laser revascularization in patients with refractory angina pectoris

Background - This study was conducted to examine the intermediate-term clinical outcomes in patients with refractory angina pectoris treated with transmyocardial laser revascularization (TMR) at our institution. TMR is an alternative surgical technique for the treatment of myocardial ischemia and angina pectoris not amenable to conventional percutaneous or surgical revascularization. Limited data exist evaluating the natural history and duration of clinical improvement in angina pectoris following TMR. Methods and Results -Thirty-four patients with severe coronary artery disease unsuitable for treatment with standard revascularization techniques underwent TMR in myocardial regions determined to be ischemic by preoperative SPECT ²⁰¹Tl perfusion imaging following dipyridamole stress. Patients were assessed postoperatively at 3, 6, and 12 months for clinical outcomes including death, myocardial infarction, functional class of angina pectoris, and hospitalizations for unstable angina. Myocardial perfusion imaging by ²⁰¹Tl scintigraphy was also assessed at these temporal end points. Overall mortality at I year was 14.7% (n=5). Nonfatal myocardial infarction occurred in 3 patients (8.8%). Among the patients with complete 12-month follow-up (n =27), mean anginal class improved from 3.5±0.5 pre-TMR to 2.8 ± 0.7 and 2.5±0.7 at 3 and 6 months, respectively, and 2.8±0.9 at 12 months. Overall improvement in angina pectoris was sustained at 1 year by at least one functional class in 50% of patients. Mean hospitalizations per year for unstable angina declined from 2.4±1.6 pre-TMR to 1.7±-2.0 post-TMR (P=0.01). There was no significant improvement in perfusion by SPECT ²⁰¹Tl imaging at any temporal end point post-TMR. Conclusions - Despite the lack of demonstrable improvement in perfusion by SPECT ²⁰¹Tl imaging, TMR improved the functional class of angina pectoris in patients with end stage coronary artery disease to a modest degree. Although the maximal benefit in symptoms occurred at 6 months post-TMR, mild sustained clinical improvement above baseline was evident in 50% of patients at 1 year.