M. Frey’s research while affiliated with University of Freiburg and other places

Does transmyocardial laser revascularization (TMLR) as a new surgical technique for treating patients with otherwise intractable angina pectoris improve myocardial perfusion or contractility? Sixty-seven patients transferred for TMLR were evaluated by clinical evaluation, treadmill stress testing, echocardiography, ventriculography, and hybrid positron emission tomography preoperatively and in patients treated with TMLR at 6 and 12 month follow up. Hemodynamic assessment and clinical evaluation were performed perioperatively. In 28/67 cases (42%) CABG, in 9/67 patients (13%) CABG in combination with TMLR (combined group), and in 30/67 patients (45%) only TMLR (sole group) were performed. Perioperative mortality in the sole group was 13%, in the combined group zero, and in the CABG group 11%. In all groups a significantly improved clinical status (p < or = 0.01) 1 week postoperatively and in TMLR groups also at 6 and 12 months was observed. In the TMLR groups treadmill tolerance (p < 0.05) improved, although function, perfusion, and metabolism did not change significantly at the 6 and 12 month follow up. TMLR significantly improves clinical status and treadmill stress tolerance, but does not change function, perfusion, and metabolism.

Objectives: For patients with severe angina, in whom PTCA or CABG is impossible, a new Laser treatment technique (transmyocardial laser revascularization=TMLR) has been used for revascularization. Methods: Between 9/95 and 2/96 TMLR was performed in 14 male patients (mean age 68.0±5.5 years) who had demonstrable ischemia in viable myocardium. Preoperative 11/14 patients (79%) had an MI and 9/14 patients (64%) underwent previous CABG. LV-EF was 46% on average. The mean Canadian Cardiovascular Society (CCS) angina class was 3.6±0.6. All patients are followed by PET, 201-TI-SPECT or Tc99m-Sestamibi scan, echo, exercise tolerance test, clinical status and ventriculography - preoperative, 4 and 12 months after operation. Perioperative Swan Ganz catheter - investigations were performed. Results: In 4/14 patients (36%) a combined procedure (TMLR and aortocoronary bypass operation) has been done. In these cases 12.3 microchannels and in the solitary procedures (TMLR in 64%) 28 microchannels per patient (on average) were achieved. One week after operation (n=13) mean CCS angina class was to 2.5±0.8 (p<0.05). At 4 month, (n=6), mean CCS angina class decreased to 1.8±0.6 (p<0.05). Resting perfusion and metabolic, echocardiographic and MUGA-scan- studies did not represent statistically significant change over baseline (p=ns). In contrast average treadmill tolerance and the average maximal exertion were both significantly increased. Conclusions:This study indicates that the treatment with TMLR relieves symptoms and increases treadmill tolerance. Further systematic follow-up will show if myocardial perfusion and contractility will improve. Experimental porcine studies to explain the mechanism of TMLR are in progress.