Cardiac denervation after clinical transmyocardial laser revascularization: Short-term and long-term iodine 123-labeled meta-iodobenzylguanide scintigraphic evidence

Abstract

Objectives: This study was designed to investigate whether transmyocardial laser revascularization induces myocardial denervation and to correlate this with myocardial perfusion and clinical status. Methods: Transmyocardial laser revascularization was performed with a Holmium: YAG (n = 3) or xenon chloride excimer laser (n = 5). Preoperative and postoperative iodine 123-labeled meta-iodobenzylguanide SPECT scintigraphy to assess cardiac innervation and perfusion scintigraphy were also performed. Furthermore, New York Heart Association functional angina class and quality of life were assessed. Results: In all patients postoperative iodine 123-labeled meta-iodobenzylguanide SPECT showed significantly decreased uptake and therefore sympathetic myocardial denervation at up to 16 months' follow-up (average preoperative and postoperative summed defect scores of 14.8 ± 5.3 and 24.5 ± 4.2, respectively; P = .00005). In 86% of segments, the decreased meta-iodobenzylguanide uptake could be correlated to the treated area. In all patients angina was reduced by 2 or more classes at 12 months' follow-up, and quality of life improved significantly. Conclusions: Transmyocardial laser revascularization-induced improvement of angina and quality of life can be explained by destruction of nociceptors or cardiac neural pathways, changing the perception of anginal pain.