Radiofrequency catheter ablation and nerve growth factor concentration in humans

Background: In animal models, expression of nerve growth factor (NGF) is increased after necrotic myocardial injury. Whether radiofrequency (RF) catheter ablation increases NGF expression in humans is unclear. Objectives: The purpose of this study was to determine NGF concentrations in the aorta, coronary sinus, and peripheral veins before and after RF ablation in patients. Methods: We sampled blood from aorta and either great cardiac vein (group 1, N = 18) or proximal (group 2, N = 20) coronary sinus before and after RF ablation. In group 3 (N = 21), peripheral venous blood was sampled before and after RF ablation and then up to postoperative day 7. In group 4 (N = 10), we sampled peripheral venous blood during diagnostic electrophysiologic study. The NGF concentration was determined by enzyme-linked immunosorbent assay. Transcardiac NGF concentration was the difference in NGF concentrations between coronary sinus and aorta. Results: There was no change in transcardiac NGF concentrations in groups 1 and 2. In group 3, the NGF level did not change significantly from before the procedure (17.10 ± 15.80 ng/mL) to immediately after the procedure (14.46 ± 10.36 ng/mL). However, NGF levels increased significantly to 31.24 ± 19.82 ng/mL (N = 21, P <.0001) on postoperative day 1, 26.23 ± 16.89 ng/mL (N = 20, P <.001) on postoperative day 2, and 22.01 ± 11.35 ng/mL (N = 16, P = .003) on postoperative day 3. NGF concentrations did not change significantly in group 4. Conclusion: RF ablation did not result in a detectable increase of transcardiac NGF concentration immediately after the procedure. However, the systemic NGF concentration increased significantly on postoperative days 1 to 3, suggesting that RF ablation resulted in increased NGF expression.