Release of endothelin-1 from human endocardium after radiofrequency catheter ablation and coronary angioplasty: comparative results.

BACKGROUND Plasma levels of endothelin-1 (ET-1) increase after coronary angioplasty (PTCA) due to endothelial injury during the procedure. ET-1 has been found in human endocardial and myocardial cells. It is not known whether ET-1 increases after thermal injury induced by radiofrequency catheter ablation (RFA). METHODS We determined plasma ET-1 levels at baseline, immediately after, and at 2 and 6 h post-procedure in 31 patients undergoing PTCA and 16 patients undergoing RFA. Patients subjected to diagnostic coronary angiography (n=15) or electrophysiology study (n=13) served as controls. RESULTS Compared to baseline, ET-1 levels increased significantly immediately post-PTCA (55.1+/-20.1 vs. 42.7+/-14.9 pg/ml, p<0.01) and at 2 h post-RFA (98.0+/-11.7 vs. 53.0+/-17.4 pg/ml, p<0.01) and returned to baseline measurements at 2 h post-PTCA and 6 h post-RFA. There was no change of ET-1 levels in the control groups. ET-1 kinetics curve was significantly higher post-RFA compared to post-PTCA (p<0.001). ET-1 immediately post-PTCA correlated with total pressure-time product applied for balloon inflation during the procedure (r=0.56, p<0.01). There was no correlation between ET-1 levels and the number of RFA applications. No patient developed ischemia post-PTCA. There were no complications or arrhythmia recurrences post-RFA. CONCLUSION Endocardial thermal injury incurred during RFA is another mechanism of endothelin increase apart from mechanical injury of the coronary endothelium during PTCA and represents further evidence for the existence of the peptide in human endocardial endothelial and myocardial cells. ET-1 increase is delayed and more pronounced post-RFA compared to post-PTCA. Despite that, it does not seem to have any clinical impact in the immediate post-RFA period.