Different Effects of Defibrillator Shocks on the Myocardial Damage Between Subcutaneous and Transvenous Implantable Cardioverter‐Defibrillators
Takahide Kadosaka, Masaya Watanabe, Motoki Nakao, Taro Koya, Hikaru Hagiwara, Hiroyuki Gibo, Taro Temma, Kazuya Mizukami, Hisashi Yokoshiki, Toshihisa AnzaiABSTRACT
Background
Although the implantable cardioverter defibrillators (ICD) are the only established treatment to prevent sudden cardiac death, previous studies reported that those who receive shock therapies, whether appropriate or inappropriate, have a higher risk of death. However, the difference in the influence of shock therapies between via Transvenous‐ICD (TV‐ICD) and Subcutaneous‐ICD (S‐ICD) has not been adequately examined. We aimed to investigate the influence of shocks on myocardium in patients with TV‐ICD and S‐ICD.
Methods
We enrolled consecutive patients who received a defibrillator or transvenous pacemaker (TV‐PM) implantation between November 2020 and March 2024. A total of 74 patients were included in this study and divided into three groups: patients with TV‐ICD with defibrillation testing (DFT) (TV‐DFT, 27 patients), those with transvenous devices implanted without DFT (TV‐no DFT, 25 patients) and those with S‐ICD (22 patients).
Results
Delta log troponin‐I (the difference of serum troponin‐I levels between baseline and after implantation) was significantly increased in TV‐DFT group. In patients with TV‐ICD (46 patients), Delta log troponin‐I was significantly correlated with total shock joules. In the multivariable linear regression analysis, a value of total shock joules was independently associated with delta troponin‐I.
Conclusion
Elevation of serum troponin‐I was associated with the TV‐ICD shocks and correlated with the total shock energy, but not with S‐ICD shocks. Our results suggest that TV‐ICD shocks are associated with greater myocardial injury compared to S‐ICD shocks, and that total shock energy is an important determinant of the extent of myocardial damage.