Acute shock efficacy of the subcutaneous implantable cardioverter‐defibrillator according to the implantation technique

• Published in: Journal of cardiovascular electrophysiology Vol. 32; no. 6; pp. 1695 - 1703
• Main Authors: Francia, Pietro, Adduci, Carmen, Angeletti, Andrea, Ottaviano, Luca, Perrotta, Laura, De Vivo, Stefano, Bongiorni, Maria Grazia, Migliore, Federico, Russo, Antonio Dello, De Filippo, Paolo, Caravati, Fabrizio, Nigro, Gerardo, Palmisano, Pietro, Viani, Stefano, D'Onofrio, Antonio, Lovecchio, Mariolina, Valsecchi, Sergio, Ziacchi, Matteo
• Format: Journal Article
• Language: English
• Published: United States Wiley Subscription Services, Inc 01.06.2021
• Subjects: Arrhythmia; Body mass index; conversion; defibrillation test; Defibrillators; ICD; Multivariate analysis; safety; Shock; subcutaneous; Defibrillation test; ICD; Safety; Subcutaneous; Conversion
• ISSN: 1045-3873; 1540-8167
• DOI: 10.1111/jce.15081

Background The traditional technique for subcutaneous implantable cardioverter defibrillator (S‐ICD) implantation involves three incisions and a subcutaneous (SC) pocket. An intermuscular (IM) 2‐incision technique has been recently adopted. Aims We assessed acute defibrillation efficacy (DE) of S‐ICD (DE ≤65 J) according to the implantation technique. Methods We analyzed consecutive patients who underwent S‐ICD implantation and DE testing at 53 Italian centers. Regression analysis was used to determine the association between DFT and implantation technique. Results A total of 805 patients were enrolled. Four groups were assessed: IM + 2 incisions (n = 546), SC + 2 incisions (n = 133), SC + 3 incisions (n = 111), and IM + 3 incisions (n = 15). DE was ≤65 J in 782 (97.1%) patients. Patients with DE ≤65 J showed a trend towards lower body mass index (25.1 vs. 26.5; p = .12), were less frequently on antiarrhythmic drugs (13% vs. 26%; p = .06) and more commonly underwent implantation with the 2‐incision technique (85% vs. 70%; p = .04). The IM + 2‐incision technique showed the lowest defibrillation failure rate (2.2%) and shock impedance (66 Ohm, interquartile range: 57–77). On multivariate analysis, the 2‐incision technique was associated with a lower incidence of shock failure (hazard ratio: 0.305; 95% confidence interval: 0.102–0.907; p = .033). Shock impedance was lower with the IM than with the SC approach (66 vs. 70 Ohm p = .002) and with the 2‐incision than the 3‐incision technique (67 vs. 72 Ohm; p = .006). Conclusions In a large population of S‐ICD patients, we observed a high defibrillation success rate. The IM + 2‐incision technique provides lower shock impedance and a higher likelihood of successful defibrillation.