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.
Acute shock efficacy of the subcutaneous implantable cardioverter-defibrillator according to the implantation technique / Francia, P.; Adduci, C.; Angeletti, A.; Ottaviano, L.; Perrotta, L.; De Vivo, S.; Bongiorni, M. G.; Migliore, F.; Dello Russo, A.; De Filippo, P.; Caravati, F.; Nigro, G.; Palmisano, P.; Viani, S.; D'Onofrio, A.; Lovecchio, M.; Valsecchi, S.; Ziacchi, M.. - In: JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY. - ISSN 1045-3873. - 32:6(2021), pp. 1695-1703. [10.1111/jce.15081]