HealthDay News — Extravascular implantable cardioverter-defibrillators (ICDs) can be implanted safely, according to a study published online Aug. 28 in the New England Journal of Medicine to coincide with the European Society of Cardiology Congress 2022, held from Aug. 26 to 29 in Barcelona, Spain.
Paul Friedman, M.D., from Mayo Clinic in Rochester, Minnesota, and colleagues conducted a prospective, single-group, nonrandomized premarket global clinical study involving patients with a class I or IIa indication for an ICD who received an extravascular ICD. Successful defibrillation at implantation was the primary efficacy end point, while the primary safety end point was freedom from major system- or procedure-related complications at six months. A total of 356 patients were enrolled.
The researchers found that 98.7 percent of patients had successful defibrillation among the 302 in whom ventricular arrhythmia could be induced and who completed the defibrillation testing protocol. Overall, 94.6 percent of 316 patients were discharged with a working ICD system. At six months, 92.6 percent of patients were free from major system- or procedure-related complications. There were no reports of major intraprocedural complications. Twenty-five major complications were observed in 23 of 316 patients at six months. The success rate of antitachycardia pacing was 50.8 percent. Overall, 29 patients received 118 inappropriate shocks for 81 arrhythmic episodes. During the 10.6-month mean follow-up period, eight systems were explanted without extravascular ICD replacement.
“The results from this study support the hypothesis that substernal placement of electrodes retains the benefit of extravascular placement while providing pause-prevention pacing, antitachycardia pacing, and low-energy defibrillation,” the authors write.
Several authors disclosed financial ties to pharmaceutical and medical device companies, including Medtronic, which funded the study.