Implant and Midterm Outcomes of the Subcutaneous Implantable Cardioverter-Defibrillator Registry
The EFFORTLESS Study
BACKGROUND The subcutaneous implantable cardioverter-defibrillator (S-ICD) was developed to defibrillate ventricular
arrhythmias, avoiding drawbacks of transvenous leads. The global EFFORTLESS S-ICD (Evaluation oF FactORs
ImpacTing CLinical Outcome and Cost EffectiveneSS of the S-ICD) registry is collecting outcomes in 985 patients during a
OBJECTIVES The primary goal of the EFFORTLESS registry is to determine the safety of the S-ICD by evaluating complications and inappropriate shock rate.
METHODS This is the first report on the full patient cohort and study endpoints with follow-up $1 year. The predefined endpoints are 30- and 360-day complications, and shocks for atrial fibrillation or supraventricular tachycardia. RESULTS Patients were followed for 3.1 ± 1.5 years and 82 completed the study protocol 5-year visit. Average age was 48 years, 28% were women, ejection fraction was 43 ± 18%, and 65% had a primary prevention indication. The S-ICD system and procedure complication rate was 4.1% at 30 days and 8.4% at 360 days. The 1-year complication rate trended toward improvement from the first to last quartile of enrollment (11.3% [quartile 1]) to 7.8% [quartile 2], 6.6% [quartile 3], and 7.4% [quartile 4]; quartile 1 vs. quartiles 2 to 4; p ¼ 0.06). Few device extractions occurred due to need for antitachycardia (n ¼ 5), or biventricular (n ¼ 4) or bradycardia pacing (n ¼ 1). Inappropriate shocks occurred in 8.1% at 1 year and 11.7% after 3.1 years. At implant, 99.5% of patients had a successful conversion of induced ventricular tachycardia or ventricular fibrillation. The 1- and 5-year rates of appropriate shock were 5.8% and 13.5%, respectively. Conversion success for discrete spontaneous episodes was 97.4% overall.
CONCLUSIONS This registry demonstrates that the S-ICD fulfills predefined endpoints for safety and efficacy. Midterm performance rates on complications, inappropriate shocks, and conversion efficacy were comparable to rates observed in transvenous implantable cardioverter-defibrillator studies.
|Keywords||appropriate therapy, inappropriate therapy, leadless, primary prevention, secondary prevention, ventricular arrhythmias|
|Persistent URL||dx.doi.org/10.1016/j.jacc.2017.06.040, hdl.handle.net/1765/101057|
|Journal||Journal of the American College of Cardiology|
|Note||on behalf of the EFFORTLESS Investigator Group|
Boersma, L, Barr, C.S, Knops, R.E, Theuns, D.A.M.J, Eckardt, L, Neuzil, P, … Lambiase, P.D. (2017). Implant and Midterm Outcomes of the Subcutaneous Implantable Cardioverter-Defibrillator Registry. Journal of the American College of Cardiology, 70(7), 830–841. doi:10.1016/j.jacc.2017.06.040