Subcutaneous implantable cardioverter-defibrillators: long-term results of the EFFORTLESS study

Figure 1. Patient flow chart for the EFFORTLESS subcutaneous implantable cardioverter-defibrillator registry.

Figure 2. (A) Kaplan–Meier complication-free rates for overall complications (types I–III) and for complications caused by the subcutaneous implantable cardioverter-defibrillator system (type I). (B) Kaplan–Meier complication-free rates in years 2–5 comparing patients who did and did not experience a complication in year 1.

Figure 3. (A) Pie chart of patients’ experience with inappropriate episodes; number of patients and percent of patients provided. (B) Kaplan–Meier inappropriate shock-free rates for all inappropriate shock, for inappropriate shock due to cardiac oversensing, and for inappropriate shock due to cardiac oversensing of T-waves.

Figure 4. Kaplan–Meier event-free rates in in years 2–5, comparing patients who did and did not experience an event in year 1. (A) Inappropriate shocks. (B) Appropriate shocks. AS, appropriate shock; IAS, inappropriate shock.

Figure 5. Significant multivariable predictors to the risk of receiving appropriate therapy using Anderson–Gill models. Separate models were constructed and are shown for any type of appropriate therapy (A), received and for receiving appropriate therapy for polymorphic ventricular tachycardia/ventricular fibrillation arrhythmias (B), and monomorphic ventricular tachycardia arrhythmias (C). Predictors modelled as continuous variables are indicated with an ‘asterisk’. ARVC, arrhythmogenic right ventricular cardiomyopathy; CHF, congestive heart failure; CI, confidence interval; DCM, dilated cardiomyopathy; HCM, hypertrophic cardiomyopathy; LVEF, left ventricular ejection fraction; NICM, non-ischaemic cardiomyopathy; NYHA, New York Heart Association.

Figure 6. Shock efficacy of appropriate episodes experienced by patients in the EFFORTLESS study. (A) Discrete episodes. The left-sided histogram provides first- and final shock efficacy over the course of the study for all rhythms and for episodes with monomorphic ventricular tachycardia or polymorphic ventricular tachycardia/ventricular fibrillation rhythms. The right-sided histogram provides first- and final shock efficacy for episodes experienced for each post-implant year. The number of episodes, number of patients, mean number of shocks delivered, and maximum number of shocks delivered are listed below each rhythm type (left histogram) and follow-up year (right histogram). Regression analyses show that neither duration of follow-up (P = 0.60) nor rhythm type (P = 0.28) significantly impacted first shock efficacy nor final shock efficacy (P = 0.62 and P = 0.82, respectively) for discrete episodes. (B) Storm episodes. The left-sided histogram provides efficacy over the course of the study for all storm episodes. The right-sided histogram provides shock efficacy for storm episodes experienced for each post-implant year. The numbers of patients and storm episodes are provided for each…

Figure 7. (A) Kaplan–Meir rate of survival for the EFFORTLESS study, 5-year follow-up, for all patients (n = 984) and for primary prevention, left ventricular ejection fraction (LVEF) ≤ 35% (n = 303). (B) Multivariable predictors of mortality. Predictors modelled as continuous variables are indicated with an ‘asterisk’. COPD, chronic obstructive pulmonary disease; LVEF, left ventricular ejection fraction; TV-ICD, transvenous implantable cardioverter-defibrillator.