Background and Aims: The extravascular implantable cardioverter defibrillator (EV ICD) has an extended projected battery longevity compared to the subcutaneous implantable cardioverter defibrillator (S-ICD). This study used modeling to characterize the need for generator changes, long-term complications, and overall costs for both the EV ICD and S-ICD in healthcare systems of various countries . Methods: Battery longevity data were modelled using a Markov model from averages reported in device labelling for the S-ICD and with engineering estimates based on real life usage from EV ICD Pivotal Study patient data to introduce variability. Clinical demographic data of recipients were derived from published literature. The primary outcomes were defined as the number of generator replacement surgeries, complications, and total healthcare system costs due to battery depletion over the expected lifetime of patients receiving EV ICD or S-ICD therapy. A one-way sensitivity analysis of the model was performed for the US healthcare system. Results: Average modelled battery longevity was determined to be 7.3 years for the S-ICD compared to 11.8 years for the EV ICD. The probability of a complication after a replacement procedure was 1.4%, with an operative mortality rate of 0.02%. The use of an EV ICD was associated with 1.4-1.6 fewer replacements on average over an expected patient lifetime as compared to an S-ICD and a 24.3-26.0% reduction in cost. The US sensitivity analysis found use of an EV ICD resulted in a reduction in replacement surgeries of greater than 1 (1.1-1.6) along with 5-figure cost savings in all scenarios ($18,602-$40,948). Conclusion: The longer projected battery life of the EV ICD compared to the S-ICD has the potential to meaningfully reduce long-term morbidity and healthcare resources related to generator changes from the perspective of multiple diverse healthcare systems.

Aims - Although less common, typical atrial flutter (AFL) shares similar pathophysiologic roots with atrial fibrillation (AF). Following successful cavo-tricuspid isthmus ablation using radiofrequency (RF), many patients, however, develop AF in the mid-to-long-term. This study sought to assess whether pulmonary vein isolation (PVI) conducted at the same time as cavo-tricuspid isthmus ablation would significantly modify the AF burden upon follow-up (FU) in patients suffering from typical AFL. Methods - This was a multicenter randomized controlled study involving AFL patients with history of non-predominant AF (1 AF episode only in 67% of population) who were scheduled for CTI RF ablation. Patients were randomly assigned to either undergo cavo-tricuspid isthmus (CTI) ablation alone or CTI plus PVI (CTI+). PVI was performed using cryoballoon technology. An outpatient consultation with ECG and 1-week Holter monitoring was performed at 3, 6 months, 1 year, and 2 years post-procedure. The primary endpoint was AF recurrences lasting more than 30 s at 2 years post-ablation. Results - Of the patients enrolled, 36 were included in each group. At 2-year FU, the AF recurrence rate was significantly higher in the CTI versus CTI+ group (25/36, 69% vs. 12/36, 33% respectively; p<0.001), with similar AFL recurrence rates. There were no differences in quality of life or undesirable events, except for transient phrenic nerve palsy reported from three PVI patients (8.3%). Conclusion - PVI using cryoballoon technology was proven to significantly reduce the AF incidence at 2 years post-CTI-ablation.