Arrhythmias & electrophysiology
Inappropriate Shocks From Subcutaneous vs Transvenous Implantable Cardioverter-Defibrillators: Individual Participant Data Meta-Analysis of Randomized Trials
Pooled result · First inappropriate shockResult — go to the resultHazard ratio 1.61 95% CI 1.06–2.45Authors' conclusion
Although first inappropriate shocks were infrequent overall, they were more common with subcutaneous ICDs. First inappropriate shocks due to cardiac oversensing and electromagnetic interference were more common with subcutaneous ICDs, while first shocks due to atrial arrhythmia were more common with transvenous ICDs.
Study context
- Population
- Patients with standard ICD indications (median age 58 years, 21.8% women, 77.7% primary prevention)modified ITT population, PRAETORIAN and ATLAS
- Participants
- 1,342 patients
- Comparison
- Subcutaneous ICD vs transvenous ICD
- Outcome
- Time to first inappropriate shock
- Follow-up
- Median 3.5 years
Methodological detailsCox regression stratified by trial, modified intention-to-treat
- Cox regression stratified by trial
- Modified intention-to-treat
Pooled result
First inappropriate shock
Hazard ratio
1.61
95% CI 1.06–2.45
P = 0.03
By group
Subcutaneous ICD
2.5 per 100 patient-years
Transvenous ICD
1.5 per 100 patient-years
Subcutaneous ICD vs Transvenous ICD
HR 1.61 (95% CI 1.06–2.45); P = 0.03
As reported in the abstract
Further pooled results
| Outcome | HR (95% CI) | P value | |
|---|---|---|---|
| First inappropriate shock by causeCardiac oversensing | 15.07 (3.60–63.15) | P < 0.001 | |
| First inappropriate shock by causeElectromagnetic interference or myopotentials | 8.19 (1.88–35.64) | P = 0.005 | |
| First inappropriate shock by causeAtrial arrhythmia | 0.37 (0.19–0.71) | P = 0.003 | |
| 0.050.21520Hazard ratio (log scale) |
- Proprietary inappropriate-shock-reduction algorithm activated (subcutaneous ICD)
- 77.1%
Original publication
Inappropriate Shocks From Subcutaneous vs Transvenous Implantable Cardioverter-Defibrillators: Individual Participant Data Meta-Analysis of Randomized Trials. J Am Coll Cardiol. Published 10 December 2025. doi:10.
Summarised from the published abstract; every number is checked against it