Arrhythmias & electrophysiologyRandomised controlled trial
Cardiovascular Magnetic Resonance to Guide Defibrillator Implantation for Left Ventricular Ejection Fraction (LVEF) of 36% to 50%
- Randomised controlled trial
- open-label
- 18 sites in Australia, Germany and the UK
Authors' conclusion
Implantation of an ICD did not reduce the composite outcome of SCD or HSVA in patients with an LVEF of 36% to 50% and myocardial scar.
Study context
- Population
- Adults with ischaemic or nonischaemic cardiomyopathy, LVEF 36% to 50%, cardiovascular magnetic resonance (CMR)-defined myocardial scar, on guideline-directed medical therapy
- Participants
- 353 adults
- Comparison
- Primary prevention ICD vs implantable loop recorder
- ICDn = 180
- Implantable loop recorder (ILR)n = 173reference
- Primary endpoint
- Sudden cardiac deaths (SCD) or hemodynamically significant ventricular arrhythmia (HSVA) (composite)
Primary result
As reported in the abstract
Hazard ratio
0.76
95% CI 0.37–1.58
Events by treatment group
ICD vs ILR
HR 0.76 (95% CI 0.37–1.58)
Secondary outcomes
| Outcome | ICD | ILR | HR (95% CI) | |
|---|---|---|---|---|
| SCD | 1.7% | 5.8% | 0.26 (0.07–0.95) | |
| HSVA | 6.7% | 3.5% | 1.77 (0.65–4.81) | |
| Primary outcome, by age (prespecified subgroup) · age <70 years | 3.3% | 10.0% | 0.28 (0.09–0.89) | |
| Primary outcome, by age (prespecified subgroup) · age ≥70 years | 16.9% | 7.5% | 2.33 (0.75–7.26) | |
| 0.050.21520Hazard ratio (log scale) |
- Primary outcome, by age (prespecified subgroup): P = .01 for interaction
All-cause mortality, CV mortality, HF hospitalisation
- Similar between groups
Original publication
Cardiovascular Magnetic Resonance to Guide Defibrillator Implantation for LVEF of 36% to 50%. JAMA. Published 28 August 2026. doi:10.1001/jama.2026.17078
Summarised from the published abstract; every number is checked against it