Reassessment of Cardiac Function and Implantable Cardioverter-Defibrillator Use Among Medicare Patients With Low Ejection Fraction After Myocardial Infarction
Authors' conclusion
Although 1-year EF reassessment is associated with increased likelihood of ICD implantation, 1-year ICD implantation rates remain very low even among patients with EF reassessment, regardless of revascularization status.
Study context
- Population
- Medicare-insured patients ≥65 years with ejection fraction (EF) ≤35% during index myocardial infarction (MI) admission, ACTION Registry-GWTG, Jan 2007–Sep 2010
- Participants
- 10,289 patients
- Exposure
- EF reassessment vs no EF reassessment
- Outcome
- Rate of EF reassessment and its association with ICD implantation
- Follow-up
- 1 year
Methodological detailsregistry-based (ACTION Registry-GWTG), Multivariable Cox models with time-dependent EF reassessment, stratified by revascularization status
- Registry-based (ACTION Registry-GWTG)
- Multivariable Cox models with time-dependent EF reassessment, stratified by revascularization status
Main finding
As reported in the abstract
EF reassessment within 1 year
EF reassessment within the next year (all patients)
66.8%
95% CI 65.9–67.8
Implantable cardioverter-defibrillator (ICD) within 1 year among patients with EF reassessment
11%
Observational data: associations, not effects.
Further findings
| Outcome | EF reassessment | No EF reassessment | Adjusted HR (95% CI) | |
|---|---|---|---|---|
| 1-year ICD implantation, revascularized patientsUnadjusted P<0.001 | 12.1% | 2.4% | 10.6 (7.7–14.8) | |
| 1-year ICD implantation, nonrevascularized patientsUnadjusted P<0.001 | 10.0% | 1.7% | 6.1 (4.1–9.2) | |
| 0.050.21520Adjusted hazard ratio (log scale) |
- EF reassessment, revascularized vs nonrevascularized: Revascularized 76.9% (95% CI 75.8–78.0) · Median time to EF reassessment 67 days
- EF reassessment, revascularized vs nonrevascularized: Nonrevascularized 53.7% (95% CI 52.2–55.2) · Median time to EF reassessment 84 days
- EF reassessment, revascularized vs nonrevascularized: P<0.001 for reassessment rate
- EF reassessment, revascularized vs nonrevascularized: P<0.001 for time to reassessment
Original publication
Reassessment of Cardiac Function and Implantable Cardioverter-Defibrillator Use Among Medicare Patients With Low Ejection Fraction After Myocardial Infarction. Circulation. Published 16 November 2016. doi:10.
Summarised from the published abstract; every number is checked against it