Heart failure & cardiomyopathiesCohort study
Timing of Cardiac Resynchronization Therapy Following Stable Medical Therapy in Patients With Heart Failure
- Registry-based cohort study
- Swedish ICD and Pacemaker Registry
- multivariable Cox regression
Authors' conclusion
Time from the achievement of SMT to CRT implantation decreased over the study period. Delayed CRT implantation beyond 3 months was associated with higher cardiovascular mortality compared with earlier implantation after GDMT optimization.
Study context
- Population
- Patients with heart failure (HF) on stable medical therapy (SMT) who received cardiac resynchronization therapy (CRT), Swedish ICD and Pacemaker Registry, 2007–2020
- Participants
- 9,409 patients
- Exposure
- Time from SMT to CRT implantation: <3 months or >9 months vs 3-9 months
- Outcome
- Clinical outcomes (mortality and morbidity) by time from SMT to CRT implantation
Main finding
As reported in the abstract
Time from SMT to CRT implantation
- <3 months · CV death, adjusted
- lower risk 9%; P = 0.045
- >9 months · CV death/HF hospitalization, adjusted
- higher risk 13%
- >9 months · CV death, adjusted
- higher risk 12%; P = 0.040
- >9 months · first HF hospitalization, adjusted
- higher risk 11%; P = 0.013
Observational data: associations, not effects.
Further findings
Determinants of time to implantation
- Shorter time: recent HF hospitalization, previous defibrillator, greater use of guideline-directed medical therapy
- Longer time: history of HF >6 months, ischemic heart disease
Original publication
Timing of Cardiac Resynchronization Therapy Following Stable Medical Therapy in Patients With Heart Failure. JACC Heart Fail. Published 20 June 2025. doi:10.1016/j.jchf.2025.102515
Summarised from the published abstract; every number is checked against it