Persistent improvement of ejection fraction in patients with a cardiac resynchronisation therapy defibrillator
Beat Schaer1, Simon Frey1, Christian Sticherling1
1Department of Cardiology, University Hospital of Basel, Switzerland.
Insights
Cardiac resynchronisation therapy with defibrillator back-up (CRT-D) significantly improves left ventricular ejection fraction (LVEF) in heart failure patients. Those achieving LVEF >40% experience substantially lower risks of arrhythmias and defibrillator therapies long-term.
Area of Science:
- Cardiology
- Electrophysiology
- Heart Failure Management
Background:
- Cardiac resynchronisation therapy with defibrillator back-up (CRT-D) is a key treatment for heart failure.
- Left ventricular ejection fraction (LVEF) is crucial for assessing arrhythmia risk.
- CRT-D can improve LVEF, potentially reducing adverse cardiac events.
Purpose of the Study:
- To investigate the relationship between LVEF improvement after CRT-D and subsequent arrhythmic risk.
- To determine if LVEF increase to >40% correlates with fewer appropriate defibrillator therapies.
- To analyze predictors of LVEF improvement in CRT-D patients.
Main Methods:
- Retrospective analysis of 175 CRT-D patients with >2 years follow-up.
- Collection and analysis of serial echocardiography for LVEF measurements.
- Tracking of appropriate defibrillator therapies as primary events.
Main Results:
- 39% of patients achieved sustained LVEF ≥40%.
- Patients with LVEF ≥40% had significantly lower tachyarrhythmic event rates (14% vs. 42.5%).
- Higher baseline LVEF and lack of amiodarone predicted LVEF increase; 5-year survival was higher in improvers (95% vs. 73%).
Conclusions:
- CRT-D effectively increases LVEF in a significant proportion of heart failure patients.
- Achieving LVEF >40% post-CRT-D is associated with reduced long-term arrhythmia burden.
- LVEF response to CRT-D is a critical factor in predicting patient outcomes and survival.
Question Under Study:
Cardiac resynchronisation therapy with defibrillator back-up (CRT-D) is a well-established treatment option for selected heart failure patients. Left ventricular ejection fraction (LVEF), an important risk determinant of life-threatening arrhythmias, can substantially ameliorate with CRT. Our hypothesis was that patients with LVEF improvement to >40% have a lower arrhythmic risk and fewer appropriate defibrillator therapies beyond year one.
Methods:
In this retrospective analysis, all 175 patients with CRT-D implanted from February 2000 to June 2011 and follow-up of >2 years were identified. Every available echocardiography recording was collected. LVEF measurements were grouped to baseline and yearly intervals (±6 months). All appropriate defibrillator therapies were considered events.
Results:
Age at implant was 65 ± 10 years, 86% were male, and 45% patients had ischemic cardiomyopathy. Follow-up was 5.5 ± 2.6 years. LVEF at implant was 25 ± 6%, increased to 34 ± 12% after one year and remained stable thereafter. 39% (69) of patients experienced a sustained increase of LVEF to ≥40%, 14% of them had tachyarrhythmic events (versus 42.5% in those without such increase). Independent predictors for increase were higher baseline LVEF (HR 1.08 (95%-CI 1.04-1.28) per 1% increase) and lack of amiodarone (HR 0.37, 95%-CI 0.16-0.84). With cut-off values of >40%, >45% and >50%, the study hypothesis was refuted in 7%, 2.5% and 5%, respectively. Cumulative 5-year survival was 95% in improvers versus 73% in non-improvers (p <0.001).
Conclusion:
After CRT-D implantation, mean LVEF increased to >40% in 1/3 of patients. These patients experienced significantly fewer arrhythmias during long-term follow-up when compared to patients with persisting LVEF <40%.
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