Clinical phenotypes and outcomes associated with improved left ventricular ejection fraction after biventricular
Sameer A Kunte1, Lurdes Y T Inoue2, William T Abraham3
1Division of Cardiology, Duke University School of Medicine, Durham, NC, USA. sameer.kunte@duke.edu.
Insights
Left ventricular ejection fraction (LVEF) improvement after cardiac resynchronization therapy (CRT) is linked to better patient outcomes. Patients with improved LVEF were less likely to have ischemic cardiomyopathy and more likely to have LBBB.
Area of Science:
- Cardiology
- Medical Devices
- Heart Failure Management
Background:
- Not all patients experience left ventricular ejection fraction (LVEF) improvement after cardiac resynchronization therapy (CRT).
- Understanding factors influencing LVEF response is crucial for optimizing CRT outcomes.
Purpose of the Study:
- To identify patient characteristics associated with LVEF improvement post-CRT.
- To evaluate the impact of LVEF improvement on clinical outcomes.
Main Methods:
- Analysis of patients from REVERSE, MADIT-CRT, and BLOCK-HF trials who received CRT.
- Comparison of characteristics between patients with and without LVEF improvement using statistical tests.
- Survival analysis using Kaplan-Meier curves and Cox Proportional-Hazards models to assess time to death or heart failure hospitalization (HFH).
Main Results:
- Of 1065 patients, 85% showed LVEF improvement.
- Improved LVEF was associated with lower rates of ischemic cardiomyopathy (ICM) and higher rates of left bundle branch block (LBBB).
- Patients with improved LVEF had significantly longer time to HFH or death (HR 0.40) and death alone (HR 0.27).
Conclusions:
- LVEF improvement post-CRT is associated with specific patient profiles (less ICM, more LBBB, longer QRS duration).
- Improved LVEF is a significant predictor of better clinical outcomes, including reduced mortality and HFH.
Background:
In some patients who receive a cardiac resynchronization therapy (CRT) device, the left ventricular ejection fraction (LVEF) does not improve.
Methods:
We analyzed patients enrolled in the REVERSE, MADIT-CRT, and BLOCK-HF trials, restricting the analysis to those who received CRT. Characteristics of patients with or without improved LVEF were compared using two sample t-tests and Pearson's chi-square tests. Kaplan-Meier survival curves were constructed to display time-to-event data. A log-rank test was used to compare event rates for patients with or without improved LVEF. Mixed effects Cox Proportional-Hazards models adjusting for covariates were used to analyze time to death or heart failure hospitalization (HFH) and time to death.
Results:
Of 1065 included patients, 75% (802) were men, 87% (793) were White, 11% (118) were Black, and 7% (72) were Hispanic. LVEF improved in 910 (85%) patients and did not in 155 (15%). Patients with an improved LVEF were less likely to have ischemic cardiomyopathy (ICM) (54% vs 76%; p = 0.004), more likely to have LBBB (73% vs 53%; p = < 0.001), and had longer QRS duration (159 vs 150 ms; p = < 0.001). In adjusted analyses, improved LVEF was associated with a longer time to HFH or death (HR 0.40; 95% CI 0.26-0.62; p < 0.001) or death alone (HR 0.27; 95% CI 0.15-0.48; p < 0.001).
Conclusions:
Patients with improvement in LVEF post-CRT implantation are less likely to have ICM and more likely to have LBBB and a longer QRS interval. Improvement in LVEF was associated with better outcomes.
