Impact of paced left ventricular dyssynchrony on left ventricular reverse remodeling after cardiac resynchronization
Anaïs Gauthey1, Erik Willemen2, Joost Lumens2
1Division of Cardiology, Cliniques Universitaires Saint-Luc, Université Catholique de Louvain, Brussels, Belgium.
Insights
Paced left ventricular dyssynchrony (PLVD) during cardiac resynchronization therapy (CRT) implantation predicts poor long-term response. Measuring this electrical dyssynchrony offers valuable insights beyond standard QRS morphology for predicting CRT outcomes.
Area of Science:
- Cardiology
- Electrophysiology
- Medical Device Technology
Background:
- Cardiac resynchronization therapy (CRT) is used to treat heart failure patients with electrical dyssynchrony.
- Predicting long-term CRT response remains a challenge, necessitating improved prognostic markers.
Purpose of the Study:
- To investigate the association between pacing-induced electrical dyssynchrony (PLVD) during CRT implantation and chronic CRT response.
- To determine if PLVD provides incremental predictive value for left ventricular (LV) reverse remodeling.
Main Methods:
- The study included 69 heart failure patients undergoing CRT implantation.
- Intraoperative measurements of LV and RV pacing-induced interlead delays were used to define PLVD.
- CRT response was defined as ≥15% reduction in LV end-systolic volume at 6 months.
Main Results:
- PLVD was associated with ischemic cardiomyopathy and, importantly, with nonresponse to CRT in both univariate and multivariate analyses.
- Atypical left bundle branch block (LBBB) was also independently associated with nonresponse.
- PLVD significantly improved the prediction of LV reverse remodeling when added to models based on QRS morphology.
Conclusions:
- PLVD is a strong independent predictor of reduced LV reverse remodeling after CRT.
- Measuring the electrical substrate during pacing, specifically PLVD, offers additional prognostic value for CRT response prediction.
- These findings highlight the importance of intraoperative electrical assessments for optimizing CRT outcomes.
Introduction:
We investigated whether pacing-induced electrical dyssynchrony at the time of cardiac resynchronization therapy (CRT) device implantation was associated with chronic CRT response.
Methods And Results:
We included a total of 69 consecutive heart failure patients who received a CRT device. Left (LVp-RVs) and right (RVp-LVs) pacing-induced interlead delays were measured intraoperatively and used to determine if there was paced left ventricular (LV) dyssynchrony, defined as present when LVp-RVs is larger than RVp-LVs. CRT response was defined as a reduction in LV end-systolic volume ≥15%, 6 months after implantation. Paced left ventricular dyssynchrony (PLVD) was associated with ischemic cardiomyopathy (ICM) (χ2 : 8; P = .005) but not with QRS morphology nor with pacing lead positions. In a univariate analysis, PLVD (odds ratio [OR], 6.53; 95% confidence interval [CI], 2.2-18.9; P = .001), atypical left bundle branch block (LBBB) (OR, 3.3; 95% CI, 1.2-9.4; P = .022), and ICM (OR, 5.2; 95% CI, 1.6-17; P = .006) were associated with nonresponse. In a multivariate analysis, both PLVD (OR, 9.74; 95% CI, 2.8-33.9; P < .0001) and atypical LBBB (OR, 5.6; 95% CI, 1.5-20.3; P = .009) were independently associated with nonresponse. Adding PLVD to a model based on QRS morphology provided a significant and meaningful incremental value to predict LV reverse remodeling after CRT (χ2 to enter: 8; P < .005). Computer simulations corroborate these findings by showing that, while intrinsic electrical dyssynchrony is a prerequisite, the level of pacing-induced dyssynchrony modulates acute CRT response.
Conclusion:
In addition to the intrinsic electrical substrate, PLVD is strongly associated with less LV reverse remodeling, demonstrating that measuring the electrical substrate during pacing has additional value for prediction of CRT response in an already well-selected patient population.
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