QRS Narrowing Following CRT Implantation: Predictors, Dynamics, and Association with Improved Long-Term Outcome
Daniel Lapidot1, Moshe Rav-Acha1,2, Tali Bdolah-Abram1
1Faculty of Medicine, Hebrew University, Jerusalem 9103102, Israel.
Insights
Cardiac resynchronization therapy (CRT) can lead to QRS narrowing in heart failure patients. Achieving acute QRS narrowing of at least 20 ms after CRT predicts better long-term clinical outcomes.
Area of Science:
- Cardiology
- Electrophysiology
- Heart Failure Management
Background:
- Heart failure (HF) patients with wide QRS often benefit from cardiac resynchronization therapy (CRT).
- However, QRS narrowing does not consistently occur post-CRT.
- Predictors and long-term outcomes associated with QRS narrowing require further investigation.
Purpose of the Study:
- To investigate the incidence and predictors of QRS narrowing following CRT.
- To assess the long-term impact of QRS narrowing on clinical outcomes in HF patients.
Main Methods:
- Retrospective analysis of electrocardiographs from 104 patients undergoing CRT.
- Measurement of QRS duration change pre- and post-implantation.
- Assessment of all-cause mortality and the composite of mortality and HF hospitalizations.
Main Results:
- 53% of patients achieved acute QRS narrowing (≥20 ms) within days.
- Female gender and baseline QRS duration predicted acute narrowing.
- Prolonged baseline PR interval and acute narrowing < 20 ms were independent predictors of adverse composite outcomes.
Conclusions:
- Acute QRS narrowing ≥ 20 ms post-CRT is independently associated with favorable long-term outcomes.
- This acute narrowing may serve as a novel indicator of procedural success in CRT.
- Further research can explore optimizing CRT for QRS narrowing to improve patient prognosis.
Abstract:
Background: Heart failure (HF) patients with wide QRS often benefit from cardiac resynchronization therapy (CRT), although QRS narrowing does not always occur. The current study investigates the incidence and predictors for QRS narrowing following CRT and its long-term impact on clinical outcomes. Methods: Among individuals undergoing clinically indicated CRT, pre-and post-implantation electrocardiographs were meticulously analyzed for QRS duration change. All-cause mortality and the composite of mortality and HF hospitalizations were retrieved. Results: For 104 patients, mean age 67 years, 25% females, QRS narrowed within days by 20.2 ± 24.7 ms. In 55/104 (53%) QRS narrowed by ≥20 ms (“acute narrowing”). Female gender and baseline QRS predicted acute narrowing. Acute narrowing persisted for 1−6 weeks in 18/20 (90%) and 3−12 months in 21/31 (68%) of patients. During the average follow-up of 41 months, 29/104 (28%) died and 50/104 (48%) met the composite outcome. In a multivariable analysis including comorbidities and cardiac history, prolonged baseline PR interval (HR 1.015, CI 1.008−1.021, p < 0.001) and acute narrowing < 20 ms (HR 3.243, CI 1.593−6.603, p = 0.001) were significant and independent predictors for the composite outcome. Conclusions: Post-CRT acute QRS narrowing ≥ 20 ms is independently associated with favorable long-term outcomes and might be considered as a novel measure for procedural success.
