Predictors for cardiac resynchronization therapy response: the importance of QRS morphology and left ventricular lead
Haiyan Lin1, Ying Zhou, Geng Xu
1Department of Cardiology, Second Affiliated Hospital, Zhejiang University, College of Medicine.
Insights
Optimal left ventricular lead placement and non-left bundle branch block (non-LBBB) morphology are key predictors of success for cardiac resynchronization therapy (CRT) in heart failure patients. These factors independently predict improved outcomes and reduced rehospitalization rates.
Area of Science:
- Cardiology
- Medical Devices
- Heart Failure Management
Background:
- Cardiac resynchronization therapy (CRT) improves outcomes for select heart failure patients.
- A significant portion of eligible patients do not respond to CRT.
- Identifying predictors of CRT response is crucial for optimizing patient selection and treatment efficacy.
Purpose of the Study:
- To identify independent predictors of response to cardiac resynchronization therapy (CRT).
- To evaluate the impact of left ventricular lead position and QRS morphology on CRT outcomes.
Main Methods:
- Retrospective analysis of 193 heart failure patients undergoing CRT.
- Evaluation of clinical, electrocardiographic, and echocardiographic parameters pre- and post-CRT.
- Definition of CRT response based on increased left ventricular ejection fraction (LVEF) and absence of heart failure rehospitalization or death.
Main Results:
- Multivariate analysis identified optimal left ventricular lead position (LV-Ps) and non-left bundle branch block (non-LBBB) morphology as independent predictors of CRT response.
- Patients with optimal LV-Ps and LBBB morphology showed significantly lower rates of mortality or heart failure rehospitalization.
- Non-LBBB morphology was associated with a lower likelihood of response (OR 0.15).
Conclusions:
- Optimal left ventricular lead placement is critical for successful CRT.
- Non-left bundle branch block morphology is a significant negative predictor of CRT response.
- These findings can help refine patient selection for CRT and improve treatment outcomes.
Abstract:
Although cardiac resynchronization therapy (CRT) is a well-established treatment for a subset of patients with chronic heart failure, a considerable proportion of eligible patients still fail to benefit from this treatment. The aim of this study was to identify potential independent predictors for being a responder to CRT. A single-center, retrospective analysis was conducted in 193 consecutive patients with heart failure and wide QRS complex who successfully underwent CRT device implantation from January 2006 to October 2012. Clinical characteristics, left ventricular lead position (LV-Ps), electrocardiography and echocardiography were evaluated before and 12 months after CRT. Response to CRT was defined as an absolute increase of ≥ 5% in left ventricular ejection fraction (LVEF) compared with baseline at 12 months after CRT implantation without heart failure rehospitalization or any cause of death. There were 132 responders (68%) and 61 nonresponders (32%). By univariate logistic analysis, the presence of non-left bundle branch block (non-LBBB) and QRS duration, chronic atrial fibrillation (AF), history of ventricular tachycardia (VT), degree of tricuspid regurgitation and left atrium dimension (LAD) at baseline, ΔQRS duration, and LV-Ps were associated with predicting a response to CRT. However, on multivariate analysis, only optimal LV-Ps and presence of non-LBBB remained independently predictive for a CRT response, with an odds ratio of 2.53 (95% confidence interval [CI]: 1.13-5.66, P = 0.023), 0.15(95% CI: 0.05-0.45, P = 0.001), respectively. Kaplan-Meier analysis revealed that patients with nonoptimal LV-Ps or non-LBBB morphology had a significantly higher rate of mortality or heart failure rehospitalization as compared with those with optimal LV-Ps or LBBB morphology (P < 0.05).
