Nonspecific intraventricular conduction delay predicts the prognosis of dilated cardiomyopathy
Yong Yuan1,2, Kai Yang1, Qianjun Liu3
1Department of Magnetic Resonance Imaging, Cardiovascular Imaging and Intervention Center, State Key Laboratory of Cardiovascular Disease, National Center for Cardiovascular Diseases, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100037, China.
Insights
Nonspecific intraventricular conduction delay (NSIVCD) is an unfavorable prognostic marker in dilated cardiomyopathy (DCM) patients. This finding is independent of other key clinical factors, highlighting the importance of NSIVCD in DCM prognosis.
Area of Science:
- Cardiology
- Electrophysiology
- Cardiovascular Imaging
Background:
- Left bundle branch block (LBBB) is a known adverse prognostic indicator in dilated cardiomyopathy (DCM).
- Prognostic data for nonspecific intraventricular conduction delay (NSIVCD) in DCM are limited and conflicting.
Purpose of the Study:
- To evaluate the prognostic significance of NSIVCD in patients with DCM.
- To compare the outcomes of DCM patients with NSIVCD to those with LBBB, RBBB, and no intraventricular conduction delay (IVCD).
Main Methods:
- 548 DCM patients undergoing cardiovascular magnetic resonance imaging (CMR) were categorized into four groups: LBBB, RBBB, NSIVCD, and no IVCD.
- Patients were followed for a median of 58 months for composite endpoints including cardiovascular death, heart transplantation, and malignant arrhythmias.
- Kaplan-Meier analysis and Cox proportional hazards regression were used to analyze associations between IVCD patterns and outcomes.
Main Results:
- Patients with NSIVCD and LBBB exhibited higher event rates compared to those without IVCD; RBBB did not show a significant difference.
- Multivariate Cox regression identified LBBB, NSIVCD, NYHA class, LVEF, LVEDDI, LGE%, and GLS as independent predictors of adverse outcomes in DCM.
- The average age of the cohort was 46 ± 15 years, with 72.6% males.
Conclusions:
- Nonspecific intraventricular conduction delay (NSIVCD) is an independent unfavorable prognostic marker in DCM patients.
- This prognostic value of NSIVCD holds true irrespective of other clinical parameters like LVEDDI, NYHA class, LVEF, LGE%, and GLS.
- The findings underscore the clinical importance of identifying and assessing NSIVCD in the management of DCM.
Purpose:
Left bundle branch block (LBBB) has been confirmed to be independently associated with adverse outcomes in dilated cardiomyopathy (DCM). However, prognostic data on nonspecific intraventricular conduction delay (NSIVCD) are still limited and conflicting. We aimed to evaluate the prognosis of DCM with NSIVCD.
Methods:
A total of 548 DCM patients who underwent cardiovascular magnetic resonance imaging (CMR) from January 2016 to December 2017 were consecutively enrolled. The cohort was divided into four groups: 87 with LBBB, 27 with RBBB, 61 with NSIVCD, and 373 without intraventricular conduction delay (IVCD). After a median follow-up of 58 months (interquartile range: 47-65), 123 patients reached the composite endpoints, which included cardiovascular death, heart transplantation, and malignant arrhythmias. The associations between different patterns of IVCD and the outcomes of DCM were analysed by Kaplan‒Meier analysis and Cox proportional hazards regression analysis.
Results:
Of 548 DCM patients, there were 398 males (72.6%), and the average age was 46 ± 15 years, ranging from 18 to 76 years. In Kaplan‒Meier analysis, patients with NSIVCD and LBBB showed higher event rates than patients without IVCD, while RBBB patients did not. By multivariate Cox regression analysis, LBBB, NSIVCD, NYHA class, left ventricular ejection fraction (LVEF), indexed left ventricular end-diastolic diameter (LVEDDI), percentage of late gadolinium enhancement mass (LGE%), and global longitudinal strain (GLS) were found to be independently associated with the outcomes of DCM.
Conclusions:
In addition to LBBB, NSIVCD was an unfavourable prognostic marker in patients with DCM, independent of LVEDDI, NYHA class, LVEF, LGE%, and GLS.
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