Elsevier

The American Journal of Cardiology

Volume 137, 15 December 2020, Pages 39-44
The American Journal of Cardiology

Predicting the Development of Reduced Left Ventricular Ejection Fraction in Patients With Left Bundle Branch Block

https://doi.org/10.1016/j.amjcard.2020.09.034Get rights and content

Left bundle branch block (LBBB) increases the likelihood of developing reduced left ventricular (LV) ejection fraction (EF) but predicting which patients with LBBB and normal LVEF will develop decreased LVEF remains challenging. Fifty patients with LBBB and normal LVEF were retrospectively identified. Clinical, electrocardiographic, and echocardiographic variables were compared between patients who developed a decreased LVEF and those who did not. A total of 16 of 50 patients developed reduced LVEF after 4.3 (SDā€Æ=ā€Æ2.8) years of follow-up. Baseline patient and electrocardiographic variables were similar between patients who did and did not develop decreased LVEF. Baseline LVEF was lower in patients who developed decreased LVEF than in those who did not (51.9% [SDā€Æ=ā€Æ2.2%] vs 54.9% [SDā€Æ=ā€Æ4.4%], p <0.01). Diastolic filling time (DFT) accounted for a significantly smaller percentage of the cardiac cycle in patients who developed decreased LVEF than in those who did not (35.9%, [SDā€Æ=ā€Æ6.9%] vs 44.4% [SDā€Æ=ā€Æ4.5%] p <0.01). In univariable logistic regression, DFT had a C-statistic of 0.86 (p <0.0001) for prediction of development of decreased LVEF. In conclusion, patients in whom DFT accounted for <38% of the cardiac cycle had a relative risk of developing decreased LVEF of 7.0 (95% confidence interval 3.0 to 16.0) compared to patients with DFT accounting for ā‰„38% of the cardiac cycle.

Section snippets

Methods

This study complied with the Declaration of Helsinki and was approved by the Duke Institutional Review Board. The study cohort was identified in the Duke Echocardiographic Laboratory Database8,9 after linking to the electrocardiogram database. The study population consisted of patients aged ā‰„18 years with a standard 12 lead electrocardiogram obtained within 30 days of a clinically obtained echocardiogram and a follow-up echocardiogram performed >6 months later. Baseline echocardiograms were

Results

A total of 50 patients fulfilled eligibility criteria and were included in the analysis (Figure 1), 16 patients developed decreased LVEF and 34 patients did not. The mean time to follow-up echocardiogram was 4.3 years (SDā€Æ=ā€Æ2.8 years) in both patients with decreased LVEF and those without unchanged follow-up LVEF, p = 0.95 for difference between groups. Patients who developed decreased LVEF had a mean follow-up LVEF of 37.0% (SDā€Æ=ā€Æ8.1%) with a mean LVEF change of āˆ’14.9% (SDā€Æ=ā€Æ8.3%) whereas

Discussion

In our cohort of 50 patients with LBBB and normal LVEF, 16 (32%) developed decreased LVEF. Baseline patient characteristics were not associated with the risk of developing decreased LVEF, however, baseline echocardiographic variables including lower LVEF, longer ICT and IRT, and shorter DFT were associated with the risk of developing decreased LVEF.

The current ACCF/HRS/AHA/ASE/HFSA/SCAI/SCCT/SCMR appropriate use criteria statement supports the use of CRT as a class I indication for treatment of

Disclosures

Dr. Atwater receives research support from Boston Scientific, Abbott Medical and Honoraria from Abbott Medical, Medtronic, and Biotronik. Dr. Sze has received research funding from Medtronic. Dr. Black-Maier receives research support from Boston Scientific. Dr. Loring is supported in part by an NIH T32 training grant (#5T32HL069749) and receives research support from Boston Scientific, and serves as a consultant to Huxley Medical. All other authors have reported no relevant disclosures to this

References (25)

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  • Association between vectorcardiographic QRS area and incident heart failure diagnosis and mortality among patients with left bundle branch block: A register-based cohort study

    2021, Journal of Electrocardiology
    Citation Excerpt :

    Patients with left bundle branch block (LBBB) have a poor prognosis due to increased risks of heart failure (HF) and mortality [1ā€“4]. LBBB causes ventricular dyssynchrony that leads to insufficient cardiac contractility and abnormal left ventricular filling, resulting in reduced cardiac function [5,6]. Current clinical guidelines recommend using QRS morphology and duration based on the standard 12lead electrocardiogram (ECG) for assessment of ventricular dyssynchrony and thereby patient selection for cardiac resynchronization therapy (CRT) implantation in case of ongoing HF symptoms [7].

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