Assessment of three-dimensional (3-D) left ventricular ejection fraction and speckled tracking echocardiographic strain parameters in non-ischemic left bundle branch block (LBBB) patients and their association with cardiovascular events – A prospective observational study

Objective

To investigate the association between three-dimensional (3-D) left ventricular ejection fraction (LVEF) and various speckle tracking echocardiographic (STE) strain parameters in non-ischemic left bundle branch block (LBBB) patients with major adverse cardiovascular events (MACE) during a one-year follow-up phase.

Method

A total of 50 patients with non-ischemic LBBB were assessed using various parameters of 3-D echocardiography. They were compared with their same-age and sex control group and then followed up with repeat 3-D echocardiography for MACE for one year.

Results

Composite outcomes were seen in (n = 11 [22 %], including cardiovascular mortality (n = 2 [4.0 %]) and hospitalization for heart failure (n = 9 [18.0 %]). Mean values of the left ventricle (LV) global longitudinal (GLS), circumferential (GCS), and radial (GRS) strains were −14.4 ± 5.6, −14.3 ± 5.8, and 15.3 ± 5.9 respectively in the study cases. Initial GLS values were significantly impaired among those who had clinical events (−9.2 vs −15.9). Also, significant worsening of GLS (p value < 0.001) was seen in patients with composite outcomes on follow-up. Cut-off values in receiver operating characteristic analyses for composite outcomes were: GLS more than −13.5, GCS more than −12.5, and GRS less than 14.5. Intra-class correlations for both intra-observer and inter-observer variability were found to be good.

Conclusion

Impaired LV GLS and low 3-D LVEF are significantly associated with the occurrence of MACE in patients with non-ischemic LBBB. This strong association of LV GLS with outcomes can aid in risk stratification, prognostication, and clinical decision-making in non-ischemic LBBB.