Incremental prognostic value of assessing left ventricular myocardial mechanics in patients with chronic systolic heart failure

Objectives: This study sought to examine the ability of left ventricular (LV) global longitudinal strain (GLS) to assess disease severity in patients with chronic systolic heart failure (HF).

Background: Left ventricular GLS is a sensitive measure of LV mechanics. Its relationship with standard clinical markers and long-term adverse events in chronic systolic HF is not well established.

Methods: In 194 chronic systolic HF patients, we performed comprehensive echocardiography with assessment of GLS by velocity vector imaging averaged from apical 4-chamber and 2-chamber views. Death, cardiac transplantation, and HF hospitalization were tracked for 5 years.

Results: In our study cohort (age 57 ± 14 years, left ventricular ejection fraction [LVEF] 26 ± 6%, median N-terminal pro-B-type natriuretic peptide [NT-proBNP] 1,158 pg/ml), the mean GLS was -7.1 ± 3.3%. The GLS worsened with increasing New York Heart Association functional class (rank-sum p < 0.0001) and higher NT-proBNP (r = 0.42, p < 0.0001). The GLS correlated with LV cardiac structure (LV mass index: r = 0.35, p < 0.0001; LV end-diastolic volume index: r = 0.43, p < 0.0001) and LVEF (r = -0.66, p < 0.0001). A lower magnitude of GLS was associated with worsening LV diastolic function (E/e' septal: r = 0.33, p < 0.0001), right ventricular (RV) systolic function (RV s': r = -0.30, p < 0.0001), and RV diastolic function (RV e'/a': r = 0.16, p = 0.033). GLS predicted long-term adverse events (hazard ratio: 1.55, 95% confidence interval: 1.21 to 2.00; p < 0.001). Worsening strain (GLS ≥-6.95%) predicted adverse events after adjustment for age, sex, ischemic etiology, E/e' septal, and NT-proBNP (hazard ratio: 2.04, 95% confidence interval: 1.09 to 3.94; p = 0.025) and age, sex, ischemic etiology, and LVEF (hazard ratio: 2.15, 95% confidence interval: 1.19 to 4.02; p = 0.011).

Conclusions: In chronic systolic HF, worsening LV GLS is associated with more severe LV diastolic dysfunction and RV systolic and diastolic dysfunction, and provides incremental prognostic value to LVEF.