Clinical utility of left ventricular strain, wall stress and serum brain natriuretic peptide levels in chronic hemodialysis patients

BACKGROUND: Left ventricular (LV) global longitudinal strain (GLS) reliably assesses LV systolic function. The precise relation between LV wall stress and serum Brain natriuretic peptide (BNP) concentrations in hemodialysis (HD) patients needs to be clarified. BNP levels are raised in patients with end-stage renal disease (ESRD) and could reflect LV impairment among HD patients. AIM OF THIS WORK: This study sought to evaluate the clinical utility of LV-GLS, wall stress and serum BNP levels in chronic HD patients. The correlations between BNP levels with both LV wall stress and LV-GLS were assessed. PATIENTS AND METHODS: 30 ESRD patients on regular HD {categorized into 15 patients with LV ejection fraction (EF) ≤ 50% and 15 patients with LV EF > 50%} and 15-age matched healthy subjects were included. LV function and structure were assessed by conventional echocardiography including LV meridional wall stress (LVMWS), LV mass index (LVMI) and 2-dimensional speckle tracking echocardiography for determination of LV-GLS. Serum BNP levels were evaluated after HD session. RESULTS: There were significant increase of LVMSW (189.2 ± 81 vs. 72.2 ± 20.6 dynes/cm(2) × 1000, P < 0.0001), higher levels of BNP (1238 ± 1085.5 vs. 71 ± 23.4 pg/ml, P < 0.0001) while LV-GLS was significantly reduced (15.1 ± 3.1 vs. 20.8 ± 1.7%, P < 0.0001) in HD patients compared to controls. Higher values of LVMWS (246.9 ± 67.5 vs. 131.5 ± 43.6 dynes/cm(2) × 1000, P < 0.0001) and BNP (1925.4 ± 1087 vs. 550.5 ± 496.5 pg/ml, P < 0.0005) with further impairment of LV-GLS (13.8 ± 2.5 vs. 16.4 ± 5.4%, P < 0.05) were found in patients with LV EF ≤ 50% than those with LV EF > 50%. Serum levels of BNP were positively correlated with LVMI (r = 0.896, P < 0.0001) and LVMWS (r = 0.697, P < 0.0001) but negatively correlated with LV-GLS (r = −0.587, P < 0.0001). CONCLUSION: LV-GLS and LVMWS are useful imaging markers for detection of LV dysfunction in HD patients. Serum BNP level is influenced by LV structural abnormalities and suggested to be a crucial hemodynamic biomarker in those patients.