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

Aim: Left ventricular (LV) global longitudinal strain (GLS) is a reliable determinant of LV systolic function. The precise relationship between LV wall stress and serum brain natriuretic peptide (BNP) concentrations in hemodialysis (HD) patients require clarification. BNP levels are raised in patients with end- stage renal disease (ESRD) and could reflect LV impairment amongst HD patients.

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.

Material and Methods: A total of 30 ESRD patients on regular HD – divided into 15 patients with LV ejection fraction (EF) <50% and 15 patients with LV EF > 50% – and 15 age- matched healthy subjects were assessed. LV function and structure were measured using conventional echocardiography, including LV meridional wall stress (LVMWS), LV mass index (LVM I) and two-dimensional speckle tracking echocardiography for determination of LV–GLS. Serum BNP levels were evaluated after HD sessions.

Results: There were significant increases in LVM SW (189.2±81 vs. 72.2±20.6 dynes/cm 2 2 1000, P<0.0001), higher levels of BNP (1238±1085.5 vs. 71±23.4 pg/ml, P<0.0001), w hilst LV–GLS was significantly reduced (15.1±3.1 vs. 20.8±1.7%, P <0.0001) in HD patients, when compared to the controls. Higher values of LVMWS (246.9±67.5 vs. 131.5±43.6 dynes/cm 2 2 1000, P <0.0001) and BNP (1925.4±1087 vs. 550.5±496.5pg/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 0 50% than those with LV EF >50%. Serum levels of BNP were positively correlated with LVM I (r = 0.896, P<0.0001) and LVMW S (r = 0.697, P<0.0001), but negatively correlated with LV–GLS (r = 0 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, being regarded as a crucial hemodynamic biomarker in those patients.