Association between left ventricular global longitudinal strain, health‐related quality of life and functional capacity in chronic kidney disease patients with preserved ejection fraction

AIM: Patients with chronic kidney disease (CKD) have a significant burden of dyspnoea and fatigue in spite having normal left ventricular (LV) ejection fraction (EF). Global longitudinal strain (GLS) can detect subtle changes in LV function. This study aimed to evaluate the relationship between LV function, functional capacity and quality of life (QOL) in CKD patients with preserved EF. METHODS: A cross-sectional study of patients with stage 3/4 CKD (n = 108). Clinical characteristics, biochemical data, functional capacity (6-min walk test (6MWT), timed up and go (TUG) test) and QOL (short form-12 (SF-12v2™) ) were measured. Echocardiogram was used to assess GLS, EF and diastolic function (E/A, e' and E/e'). RESULTS: The mean age was 58.1 ± 9.9 years, 55.6% were men, estimated glomerular filtration rate was 44.8 ± 10.6 mL/min/1.73 m(2), GLS was -18.5 ± 3.6% and 19.4% had impaired GLS (>-16%). Patients with impaired GLS had a significantly shorter 6MWT and slower TUG test compared with patients with preserved GLS. Bivariate analysis showed GLS and E/e' correlated with distance walked in 6MWT (GLS (r = -0.24, P = 0.02); E/e'(r = -0.38, P = 0.002) ). Following adjustment for potential confounders, GLS remained independently associated with 6MWT (model R(2) = 0.37, P < 0.001). Mean physical component summary scores (PCS) and mental component summary scores (MCS) were 43.0 ± 10.2 and 50.9 ± 9.5. There was no cardiac parameter that was independently associated with PCS. However women, lower systolic blood pressure and GLS was associated with lower MCS (model R(2) = 0.30, P < 0.001). CONCLUSION: GLS was associated with measures of functional capacity and QOL in CKD patients with preserved EF.