Global Longitudinal Strain is a Superior Predictor of All-cause Mortality when Compared to Ejection Fraction in Patients with Mild to Moderate Chronic Kidney Disease

Background: Cardiovascular disease is a major cause of death in chronic kidney disease (CKD). Ejection fraction (EF) is insensitive to minor changes in cardiac function, especially with LV hypertrophy. Global longitudinal strain (GLS) is sensitive to subtle changes in LV function, and is a better predictor of cardiac mortality than EF, but the prognostic value of GLS in CKD is unknown. We sought to (1) compare GLS and EF as predictors of mortality in mild to moderate CKD; (2) characterise relationship of GLS and renal impairment. Methods: Among 397 pts (mean EF 57 ± 12%, GLS −16.5 ± 4.2%) stratified according to estimated glomerular filtration rate (eGFR) [>90, 60–90 and ≤60 ml/min/1.73 m2], 59 died over 5.2 ± 1.5 years. Multivariable regression models were used to evaluate clinical and laboratory factors associated with GLS. Nested Cox regression models were constructed to assess incremental value of GLS and EF for prediction of survival. Results: Chronic kidney disease stage was associated with worsening GLS (p = 0.03). EGFR correlated negatively with GLS (r = −0.15, p = 0.003) but not with EF. GLS was independent associated with gender, previous infarction, serum urate and phosphate (R2 = 0.13, p < 0.0001). All-cause mortality (model χ2 = 22.16) was associated with diabetes (HR=1.90; p = 0.02), eGFR (HR = 0.98; p = 0.004) and GLS (HR = 1.07; p = 0.017). EF did not change the predictive power of the model and was not associated with patient survival. Patients with GLS of ≥ −16% and eGFR of ≤60 ml/min/1.73 m2 had worse overall survival (p = 0.003). Conclusions: Global longitudinal strain was associated with traditional and non-traditional risk factors (urate, phosphate), and was a superior predictor of all-cause mortality compared to EF in CKD.