Left atrial (LA) enlargement predicts adverse cardiovascular events in patients with chronic kidney disease (CKD). The aim of our study was to evaluate the value of LA reservoir strain, a novel measure of LA function, as a prognostic marker for adverse renal outcomes. A total of 280 patients (65.8 ± 12.2years, 63% male) with stable Stage 3 and 4 CKD without prior cardiac history were evaluated with transthoracic echocardiography and prospectively followed for up to 5 years. The primary end point was progressive renal failure, which was the composite of death from renal cause, end-stage renal failure and/or doubling of serum creatinine. Over a mean follow up of 3.9 ± 2.7years, 56 patients reached the composite endpoint. By log rank test, older age, lower baseline eGFR, anemia, diabetes mellitus, higher urinary albumin/creatinine ratio, number of antihypertensive medications, higher indexed left ventricular mass, larger LA volumes, and impaired LA reservoir strain were significant predictors of the composite outcome (p <0.01 for all). Multi-variable Cox regression analysis found LA reservoir strain, eGFR, number of antihypertensive medications and urinary albumin/creatinine ratio were independent predictors for progressive renal failure (p <0.01 for all). Impaired LA reservoir strain was associated with a 2.5-fold higher risk of the composite outcome (HR 2.51, 95% CI 1.19 to 5.30, p = 0.02) and was the only echocardiographic parameter that predicted progressive renal failure independent of established clinical risk factors for end-stage renal failure. Its utility requires validation in high risk CKD patients with cardiac disease.
Gary C H Gan, Aditya Bhat, Krishna K Kadappu, Fernando Fernandez, Kennith H Gu, Henry H L Chen, Suzanne Eshoo, Brian Nankivell, Liza Thomas