Is left ventricular hypertrophy a powerful predictor of progression to dialysis in chronic kidney disease?

BACKGROUND: The role of cardiovascular factors in predicting renal outcome has not been extensively elucidated. Herein, we report a prospective evaluation of the impact of left ventricular hypertrophy (LVH) on outcome in non-diabetic patients with chronic kidney disease (CKD). METHODS: We studied 144 patients (99 men; age 62±14 years) with stage 3-4 CKD, with baseline assessment of left ventricular mass index (LVMi) by echocardiography, estimated glomerular filtration rate (eGFR) by MDRD equation, 24-h blood pressure profile and 24-h proteinuria. Combined end point was progression to ESRD requiring dialysis, or death within 5 years. RESULTS: Forty-nine patients (34%) progressed to dialysis, 24 (17%) died, 57 (39%) were dialysis-free after 5 years and 14 were lost to follow-up. Multivariate Cox proportional hazards analysis showed that increased LVMi (HR 1.28, 95% CI 1.17-1.40 for each 10-g/m2 increase, P<0.0001) and reduced eGFR (5% risk increase for each 1-mL/min reduction, P=0.027) were the significant predictors of the combined end point in stage 3 CKD patients, whereas LVMi proved to be the only significant predictor of the combined end point in patients with stage 4 CKD (HR 1.19, 95% CI 1.09-1.31, P<0.0001). The same analysis showed that LVMi was the only significant predictor of progression to dialysis in stage 3 CKD patients (HR 1.42, 95% CI 1.23-1.64 for each 10-g/m2 increase, P<0.0001), while a 20% increase in the risk of progression to ESRD was observed for each 10-g/m2 increase in LVMi (P<0.0001), and a 10% increase for each 1-mL/min reduction in eGFR (P=0.046) in patients with stage 4 CKD. When evaluating the predictive role of LVMi on outcome using AUC-ROC curves, the overall performance of the model including LVMi (AUC 0.877, 95% CI 0.8-0.954) was superior to the model including eGFR (AUC 0.737, 95% CI 0.656-0.817) for the end point of progression to dialysis (P=0.026, Hanley test). CONCLUSIONS: LVH proved to be the strongest predictor of the risk of progression to dialysis in non-diabetic CKD, especially among patients with less advanced renal dysfunction. Regardless of whether it is a simple marker or a pathogenetic factor, LVH encompasses all factors possibly affecting renal and general outcome in CKD patients.