Prevalent left ventricular hypertrophy in the predialysis population: identifying opportunities for intervention

Abstract

Left ventricular hypertrophy (LVH) is present in over 70% of patients commencing dialysis. It is an independent risk factor for cardiac death, which is the cause of death in approximately 45% of patients in dialysis. The prevalence of LVH in patients earlier in the course of renal insufficiency is unknown. As part of a prospective longitudinal study evaluating the progression of comorbid diseases in patients with progressive renal disease, we evaluated LVH. In 175 consecutive patients attending a renal insufficiency clinic we obtained technically adequate echocardiograms and estimated left ventricular mass index (LVMI) using two-dimensional targeted M-mode echocardiography. We calculated LVMI using the American Society of Echocardiography cube formula method regressed to anatomic validation. The population consisted of 115 men and 60 women ranging in age from 20 to 82 years (mean age, 51.5 years). The mean creatinine was 403 +/- 207 micro mol/L (+/-SD), representing a creatinine clearance (Ccr) of 25.5 +/- 17 mL/min. Left ventricular hypertrophy was defined as LVMI greater than 131 g/m(2) in men and greater than 100 g/m(2) in women, and was present in 38.9% of the population studied. We demonstrate that the prevalence of LVH increased with progressive renal decline: 26.7% of patients with Ccr greater than 50 mL/min had LVH, 30.8% of those with Ccr between 25 and 49 mL/min had LVH, and 45.2% of patients with severe renal impairment (Ccr <25 L/min) had LVH (P = 0.05). The mean LVMI was significantly different among the three groups (97.5 g/m(2) v 114.4 g/m(2), respectively; P < 0.001). Univariate analyses revealed that age, hemoglobin, systolic blood pressure and Ccr were significantly different between the groups with and without LVH. The logistic regression model confirmed the findings of the univariate analysis: an increase in age of 5 years was associated with an increase of 3% in risk of LVH (P = 0.0094), as was an increase in systolic blood pressure of 5 mm Hg (P = 0.0018). For each 10 g/L decrease in hemoglobin, the risk of LVH increased by 6% (P = 0.0062), and for each 5 mL/min decline in Ccr the risk increased by 3% (P = 0.0168). We demonstrate the high prevalence of LVH in patients with renal insufficiency prior to the need for dialysis, which is associated with severity of renal impairment, and identify two modifiable factors (systolic blood pressure and anemia) as important predictors of LVH. We suggest that future studies should focus on interventions aimed at attenuating the impact of these factors.