The prognostic impact of the indexation of left ventricular mass in dialysis patients.

Left ventricular hypertrophy (LVH) is exceedingly frequent in dialysis patients. Cardiac mass is proportional to body size but the influence of various indexation methods has not been studied in patients with end stage renal disease (ESRD). The issue is important because malnutrition and volume expansion would both tend to distort the estimate of LV mass in these patients. In a cohort of 254 patients we assessed prospectively the prognostic impact on all cause mortality and cardiovascular outcomes of LVH values calculated according to two established methods of indexing, either indexed for BSA or for height2.7. When LV mass was analysed as a categorical variable, the height2.7-based method identified a larger number of patients with LVH than the corresponding BSA-based method. One hundred and thirty-seven fatal and non fatal cardiovascular events occurred during the follow-up period. Overall, 90 patients died, 51 of cardiovascular causes. In separate COX’s models both the LV mass/height2.7 and the LV mass/BSA index independently predicted total and cardiovascular mortality (P<0.001). However, the height2.7-based method coherently produced a closer model fitting (P=0.02 or less) than did the BSA-based method. The height2.7 indexation was also important for the sub-categorisation of patients according to the presence of concentric or eccentric LVH because the prognostic value of such sub-categorisation was apparent only when the height2.7 based criterion was applied. In conclusion, LV mass is a strong and independent predictor of survival and cardiovascular events in dialysis patients. The indexation of LV mass by height2.7 provides more powerful prediction of mortality and cardiovascular outcomes than the BSA based method and the use of this index appears appropriate in dialysis patients.