Objective: Arterial hypertension is an established risk factor for left ventricular hypertrophy (LVH) in the uremic population. However, whether 24-h monitoring is a better predictor of LVH than clinic blood pressure and routine pre-dialysis measurements in these patients is still undefined.
Methods: This problem was studied in 64 nondiabetic hemodialysis patients without heart failure. The echocardiographic study as well as the clinic and 24-h ambulatory blood pressure (BP) measurements were performed during the day off-dialysis. Pre-dialysis arterial pressure was calculated as the average value of the 12 routine recordings taken during the month preceding the study.
Results: In multivariate models, including also sex, body mass index, hematocrit and serum cholesterol, pre-dialysis systolic, diastolic and pulse pressures were the only independent BP determinants of heart geometry. Twenty-four hour ambulatory BP monitoring (ABPM) did add significant (but weak) information to the prediction of left ventricular internal dimension, i.e. it increased by 9% (P = 0.01) the variance already explained by pre-dialysis diastolic BP and other significant covariates. However, 24-h ABPM did not add any significant and independent explanatory information to the corresponding pre-dialysis measurements for the posterior wall and interventricular septum measurements, and for left ventricular mass (-0.6 to +3.9%; average +1.1%).
Conclusions: In dialysis patients, pre-dialysis BP is at least as strong a predictor of left ventricular mass as 24-h ambulatory monitoring. Thus, the average of 12 routine pre-dialysis measurements may be used to predict heart geometry in dialysis patients without any loss of information in comparison with 24-h ambulatory monitoring.