Reduced blood pressure diurnal variability as a risk factor for progressive left ventricular dilatation in hemodialysis patients.

Cardiovascular mortality places a considerable burden on chronic renal replacement therapy programs. Left ventricular hypertrophy (LVH) increases the risk for cardiovascular mortality. Risk factors for LVH in the dialysis population are numerous and include arterial distensibility, hypertension, anemia, arteriovenous fistula, and hyperparathyroidism. An important factor to consider in the diagnosis and evaluation of hypertension in this clinical setting is blood pressure (BP) level variation, only accessible using ambulatory BP monitoring (ABPM). In uremic patients, a relative elevation of BP during sleep periods leading to an increased 24-hour BP load is frequently described. Whether this additional BP burden is pathophysiologically significant has not been resolved. This study is designed to examine the effect on echocardiographically derived measurements of the left ventricle in 60 stable chronic hemodialysis patients of abnormal (reduced) diurnal BP variability, measuring ambulatory BP on three occasions and performing echocardiography twice over a 12-month period. First, we found that most dialysis patients (76%) had consistent diurnal BP rhythms over a 12-month period, and second, those patients with persistently reduced diurnal BP rhythm tended to develop a dilated left ventricle and left atrium in the absence of other known and/or relevant risk factors (persistently increased sleep BP group; n = 36; LV end-diastolic diameter, 38.2 +/- 2.5 mm/m(2) versus persistently normal sleep BP group; n = 10; LV end-diastolic diameter, 30.6 +/- 3. 3 mm/m(2); P < 0.05). These results suggest that persistent abnormal BP variability is a risk factor for a dilated heart on dialysis, independent of the BP level.