Treatment of hypertension in renal failure patients: when do we overtreat? When do we undertreat?

Abstract

Despite the commonplace nature of hypertension in chronic dialysis patients, many issues remain unresolved. According to current JNC/V (see text) recommendation, a systolic blood pressure of < 120 mm Hg is optimal, 120-129 mm Hg is normal, and one of 130-139 mm Hg is high-normal. The majority of dialysis patients receiving treatment in the United States is probably not maintained in the optimal blood pressure range. However, if the J curve hypothesis has credence, many of our dialysis patients may be susceptible to overtreatment, especially of their diastolic blood pressure. In patients with ischemic cardiovascular disease, several studies show a decrease in survival with diastolic blood pressures < 85 mm Hg. This J curve phenomenon is seen predominantly in patients with ischemic heart disease. Since many, and possibly most, of the currently treated end-stage renal disease patients in the United States have existing atherosclerotic cardiovascular disease when they start chronic dialysis therapy, lowering of the diastolic blood pressure below a J threshold may be dangerous. This problem may be especially prevalent in diabetics with diabetic cardiomyopathy. Diabetics and other end-stage renal disease patients may be started on hemodialysis with glomerular filtration rates in the 10- to 15-cm2/min range. Patients with high residual renal function may have small intradialytic weight gains and frequent intradialytic hypotension. This 'overtreatment' may lead to postdialysis arrhythmias and sudden death in chronic dialysis patients. As in the nonrenal failure population, end-stage renal disease patients with left ventricular hypertrophy have a 2- to 3-fold increased risk of death from cardiovascular diseases, and all cause mortality. In contrast to nonrenal failure patients, normotensive ESRD patients may show an increase of left ventricular mass over time. Although left ventricular hypertrophy can be reversed with good blood pressure control, patients are often undertreated based on analysis of dialysis clinic blood pressures. Even if clinic systolic blood pressure levels are optimal, chronic dialysis patients may still have unacceptably high ambulatory blood pressure levels due to a rise in nocturnal blood pressure with sleep.