Discordance of influence of hypertension on mortality and cardiovascular risk in hemodialysis patients

Background: Hemodialysis patients are at significantly increased risk for both morbidity and mortality from cardiovascular disease. However, most recent reports have indicated elevated mortality risk associated with low blood pressure, rather than high blood pressure. We added nonfatal cardiovascular events as an outcome in addition to cardiovascular and all-cause mortality to analyze the risk of hypertension. Methods: One hundred sixty-four patients receiving regular hemodialysis between January and December 1998 were examined and prospectively followed up until the end of 2003. The primary end point was hospital admission or death from cardiovascular disease. Secondary end points were cardiovascular and all-cause mortality. Results: During the 5-year follow-up period, 52 patients experienced cardiovascular events and 45 patients died (18 patients, from cardiovascular disease). Based on Cox analysis, high systolic blood pressure (relative risk [RR], 1.23; 95% confidence interval [CI], 1.07 to 1.43; P = 0.004) and older age were independently associated with cardiovascular events. Elevated systolic blood pressure (RR, 1.25; 95% CI, 0.99 to 1.59; P = 0.063) was a marginal predictor for cardiovascular mortality. Age, serum albumin level, malignant neoplasm, and diabetes were independent risk factors for all-cause mortality, whereas there was no association between blood pressure and all-cause mortality. The hazard ratio for cardiovascular events after adjustment for age, sex, and diabetes was lowest in patients with systolic blood pressure of 140.1 mm Hg or less and progressively increased with the increase in systolic blood pressure. Conclusion: Hypertension is a potent risk factor for cardiovascular disease in hemodialysis patients, as in the general population, whereas there is no association of hypertension with mortality. Active reduction in systolic blood pressure is important to minimize the occurrence of cardiovascular events.