Blood pressure targets for hemodialysis patients: Aspirational or practical?

Whereas there is strong relationship between high blood pressure and increased overall and cardiovascular mortality for the general population, observational studies in hemodialysis patients have reported a "U" shaped relationship between pre-hemodialysis blood pressure recordings and patient survival. Previous attempts to introduce pre and post-hemodialysis blood pressure targets were associated with an increased frequency of intra-dialytic hypotension, itself an independent risk factor for mortality. Conversely, meta-analyses of trials of antihypertensive medications in hemodialysis patients, reported survival benefit for those prescribed medication. More recently, further meta-analyses have suggested a reduced risk for cardiovascular mortality benefit with a systolic blood pressures (SBPs) of less than 140 mmHg, the absolute benefit, in terms of risk reduction was greatest in those with the highest vascular disease burden. Even though data from current observational studies and studies of antihypertensive medications would suggest that patient survival would be greater with pre-dialysis SBP should be less than 160 mmHg, there is no current data to propose specific blood pressure targets. Defining blood pressure targets can only be answered by adequately powered prospective randomized controlled trials comparing different targets. As the benefits of lowering blood pressure appear to be greatest for those with most vascular disease, then blood pressure targets may have to be adjusted on an individual risk basis, and future trials should therefore stratify patients according to vascular morbidity and have different targets for patients with differing degrees of pre-existing cardiovascular disease.