Strict BP Control Linked to Higher Mortality in CKD

In patients with CKD, strict BP control—leading to a treated systolic BP (SBP) below 120 mm Hg—is associated with increased all-cause mortality, reports a study in JAMA Internal Medicine.

The historical cohort study drew from a nationwide cohort of veterans with CKD in the United States. Of the total 651,479 patients with CKD, 77,765 had uncontrolled hypertension leading to treatment with at least one additional BP medication, with evidence of subsequent reduction in SBP. In a model including propensity scores, the researchers compared all-cause mortality for patients receiving strict BP control (treated SBP <120 mm Hg) with those receiving conventional BP control (treated SBP <140 mm Hg).

Treated SBP was less than 120 mm Hg in 5760 patients and 120 to 139 mm Hg in 72,005 patients. During a median follow-up time of 6.0 years, the rate of death was 80.9 per 1000 patient-years for patients with strict BP control compared with 41.8 per 1000 patient-years for those with conventional BP control.

With adjustment for propensity scores, the hazard ratio for death for patients with a treated SBP below 120 mm Hg was 1.70. The findings were consistent in subgroup analyses and in a subcohort analysis using the inclusion and exclusion criteria of the ongoing Systolic Blood Pressure Interventional Trial (SPRINT).

There are concerns about the safety of strict BP control strategies in certain groups of patients, including those with CKD. The new analysis adds to the evidence that strict control may not be beneficial, and may actually be harmful, in CKD patients. The researchers write: “Such an observational approach to estimate treatment targets for blood pressure lowering in patients with CKD could be a useful complement to clinical trials” [Kovesdy CP, et al. Observational modeling of strict vs conventional blood pressure control in patients with chronic kidney disease. JAMA Intern Med August 04, 2014. doi: 10.1001/jamainternmed.2014.3279].