Intensive BP lowering may reduce mortality in CKD
Intensive blood pressure (BP) lowering appears to reduce mortality risk during treatment in individuals with hypertension and moderate-to-advanced chronic kidney disease (CKD), findings from a recent systematic review and meta-analysis show.
Patients with CKD who underwent more intensive BP lowering (lower BP targets) had a reduced risk of all-cause mortality during active treatment compared with those who underwent less intensive BP lowering (higher BP targets; odds ratio, 0.86, 95 percent confidence interval, 0.76–0.97; p=0.01). [JAMA Intern Med 2017;doi:10.1001/jamainternmed.2017.4377]
Mean systolic BP reduced by 16 mm Hg reaching 132 mm Hg in patients treated with more intensive BP lowering and reduced by 8 mm Hg reaching 140 mm Hg in patients treated with less intensive BP lowering.
The impact of more intensive BP lowering on mortality appeared consistent regardless of comparator treatment type, median follow-up duration, inclusion or exclusion of patients with diabetes, severity of CKD, overall cohort baseline systolic BP, or systolic BP achieved by patients assigned to more intensive BP lowering.
The findings were based on a systematic review and meta-analysis of 18 randomized controlled trials that included patients aged ≥18 years (n=15,924) with hypertension (mean baseline systolic blood pressure, 148 mm Hg) and CKD stages 3–5 (estimated glomerular filtration rate [eGFR], <60 mL/min/1.73m2). Of these, 13 trials compared two specific BP targets, while the other five compared active BP lowering with placebo or no treatment. Studies involving patients undergoing dialysis were excluded. A total of 1,293 deaths occurred during the active treatment phase of the trials (n=584 and 709 in the more and less intensive BP lowering arms, respectively) and patients were followed up over a median 3.6 years.
“These findings add to the body of evidence that may inform public health policy, clinical guideline development, and individual patient care in patients with CKD,” said the researchers.
“Our results may also offer additional information for patients and healthcare professionals and may be useful to guide shared decision making about the relative risks and benefits of BP lowering among those with CKD,” they said.
The impact of more intensive BP lowering on mortality could not be stratified by CKD severity, said the researchers. Furthermore, a majority of patients had stage 3 CKD and thus, the results may not be applicable to patients with more advanced disease.
“[T]hese data support that the net benefits may outweigh the net harms of more intensive BP lowering in persons with CKD,” they said, though further research, particularly with regards to safety, is required to establish these findings.
However, Professor Csaba Kovesdy from the University of Tennessee Health Science Center, Memphis, Tennessee, US, has some reservations about the outcomes of this trial.
“One could … interpret the results of this meta-analysis as solidifying existing evidence about the benefits of lowering BP to a range of 130 to 140 mm Hg but not as proof that truly intensive BP lowering [ie, to a target <120 mm Hg] is beneficial,” he said in a commentary. [JAMA Intern Med 2017;doi:10.1001/jamainternmed.2017.4467]
“A further concern is that lumping all patients with an eGFR below 60 mL/min/1.73m2 together under the umbrella of CKD risks mixing different populations that may very well have divergent responses to BP lowering,” he said, highlighting that the benefits of reducing systolic BP even further, particularly in patients with advanced CKD, needs to be elucidated.