Intensive blood pressure (BP) control in hypertensive patients with chronic kidney disease is associated with a lower risk of end-stage renal disease (ESRD) and death in certain subgroups of patients, according to a new study.
Achieving lower BP targets appears to be particularly beneficial in decreasing ESRD risk among patients who are older, are obese, or have greater proteinuria, a team led by Elaine Ku, MD, of the University of California, San Francisco, reported in the Journal of the American Heart Association. Intensive BP lowering also is especially beneficial in decreasing mortality risk among patients with advanced kidney disease.
The study pooled data from 2 completed trials of intensive BP lowering: the Modification of Diet in Renal Disease (MDRD) and African American Study of Kidney Disease and Hypertension (AASK) trials. Dr Ku and her colleagues included 840 MDRD and 1067 AASK participants. Patients had a mean age of 53 years and median glomerular filtration rate (GFR) of 40 mL/min/1.73 m2. The median follow-up duration from randomization until death or administrative censoring was 14.9 years. ESRD developed in 498 and 526 patients in the intensive control and usual control arms, respectively. A total of 438 and 482 deaths occurred in the intensive control and usual control arms, respectively.
Compared with usual control, intensive control was associated with a significant 18% decreased risk of ESRD among patients aged 40 years or older, a significant 23% decreased risk of ESRD among patients with proteinuria of 0.44 g/g or higher, and a significant 25% decreased risk of ESRD among patients with a body mass index (BMI) of 30 kg/m2 or higher. Intensive BP control was not protective against ESRD risk among patients younger than 40 years, those with proteinuria below 0.44 g/g, and those with a BMI less than 30 kg/m2. In addition, intensive control was associated with a significant 27% decreased risk of death among patients with a GFR below 30 mL/min/1.73 m2, but was not protective against death among those with higher GFRs.
“We believe our study is unique in its provision of long-term follow-up that extends the mean duration of most clinical trials (2–3 years),” the authors stated.
Strengths of the new study include the large number of ESRD events and deaths and the availability of nearly 2 decades of follow-up in MDRD and AASK trial participants, Dr Ku’s team noted. With regard to study limitations, the authors pointed out that their results may not apply to patients with CKD attributed to diabetes mellitus, and they did not have detailed data on cardiovascular events such as stroke or new-onset heart failure that may have developed with each of the treatment strategies during long-term follow-up.
Ku E, Sarnak MJ, Toto R, et al. Effect of blood pressure control on long-term risk of end-stage renal disease and death among subgrups of patients with chronic kidney disease. J Am Heart Assoc. 2019;8:e012749. doi: 10.1161/JAHA.119.012749.