Intensive BP control can delay kidney replacement therapy in Stage 4/5 CKD

Recent research found that intensive blood pressure control has a beneficial effect of delaying kidney replacement therapy in stage 4 and 5 chronic kidney disease patients. The study results were published in the Journal of the American Society of Nephrology. 

Hypertension and chronic kidney disease (CKD) are closely interlinked pathophysiologic states where sustained hypertension can worsen renal function leading to a progressive decline in kidney function thus worsening blood pressure (BP) control. It is quite necessary to have intensive blood pressure control where a systolic BP of <120 mmHg is maintained. As there is uncertainty about the effect of intensive BP lowering on the risk of kidney failure requiring kidney replacement therapy (KRT) in patients with advanced CKD, researchers conducted a pooled analysis to examine the effect of intensive BP lowering on KRT risk. 

A pooled analysis of individual-level data from seven trials was carried out by including patients with eGFR<60 mL/min per 1.73 m2. A prespecified subgroup analysis was carried out to evaluate the effect of intensive BP control by baseline albuminuria and eGFR (CKD stage 4–5 versus stage 3). 

Key findings of the study: 

• Among the 5823 trial participants, 526 developed the kidney outcome and 382 died.
• Even though there was no statistical significance, intensive (versus usual) BP control was associated with a lower risk of kidney outcome and death in unadjusted analyses. 
• Based on the baseline eGFR, the intervention’s effect on the kidney outcome varied (P interaction=0.05).
• By intention-to-treat analysis, intensive (versus usual) BP control was associated with a 20% lower risk of the primary kidney outcome in those with CKD GFR stage 4–5, but not in CKD GFR stage 3.
• There was no interaction between intensive BP control and the severity of albuminuria for kidney outcomes. 

Thus, the pooled analysis suggested no evidence of harm but an advantage of intensive BP control in delaying kidney replacement therapy in patients with stages 4–5 CKD but not stage 3 CKD. 

Further reading: Ku, Elaine, McCulloch, Charles E, Inker, Lesley A, et al. Intensive BP Control in Patients with CKD and Risk for Adverse Outcomes. Journal of the American Society of Nephrology. January 17, 2023. | DOI: 10.1681/ASN.0000000000000072