Effect of intensive blood pressure control on long-term kidney outcomes

In the Systolic Blood Pressure Intervention Trial (SPRINT), intensive blood pressure (BP) lowering reduced the risk of cardiovascular disease and all-cause mortality, compared with standard BP control. However, among those without CKD at baseline, intensive BP lowering was associated with a higher risk of an acute decrease in kidney function and of acute kidney injury.

To understand the long-term effects of intensive BP lowering on kidney outcomes, investigators used SPRINT data and electronic health record (EHR) creatinine values to follow participants after the conclusion of the original trial.

SPRINT enrolled adults aged ≥50 years with a systolic BP of 130–180 mmHg and at least one additional indicator of cardiovascular risk. They were randomised to intensive treatment, with a target of SBP <120 mmHg, or standard treatment, with a target of <140 mmHg. Serum creatinine levels were assessed at baseline and during follow-up visits.

EHR creatinine values were available for 3041 participants for a median of 8.3 years after randomisation, providing >5 years of post-intervention follow-up. During the intervention phase, the total slope of decline in eGFR was significantly faster in the intensive treatment group (–0.96 mL/min/1.73 m² per year [95% CI, –1.08 to –0.85]) compared to the standard treatment group (–0.67 mL/min/1.73 m² per year [–0.79 to –0.56]).

During the post-intervention observation phase, there was no significant difference in the slopes, with a decline of –0.85 mL/min/1.73 m² per year (–1.07 to –0.64) in the intensive group compared to –1.02 mL/min/1.73 m² per year (–1.24 to –0.81) in the standard group.

Furthermore, among those without CKD at baseline, during the intervention phase only, there was a significantly higher risk of a ≥30% decline in eGFR in the intensive group compared to the standard group (HR, 3.27 [2.43 to 4.40]). Also only during the intervention phase, those with CKD experienced a higher risk of a ≥50% decline in eGFR or kidney failure with intensive treatment (HR, 1.95 [1.03 to 3.70]).

The authors conclude that there was no long-term effect of intensive antihypertensive therapy on eGFR slope or secondary outcomes during the post-intervention observational phase.

The full article can be read here.