Acute Declines in Renal Function during Intensive BP Lowering and Long-Term Risk of Death

Abstract

Background: During intensive BP lowering, acute declines in renal function are common, thought to be hemodynamic, and potentially reversible. We previously showed that acute declines in renal function ≥20% during intensive BP lowering were associated with higher risk of ESRD. Here, we determined whether acute declines in renal function during intensive BP lowering were associated with mortality risk among 1660 participants of the African American Study of Kidney Disease and Hypertension and the Modification of Diet in Renal Disease Trial.

Methods: We used Cox models to examine the association between percentage decline in eGFR (<5%, 5% to <20%, or ≥20%) between randomization and months 3-4 of the trials (period of therapy intensification) and death.

Results: In adjusted analyses, compared with a <5% eGFR decline in the usual BP arm (reference), a 5% to <20% eGFR decline in the intensive BP arm was associated with a survival benefit (hazard ratio [HR], 0.77; 95% confidence interval [95% CI], 0.62 to 0.96), but a 5% to <20% eGFR decline in the usual BP arm was not (HR, 1.01; 95% CI, 0.81 to 1.26; P<0.05 for the interaction between intensive and usual BP arms for mortality risk). A ≥20% eGFR decline was not associated with risk of death in the intensive BP arm (HR, 1.18; 95% CI, 0.86 to 1.62), but it was associated with a higher risk of death in the usual BP arm (HR, 1.40; 95% CI, 1.04 to 1.89) compared with the reference group.

Conclusions: Intensive BP lowering was associated with a mortality benefit only if declines in eGFR were <20%.

Keywords: AASK (African American Study of Kidney Disease and Hypertension); chronic renal disease; hypertension; mortality risk.

Figure 1.

Acute declines in renal function of <15% in the intensive BP arm is associated with lower mortality risk compared to the reference group (<5% decline in the usual BP arm). Association between 5% increments in renal function decline and risk of death in adjusted Cox models using a <5% decline in renal function in the usual BP arm as the reference group. All hazard ratios are adjusted for age, sex, race, baseline heart disease, baseline angiotensin-converting enzyme inhibitor use, baseline eGFR category, baseline proteinuria category, baseline mean arterial pressure, and stratified by trial data source. 95% CI, 95% confidence interval.