Systolic Blood Pressure and the Risk of Kidney Replacement Therapy and Mortality in Patients with Chronic Kidney Disease Stages 4-5.

INTRODUCTION: In patients with chronic kidney disease stages 4 and 5 (CKD stages 4-5) without dialysis and arterial hypertension, it is unknown if the values of systolic blood pressure (SBP) considered in control (<120 mm Hg) are associated with kidney replacement therapy (KRT) and mortality. METHODS: In this retrospective cohort study, hypertensive CKD stages 4-5 patients attending the Renal Health Clinic at the Hospital Civil de Guadalajara were enrolled. We divided them into those that achieved SBP <120 mm Hg (controlled group) and those who did not (>120 mm Hg), the uncontrolled group. Our primary objective was to analyze the association between the controlled group and KRT; the secondary objective was the mortality risk and if there were subgroups of patients that achieved more benefit. Data were analyzed using Stata software, version 15.1. RESULTS: During 2017-2022, a total of 275 hypertensive CKD stages 4-5 patients met the inclusion criteria for the analysis: 62 in the controlled group and 213 in the uncontrolled group; mean age 61 years; 49.82% were male; SBP was significantly lower in the controlled group (111 mm Hg) compared to the uncontrolled group (140 mm Hg); eGFR was similar between groups (20.41 mL/min/1.73 m2). There was a tendency to increase the mortality risk in the uncontrolled group (HR 6.47 [0.78-53.27]; p = 0.082) and an association by the Kaplan-Meir analysis (Log-rank p = 0.043). The subgroup analysis for risk of KRT in the controlled group revealed that patients ≥61 years had a lower risk of KRT (HR 0.87 [95% CI, 0-76-0.99]; p = 0.03, p of interaction = 0.005), but no differences were found in the subgroup analysis for mortality. In a follow-up of 1.34 years, no association was found in the risk of KRT according to the controlled or uncontrolled groups in a multivariate Cox analysis. CONCLUSION: In a retrospective cohort of patients with CKD stages 4-5 and hypertension, SBP >120 mm Hg was not associated with risk of KRT but could be associated with the risk of death. Clinical trials are required in this group of patients to demonstrate the impact of reaching the SBP goals recommended by the KDIGO guidelines.

Serum Potassium Trajectory during Acute Kidney Injury and Mortality Risk.

BACKGROUND: The association between potassium (sK) level trajectory and mortality or the need for kidney replacement therapy (KRT) during acute kidney injury (AKI) has not been adequately explored. METHODS: In this prospective cohort, AKI patients admitted to the Hospital Civil de Guadalajara were enrolled. Eight groups based on the sK (mEq/L) level trajectories during 10 days of hospitalization were created (1) normokalemia (normoK), defined as sK between 3.5-5.5; (2) hyperkalemia to normoK; (3) hypokalemia to normoK; (4) fluctuating potassium; (5) persistent hypoK; (6) normoK to hypoK; (7) normoK to hyperK; (8) persistent hyperK. We assessed the association of sK trajectories with mortality and the need for KRT. RESULTS: A total of 311 AKI patients were included. The mean age was 52.6 years, and 58.6% were male. AKI stage 3 was present in 63.9%. KRT started in 36% patients, and 21.2% died. After adjusting for confounders, 10-day hospital mortality was significantly higher in groups 7 and 8 (OR, 1.35 and 1.61, p < 0.05, for both, respectively), and KRT initiation was higher only in group 8 (OR 1.38, p < 0.05) compared with group 1. Mortality in different subgroups of patients in group 8 did not change the primary results. CONCLUSION: In our prospective cohort, most patients with AKI had alterations in sK+. NormoK to hyperK and persistent hyperK were associated with death, while only persistent hyperK was correlated with the need for KRT.

How to interpret serum creatinine increases during decongestion.

During decongestion in acute decompensated heart failure (ADHF), it is common to observe elevations in serum creatinine (sCr) values due to vascular congestion, a mechanism that involves increased central venous pressure that has a negative impact on the nephron, promoting greater absorption of water and sodium, increased interstitial pressure in an encapsulated organ developing "renal tamponade" which is one of main physiopathological mechanism associated with impaired kidney function. For the treatment of this syndrome, it is recommended to use diuretics that generate a high urinary output and natriuresis to decongest the venous system, during this process the sCr values can rise, a phenomenon that may bother some cardiologist and nephrologist, since raise the suspicion of kidney damage that could worsen the prognosis of these patients. It is recommended that increases of up to 0.5 mg/dL from baseline are acceptable, but some patients have higher increases, and we believe that an arbitrary number would be impractical for everyone. These increases in sCr may be related to changes in glomerular hemodynamics and true hypovolemia associated with decongestion, but it is unlikely that they are due to structural injury or truly hypoperfusion and may even have a positive connotation if accompanied by an effective decongestion and be associated with a better prognosis in the medium to long term with fewer major cardiovascular and renal events. In this review, we give a comprehensive point of view on the interpretation of creatinine elevation during decongestion in patients with ADHF.