Effects of Hyponatremia Correction on Mortality and Rehospitalization

Hyponatremia is associated with higher mortality and rehospitalization, but it was unknown whether this is a causal relationship, making the problem difficult to correct. Therefore, Julie Refardt and colleagues evaluated the direct effects on mortality and rehospitalization rates of targeted hyponatremia correction versus routine care. They presented results at ASN Kidney Week 2024 in the oral session, Impact of Targeted Hyponatremia Correction on 30-Day Mortality and Rehospitalization Rate.

The researchers conducted a randomized, controlled, superiority, parallel-group, international, multicenter trial with blinded outcome assessment. The study included 2,174 patients hospitalized with hyponatremia <130 mmol/L from nine tertiary centers throughout Europe. Of the full cohort, 1,079 (49.6%) patients were randomized to undergo targeted correction of plasma sodium levels according to guidelines (intervention group), while 1,095 (50.4%) were assigned routine care for hyponatremia (control group). The primary outcome was the combined risk of death or rehospitalization within 30 days of inclusion in the study.

Of the intervention group, 641 (60.4%) patients achieved normonatremia compared to 493 (46.2%) patients in the control group. Within 30 days, death occurred in 93 (8.6%) patients in the intervention group, compared to 93 (8.5%) patients in the control group. Rehospitalization occurred among 138 (13.0%) patients in the intervention group and among 151 (14.0%) patients in the control group. This resulted in a combined event rate of 21.0% (224/1,079 patients) in the intervention group and 22.2% (239/1,095 patients) in the control group (estimated absolute difference in proportions 95% CI, -1.2% [-4.7, 2.3]; P=.50).

The results remained strong in the per protocol analysis and in subgroup analyses accounting for hyponatremia etiology, severity, or correction rate. In conclusion, targeted plasma sodium correction did not reduce 30-day mortality or rehospitalization rates. “This suggests that in hospitalized patients, chronic hyponatremia is a marker of disease severity rather than a cause of worse outcome,” the researchers concluded.

Source: Refardt J, Potasso L, Pelouto A, et al. Impact of targeted hyponatremia correction on 30-day mortality and rehospitalization rate. SA-OR91. Abstract of an oral presentation at the American Society of Nephrology Kidney Week 2024; October 26, 2024; San Diego, California.