Abstract 8991: Prognostic Significance of Hyponatremia in Peripartum Cardiomyopathy: Insights from the Peripartum Cardiomyopathy in Nigeria Registry

Abstract

Introduction: Hyponatraemia is a well-described independent poor prognostic marker for heart failure (HF). However, its prognostic significance in peripartum cardiomyopathy (PPCM) is unknown. Hypothesis: We hypothesized that hyponatremia will have prognostic significance in PPCM patients. Methods: In this post-hoc analysis of PEACE registry results, we aimed to determine the prognostic significance of hyponatremia in PPCM patients. We consecutively recruited the PPCM patients from 14 sites in Nigeria and followed them up for a median of 18 months. Serum sodium was measured at baseline, and patients with hyponatremia (<135mmol/L) were compared with those with normal values. Unrecovered LV systolic function was defined as LVEF ≤55%. Predictors of mortality were determined using a Cox-Proportional Hazard Regression model. Results: Overall, 90 of 191 (47.1%) PPCM patients had hyponatremia at presentation, with a mean serum sodium concentration of 126.7±22.3mmol/L (Table 1). Baseline clinical characteristics and prescriptions for diuretics and other HF drugs were well-balanced between the 2 groups. All-cause mortality among hyponatremic patients (24/90; 26.7%) was significantly higher than among patients with normal serum sodium (7/101; 6.9%) (p-value<0.001). The risk for all-cause mortality was independently increased by hyponatremia (Hazard Ratio: 3.18 [95% CI: 1.35-7.52; p=0.008]), hypotension (systolic BP<100mmHg) (2.22 [1.03-4.79]; p=0.043) and LVEF <25% (3.14[1.47-6.73], p=0.003), after adjusting for loop diuretics, serum creatinine, preeclampsia and tachycardia. Majority of the patients did not recover LV systolic function and rehospitalization was uncommon in both groups. Conclusions: Hyponatremia was common in our cohort of PPCM patients, and associated with 3-fold higher risk for all-cause mortality. It was however not associated with rehospitalization and unrecovered LV systolic function.