Serial sodium values and adverse outcomes in heart failure with preserved ejection fraction

• Published in: International journal of cardiology Vol. 290; pp. 119 - 124
• Main Authors: Imran, Tasnim F., Kurgansky, Katherine E., Patel, Yash R., Orkaby, Ariela R., McLean, Robert R., Ho, Yuk-Lam, Cho, Kelly, Gaziano, J. Michael, Djousse, Luc, Gagnon, David R., Joseph, Jacob
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.09.2019
• Subjects: Aged; Aged, 80 and over; Biomarkers - blood; Cohort Studies; Female; Follow-Up Studies; Heart Failure - blood; Heart Failure - diagnosis; Heart Failure - mortality; Heart failure hospitalization; Heart failure with preserved ejection fraction; Hospitalization; Humans; Male; Middle Aged; Mortality; Mortality - trends; Outcomes; Serum sodium; Sodium - blood; Stroke Volume - physiology; Treatment Outcome; Heart failure with preserved ejection fraction; Hospitalization; Heart failure hospitalization; Mortality; Outcomes; Serum sodium
• ISSN: 0167-5273; 1874-1754
• DOI: 10.1016/j.ijcard.2019.03.040

The purpose of our study is to examine whether serial measurements of serum sodium values after diagnosis identify a higher-risk subset of patients with heart failure with preserved ejection fraction. We identified 50,932 subjects with HFpEF with 759,577 recorded sNa measurements (mean age 72 ± 11 years) using a validated algorithm in the VA national database from 2002 to 2012. We examined the association of repeated measures of sNa with mortality using a multivariable Cox proportional hazards model. After a median follow-up of 2.9 years (IQR: 1.2–5.4), 19,011 deaths occurred. After adjusting for age, sex, race, BMI, glomerular filtration rate, potassium, coronary artery disease, hypertension, hyperlipidemia, atrial fibrillation, pulmonary disease, diabetes, anemia, and medications, we found J-shaped associations of serum sodium with mortality. HRs for all-cause mortality were 2.48 (95% CI: 2.38–2.60) for the sNA 115.00–133.99 category; and 1.40 (95% CI: 1.35–1.46) for the sNA 143.00–175.00 category compared to the 137.01–140.99 category (ref). We used generalized estimating equation-based negative binomial regression to compute the incidence density ratios (IDR) to examine days hospitalized for heart failure and for all causes. There were a total of 1,275,614 days of all-cause hospitalization and 104,006 days of heart-failure hospitalization. The IDRs for the lowest sNA group were 2.03 (95% CI: 1.90–2.18) for all-cause hospitalization and 1.73 (95% CI: 1.39–2.16) for heart-failure hospitalization. Our findings suggest that monitoring of serum sodium values during longitudinal follow-up can identify HFpEF patients at risk of adverse outcomes. •A J-shaped association exists between serial serum sodium measurements and major adverse outcomes in HFpEF.•Low serum sodium measurement recorded at any time after HFpEF diagnosis is associated with a higher risk of adverse outcomes.•This association could be secondary to neurohormonal activation in HFpEF.