Prognostic importance of hyponatremia in acute ST-elevation myocardial infarction

• Published in: The American journal of medicine Vol. 117; no. 4; pp. 242 - 248
• Main Authors: Goldberg, Alexander, Hammerman, Haim, Petcherski, Sirouch, Zdorovyak, Alexander, Yalonetsky, Sergey, Kapeliovich, Michael, Agmon, Yoram, Markiewicz, Walter, Aronson, Doron
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 15.08.2004; Elsevier
• Subjects: Aged; Biological and medical sciences; Biomarkers - blood; Blood Glucose - metabolism; Blood Pressure - physiology; Cardiology. Vascular system; Coronary heart disease; Creatine Kinase - blood; Female; General aspects; Heart; Heart Conduction System - metabolism; Heart Conduction System - pathology; Heart Rate - physiology; Humans; Hyponatremia - blood; Hyponatremia - diagnosis; Hyponatremia - mortality; Israel - epidemiology; Male; Medical sciences; Middle Aged; Multivariate Analysis; Myocardial Infarction - blood; Myocardial Infarction - diagnosis; Myocardial Infarction - mortality; Myocarditis. Cardiomyopathies; Predictive Value of Tests; Prevalence; Prognosis; Risk Assessment; Sodium - blood; Statistics as Topic; Stroke Volume - physiology; Survival Analysis; Israel; Myocardial infarction; Hydroelectrolytic balance disorder; Hyponatremia; Prognosis; Acute; Cardiovascular disease; Myocardial disease; Inorganic element; Medicine; ST elevation; Metabolic disorder; Sodium; Heart disease
• ISSN: 0002-9343; 1555-7162
• DOI: 10.1016/j.amjmed.2004.03.022

To determine the prevalence and prognostic implications of hyponatremia in the setting of acute ST-elevation myocardial infarction. The study sample consisted of 1047 consecutive patients presenting with acute ST-elevation myocardial infarction. Plasma sodium concentrations were obtained on admission and at 24, 48, and 72 hours thereafter. Infarct size was determined by echocardiographic examination that was performed on day 2 or 3 of hospitalization. Hyponatremia, defined as a plasma sodium level <135 mmol/L (<135 mEq/L), was present on admission in 131 patients (12.5%) and developed during the first 72 hours of hospitalization in 208 patients (19.9%). Plasma sodium levels decreased to ≤130 mmol/L in 45 patients (4.3%). In a multivariate logistic regression analysis, hyponatremia was independently associated with 30-day mortality. The risk of 30-day mortality associated with hyponatremia on admission (odds ratio [OR] = 2.0; 95% confidence interval [CI]: 1.0 to 3.9; P = 0.04) was similar to that of hyponatremia developing after admission (OR = 2.4; 95% CI: 1.5 to 4.2; P = 0.002). The risk of 30-day mortality increased with the severity of hyponatremia, with an odds ratio of 2.1 in patients with sodium levels between 130 and 134 mmol/L (95% CI: 1.2 to 3.5; P = 0.007) and 3.4 in those with levels <130 mmol/L (95% CI: 1.5 to 7.8; P = 0.002). Hyponatremia on admission or early development of hyponatremia in patients with acute ST-elevation myocardial infarction is an independent predictor of 30-day mortality, and prognosis worsens with the severity of hyponatremia. Further studies are required to determine if plasma sodium levels may serve as a simple marker to identify patients at high risk.