Shah Vraj, Jahan Nusrat
Cardiology, California Institute of Behavioral Neurosciences and Psychology, Fairfield, USA.
Internal Medicine, California Institute of Behavioral Neurosciences and Psychology, Fairfield, USA.
Cureus. 2019 Sep 16;11(9):e5673. doi: 10.7759/cureus.5673.
ST-elevation myocardial infarction (STEMI) and heart failure (HF) are common, big-budget, debilitating and expanding diseases. Cardiovascular diseases, especially STEMI and heart failure have been known to cause 17.3 million deaths worldwide annually. Hyponatremia, delineated as a serum sodium (sNa) concentration <135 mmol/l, is a frequently seen electrolyte disturbance in practice and the prevalence, clinical impact; the prognostic factor of low SNa in STEMI/heart failure patients vary widely. The aim of this review is to assess its existence and comparing survival difference between hypo and normonatremic patients. A comprehensive review of the published articles was conducted using database PubMed. We found a total of over 1400 articles. The inclusion criteria used for this review were age >65 years, published within the last 10 years, written in English, performed on human subjects and of studies such as reviews and randomized controlled trials (RCTs), especially for heart failure MeSH words. By applying this inclusion criterion, we found out 40 relevant articles which included 26 cohort studies, four clinical trials, four review articles, and six RCTs. In the analysis of 7,06,899 patients with STEMI/heart failure, hyponatremia was significantly linked to causing all-cause mortality, both short and long term (hazard ratio [HR] as continuous variable: 1.06; 95% confidence interval [CI]: 1.01-1.11; P = 0.026; HR as categorical variable: 1.71; 95% CI: 1.06-2.75; P = 0.028). The rates of rehospitalization were also higher (odds ratio, 1.68; 95% confidence interval, 1.32-2.14) along with prolonged hospital stays as well as a greater cost burden as compared to patients with normal serum sodium. It was existent not only in patients with reduced ejection fraction (HFrEF) but also in subjects with preserved ejection fraction (HFpEF) (HR 1.40, 95% CI 1.12 to 1.75, P = 0.004). Rise of first follow-up and discharge sodium does seem to have positive linkage on survival as well (hazard ratio [HR] 0.429, 95% CI 0.191-0.960, P = 0.04). Hyponatremia is the most frequently encountered electrolyte abnormality in clinical practice and has a poor prognosis in both STEMI and heart failure patients. It exacerbates both short and long term mortality, rehospitalization rates, as well as the average length of stay in the hospital. Although it is still a mystery whether hyponatremia is just a marker of iller patients or the core of poor prognosis in patients with STEMI and HF, one thing is certain: timely recognition of patients at risk for developing hyponatremia could help to commence early treatment.
ST段抬高型心肌梗死（STEMI）和心力衰竭（HF）是常见的、花费巨大、使人衰弱且呈增长态势的疾病。已知心血管疾病，尤其是STEMI和心力衰竭，每年在全球导致1730万人死亡。低钠血症定义为血清钠（sNa）浓度<135 mmol/l，是临床上常见的电解质紊乱，其在STEMI/心力衰竭患者中的患病率、临床影响以及低sNa的预后因素差异很大。本综述的目的是评估其存在情况，并比较低钠血症患者和血钠正常患者的生存差异。我们使用PubMed数据库对已发表的文章进行了全面检索。共找到1400多篇文章。本综述采用的纳入标准为年龄>65岁、过去10年内发表、英文撰写、针对人类受试者以及诸如综述和随机对照试验（RCT）等研究类型，特别是针对心力衰竭的医学主题词。通过应用该纳入标准，我们找出了40篇相关文章，其中包括26项队列研究、4项临床试验、4篇综述文章和6项RCT。在对706899例STEMI/心力衰竭患者的分析中，低钠血症与全因死亡率显著相关，无论是短期还是长期（作为连续变量的风险比[HR]：1.06；95%置信区间[CI]：1.01 - 1.11；P = 0.026；作为分类变量的HR：1.71；95% CI：1.06 - 2.75；P = 0.028）。与血钠正常的患者相比，再住院率也更高（优势比，1.68；95%置信区间，1.32 - 2.14），同时住院时间延长且费用负担更大。低钠血症不仅存在于射血分数降低（HFrEF）的患者中，也存在于射血分数保留（HFpEF）的患者中（HR 1.40，95% CI 1.12至1.75，P = 0.004）。首次随访和出院时血钠的升高似乎对生存也有正向关联（风险比[HR] 0.429，95% CI 0.191 - 0.960，P = 0.04）。低钠血症是临床实践中最常遇到的电解质异常，在STEMI和心力衰竭患者中预后均较差。它会加剧短期和长期死亡率、再住院率以及平均住院时间。尽管低钠血症究竟只是病情较重患者的一个指标，还是STEMI和HF患者预后不良的核心因素仍是一个谜，但有一点是肯定的：及时识别有发生低钠血症风险的患者有助于尽早开始治疗。
