住院心力衰竭患者入院时低钠血症的发生率及其对预后的影响

Prevalence and prognostic value of hyponatremia on admission in hospitalized patients with heart failure

目的 调查来自我国首个心力衰竭（心衰）管理中心的住院心衰患者入院时低钠血症的发生率及其对预后的影响.方法 连续入选2009年3月至2012年3月于阜外心血管病医院心衰监护病房住院的成人（首次入院年龄≥18岁）症状性心衰[纽约心脏病协会（NYHA）心功能分级Ⅱ～Ⅳ级]患者,以血清钠浓度＜ 135 mmol/L定义为低钠血症,调查我国心衰住院患者入院时低钠血症的发生率,分析入院低钠血症与心衰住院患者院内死亡及出院随访1年内全因死亡和心衰死亡的关系.结果 共有1 048例基线资料完整的心衰住院患者纳入研究,其中入院低钠血症的患者96例,研究对象入院低钠血症的发生率为9.2％ （96/1 048）.与非低钠血症患者相比,低钠血症患者入院血压水平较低、NYHA心功能分级及N末端B型利钠肽原（NT-proBNP）水平较高（P均＜0.01）.Kaplan-Meier生存分析结果显示,低钠血症患者院内死亡率、随访1年内全因死亡及心衰死亡风险均明显高于非低钠血症患者（P均＜0.01）.多变量Cox比例风险模型分析结果显示,校正多种混杂因素后,入院时低钠血症仍然是心衰住院患者随访1年内全因死亡（HR=2.105,95％ CI1.460 ～ 3.036,P＜0.01）和心衰死亡（HR=2.458,95％ CI1.704～3.545,P＜0.01）的独立预测因素.结论 低钠血症是住院心衰患者常见的电解质紊乱类型之一,入院低钠血症是我国住院心衰患者院内死亡及随访1年内全因死亡和心衰死亡的独立预测因素.

Objective To investigate the prevalence and prognostic value of hyponatremia on admission in hospitalized patients for heart failure （HF） from the first HF management center in China.Methods Consecutive adult （age of 18 years or older） symptomatic HF patients （NYHA functional class Ⅱ-Ⅳ） admitted between March 2009 and March 2012 in our center were included in the present analysis.Hyponatremia was defined as a serum sodium level 〈 135 mmol/L.Association between hyponatremia on admission and in-hospital mortality as well as all-cause death and heart failure death during 1-year follow-up after discharge was analyzed.Results A total of 1 048 hospitalized patients for HF with complete baseline data were enrolled and the prevalence of hyponatremia on admission was 9.2% （96/1 048）.Blood pressure was significantly lower while NYHA functional class and N-terminal pro-B type natriuretic peptide levels were significantly higher in hyponatremic patients than non-hyponatremic patients （all P 〈 0.05）.Kaplan-Meier survival analysis showed that patients with hyponatremia on admission had significant higher in-hospital mortality （P 〈 0.01）, all-cause death rate （P 〈 0.01） and HF death rate （P 〈 0.01） during 1-year follow-up post discharge compared with non-hyponatremic patients with.Multiple Cox proportional hazard analysis showed that hyponatremia on admission remained as independent predictor for all-cause death （hazard risk （HR） =2.105, 95% confidence interval （CI） 1.460-3.036, P 〈 0.01） and HF death （HR =2.458, 95%CI： 1.704-3.545, P 〈0.01） after adjustment for other covariates.Conclusion Hyponatremia is relatively common in patients hospitalized with HF in China and hyponatremia on admission is associated with higher in-hospital mortality and all-cause death and HF death one year after discharge.