住院扩张型心肌病患者低钠血症的发生率及其对预后的判断价值

Prevalence of Hyponatremia and the Relationship Between Hyponatremia and Prognosis of Dilated Cardiomyopathy for In-hospital Patients

目的：调查住院扩张型心肌病（DCM）患者低钠血症的发生率及其对预后的判断价值。方法：连续入选2008-10至2013-10于阜外心血管病医院心衰监护病房住院的DCM患者。以患者首次入院时血清钠浓度〈135 mmol/L定义为低钠血症，调查住院DCM患者低钠血症的发生率，评价其与预后的关系，包括住院时间和院内死亡风险，以及出院后全因死亡率和心衰加重死亡率。存活出院患者由门诊或电话随访至2014-11或全因死亡。结果：共有515例DCM患者纳入本研究，其中134例患者入院时存在低钠血症，发生率为26.0%。入院血钠浓度与入院时心衰病史、纽约心脏协会（NYHA）心功能分级Ⅱ～Ⅳ级、收缩压水平、左心房前后径及总胆红素水平显著相关（P均〈0.05）。与非低钠血症患者相比，低钠血症患者平均住院时间长[（14.8±11.1）d vs （11.2±5.8）d，P 〈0.01]，院内死亡风险高（18.7% vs 1.8%，P 〈0.01）。483例存活出院患者平均随访（30.7±19.5）月后全因死亡率为26.5%，心衰加重死亡率为21.9%。低钠血症患者全因死亡率（47.7% vs 20.3%，P 〈0.01）及心衰加重死亡率（44.0% vs 15.5%，P 〈0.01）均显著高于非低钠血症患者。多变量Cox回归分析结果显示，校正入院时心衰病史（〉6个月vs ≤6个月）、NYHA心功能分级Ⅱ~Ⅳ级、收缩压水平（每升高10 mmHg，1 mmHg=0.133 kPa）、总胆红素水平（每变化1 mg/dl）及左心室舒张末期内径（每变化5 mm）后，入院低钠血症仍是存活出院DCM患者全因死亡[危险比（HR）=1.836，95%（可信区间）CI：1.248~2.702，P 〈0.01]及心衰加重死亡（HR =2.139，95% CI：1.406~3.253，P 〈0.01）的重要独立预测因素之一。结论：低钠血症是我国住院DCM患者常见的电解质紊乱类型之一，与患者住院时间长、院内死亡风险高，以及出院后全因死亡及心衰加重死亡显著相关。

Objective： To investigate the prevalence of hyponatremia and the relationship between hyponatremia and prognosis of dilated cardiomyopathy （DCM） for in-hospital patients. Methods： A total of 515 consecutive in-hospital DCM patients treated in HF center of Fu Wai Hospifal from 2008-10 to 2013-10 were retrospectively studied. Hyponatremia was deifned as the serum level of sodium 〈 135 mmol/L at ifrst admission. The prevalence of hyponatremia and the relationship between hyponatremia and DCM prognosis were studied including the risk of in-hospital time and mortality, the rates of all cause death and HF worsening death after discharge. Surviving patients were followed-up by clinical or telephone visit until 2014-11 or until the death. Results： There were 134/515 （26.0%） patients suffered from hyponatremia at admission, the serum level of sodium was related to HF symptom duration, NYHA functional classiifcation, systolic blood pressure （SBP）, left atrial diameter and total bilirubin level, allP〈0.01. Compared with non-hyponatremia, the patients with hyponatremia presented longer in-hospital time（14.8±11.1） days vs （11.2±5.8） days and higher in-hospital mortality （18.7% vs 1.8%）, bothP〈 0.01. There were 483 survivors discharged and were followed-up for （30.7 ± 19.5） months, during that period, the rates of all cause death and HF worsening death were 26.5% and 21.9% respectively. The patients with hyponatremia had the higher rates of all cause death （47.7% vs 20.3%） and HF worsening death （44.0% vs 15.5%）, bothP〈0.01. Multiple Cox regression analysis showed that with adjusted HF history （〉 6 months vs≤ months ）, NYHA functional classiifcation （Ⅱ-Ⅳ）, SBP （per 10 mmHg elevation）, total bilirubin level （per 1 mg/dl change） and LVEDD （per 5 mm change）, the hyponatremia at admission is still one of the important independent predictors for all cause death （HR=1.836, 95% CI （1.248-2.702）,P〈0.01 and HF worsening death HR=2.139, 95% CI （1.406-3.253）,P〈0.01 in DCM patients after discharge. Conclusion： Hyponatremia is a common electrolyte disorder for in-hospital DCM patients, it is related to longer in-hospital time and higher mortality; higher rates of all cause death and HF worsening death after discharge in DCM patients.