Omar Hesham R, Charnigo Richard, Guglin Maya
Internal Medicine Department, Mercy Medical Center, Clinton, Iowa.
Department of Biostatistics, University of Kentucky, Lexington, Kentucky.
Am J Cardiol. 2017 Aug 15;120(4):607-615. doi: 10.1016/j.amjcard.2017.05.030. Epub 2017 May 30.
Hyponatremia in acute decompensated heart failure (HF) is indicative of a poor prognosis and predicts morbidity and mortality. We explored the predictive utility of hyponatremia at the time of hospital discharge among HF patients with normal admission sodium (Na). Characteristics and outcomes of HF patients enrolled in the Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness trial, who had normal Na on admission, were compared between those who were hyponatremic (Na <135 meq/L) or normonatremic on discharge. Three hundred six patients with normal admission Na had either hyponatremia (n = 86) or normal Na (n = 220) on discharge. Compared with patients with normal Na on discharge, hyponatremic patients were younger (p = 0.004), with lower discharge systolic (p <0.001) and diastolic (p = 0.004) blood pressure, higher discharge blood urea nitrogen (p = 0.011) despite similar creatinine (p = 0.566), lower ejection fraction (p = 0.007), and higher left ventricular end-diastolic (p = 0.028) and end-systolic (p = 0.007) dimensions. Despite comparable congestion on hospital admission, patients with discharge hyponatremia had a higher degree of decongestion throughout hospitalization evident in the significantly greater admission to discharge weight loss (p = 0.044) and admission to discharge reduction in inferior vena cava diameter (p = 0.014). Despite longer initial hospitalization (p = 0.004), total duration in hospital at 30 days (p = 0.004) and 6 months (p = 0.045), there were no significant differences between patients with discharge hyponatremia versus normal Na on discharge regarding rehospitalization (p = 0.386), all-cause mortality (p = 0.440), and composite of death, cardiac rehospitalization, and cardiac transplant (p = 0.799), all up to 6-month following randomization. Restricted cubic spline analysis also showed no significant relationships between discharge Na and the aforementioned 3 outcomes. Cox proportional hazards regressions showed that discharge hyponatremia did not significantly predict any of the 3 outcomes after adjustment for imbalances at baseline. Among patients with discharge hyponatremia, a poor outcome was more likely if they were also hyponatremic on admission: the composite end point occurred in 69.2% of those also hyponatremic on admission versus 51.2% of those with normal Na on admission but decreased Na on discharge (p = 0.045). Because the median discharge Na level in the discharge hyponatremia group was 132 meq/L, our findings suggest a benign nature of mild discharge hyponatremia in HF patients with normal admission Na.
急性失代偿性心力衰竭（HF）中的低钠血症提示预后不良，并可预测发病率和死亡率。我们探讨了入院时血钠正常的HF患者出院时低钠血症的预测效用。比较了充血性心力衰竭和肺动脉导管插入术有效性评估研究试验中入院时血钠正常的HF患者的特征和结局，这些患者出院时为低钠血症（血钠<135 meq/L）或血钠正常。306例入院时血钠正常的患者出院时出现低钠血症（n = 86）或血钠正常（n = 220）。与出院时血钠正常的患者相比，低钠血症患者更年轻（p = 0.004），出院时收缩压（p <0.001）和舒张压（p = 0.004）更低，尽管肌酐水平相似（p = 0.566），但出院时血尿素氮更高（p = 0.011），射血分数更低（p = 0.007），左心室舒张末期（p = 0.028）和收缩末期（p = 0.007）内径更大。尽管入院时充血情况相当，但出院时低钠血症的患者在整个住院期间的消肿程度更高，这在入院到出院的体重减轻（p = 0.044）和入院到出院的下腔静脉直径减小（p = 0.014）中明显可见。尽管初始住院时间更长（p = 0.004），30天（p = 0.004）和6个月（p = 0.045）的总住院时间更长，但出院时低钠血症患者与出院时血钠正常的患者在再住院（p = 0.386）、全因死亡率（p = 0.440）以及死亡、心脏再住院和心脏移植的复合结局（p = 0.799）方面均无显著差异，所有这些均在随机分组后的6个月内。受限立方样条分析也显示出院时血钠与上述3种结局之间无显著关系。Cox比例风险回归显示，在对基线不平衡进行调整后，出院时低钠血症并未显著预测这3种结局中的任何一种。在出院时低钠血症的患者中，如果入院时也为低钠血症，则更有可能出现不良结局：复合终点在入院时也为低钠血症的患者中发生率为69.2%，而入院时血钠正常但出院时血钠降低的患者中发生率为51.2%（p = 0.045）。由于出院时低钠血症组的血钠中位数水平为132 meq/L，我们的研究结果表明，入院时血钠正常的HF患者中轻度出院时低钠血症具有良性性质。
