Kusaka Hiroaki, Sugiyama Seigo, Yamamoto Eiichiro, Akiyama Eiichi, Matsuzawa Yasushi, Hirata Yoshihiro, Fujisue Koichiro, Kurokawa Hirofumi, Matsubara Junichi, Sugamura Koichi, Maeda Hirofumi, Jinnouchi Hideaki, Matsui Kunihiko, Ogawa Hisao
Department of Cardiovascular Medicine, Faculty of Life Sciences, Graduate School of Medical Science, Kumamoto University.
Circ J. 2016;80(2):411-7. doi: 10.1253/circj.CJ-15-0878. Epub 2015 Dec 3.
Hyponatremia has been shown to be a prognostic factor in heart failure (HF) with preserved ejection fraction (HFpEF). Serum sodium (sNa) cut-off, however, is not defined in HFpEF. Therefore, we investigated the relationship between sNa and HF-related events (cardiovascular death and hospitalization for HF decompensation) in HFpEF patients.
We assessed cardiac function using echocardiography and measured sNa in HFpEF patients with New York Heart Association class II (n=321) or III (n=84) in a compensated condition after implementing medical therapy for HF. During a mean follow-up of 27 months, 73 patients developed HF-related events. On multivariate Cox hazard analysis including established predictors in HF, sNa level as a continuous variable was identified as an independent predictor for HF-related events in HFpEF (per 1.0 mmol/L: HR, 0.93; 95% CI: 0.87-0.98; P<0.01). Kaplan-Meier analysis demonstrated significantly higher probability of HF-related events in the lower sNa group (sNa <140 mmol/L) than in the higher sNa group (sNa ≥140 mmol/L; P<0.001, log-rank test). Further, the low-normal sNa group (135 mmol/L<sNa<140 mmol/L) was significantly associated with HF-related events compared with the higher sNa group (P<0.001, log-rank test).
sNa as a continuous variable was independently correlated with future HF-related events in HFpEF. Low-normal sNa could provide important prognostic information for practical risk stratification in HFpEF.
低钠血症已被证明是射血分数保留的心力衰竭（HFpEF）的一个预后因素。然而，HFpEF中血清钠（sNa）的临界值尚未明确。因此，我们研究了HFpEF患者中sNa与HF相关事件（心血管死亡和因HF失代偿住院）之间的关系。
我们使用超声心动图评估心脏功能，并在对HF实施药物治疗后，测量处于代偿状态的纽约心脏协会II级（n = 321）或III级（n = 84）的HFpEF患者的sNa。在平均27个月的随访期间，73例患者发生了HF相关事件。在包括HF既定预测因素的多变量Cox风险分析中，sNa水平作为连续变量被确定为HFpEF中HF相关事件的独立预测因素（每1.0 mmol/L：HR，0.93；95%CI：0.87 - 0.98；P<0.01）。Kaplan-Meier分析表明，较低sNa组（sNa <140 mmol/L）发生HF相关事件的概率显著高于较高sNa组（sNa≥140 mmol/L；P<0.001，对数秩检验）。此外，与较高sNa组相比，低正常sNa组（135 mmol/L < sNa < 140 mmol/L）与HF相关事件显著相关（P<0.001，对数秩检验）。
sNa作为连续变量与HFpEF未来的HF相关事件独立相关。低正常sNa可为HFpEF的实际风险分层提供重要的预后信息。
