Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts.
Am J Cardiol. 2013 Dec 1;112(11):1763-9. doi: 10.1016/j.amjcard.2013.07.020. Epub 2013 Oct 4.
Serum magnesium levels may be impacted by neurohormonal activation, renal function, and diuretics. The clinical profile and prognostic significance of serum magnesium level concentration in patients hospitalized for heart failure (HF) with reduced ejection fraction is unclear. In this retrospective analysis of the placebo group of the Efficacy of Vasopressin Antagonism in Heart Failure Outcome Study with Tolvaptan trial, we evaluated 1,982 patients hospitalized for worsening HF with ejection fractions ≤40%. Baseline magnesium levels were measured within 48 hours of admission and analyzed as a continuous variable and in quartiles. The primary end points of all-cause mortality (ACM) and cardiovascular mortality or HF rehospitalization were analyzed using Cox regression models. Mean baseline magnesium level was 2.1 ± 0.3 mg/dl. Compared with the lowest quartile, patients in the highest magnesium level quartile were more likely to be older, men, have lower heart rates and blood pressures, have ischemic HF origin, and have higher creatinine and natriuretic peptide levels (all p <0.003). During a median follow-up of 9.9 months, every 1-mg/dl increase in magnesium level was associated with higher ACM (hazard ratio [HR] 1.77; 95% confidence interval [CI] 1.35 to 2.32; p <0.001) and the composite end point (HR 1.44; 95% CI 1.15 to 1.81; p = 0.002). However, after adjustment for known baseline covariates, serum magnesium level was no longer an independent predictor of either ACM (HR 0.94, 95% CI 0.69 to 1.28; p = 0.7) or the composite end point (HR 1.01, 95% CI 0.79 to 1.30; p = 0.9). In conclusion, despite theoretical concerns, baseline magnesium level was not independently associated with worse outcomes in this cohort. Further research is needed to understand the importance of serum magnesium levels in specific HF patient populations.
血清镁水平可能受到神经激素激活、肾功能和利尿剂的影响。在射血分数降低的心力衰竭（HF）住院患者中，血清镁浓度的临床特征和预后意义尚不清楚。在托伐普坦治疗心力衰竭结局试验的血管加压素拮抗剂疗效研究安慰剂组的回顾性分析中，我们评估了 1982 名因射血分数≤40%的 HF 恶化而住院的患者。入院后 48 小时内测量基线镁水平，并作为连续变量和四分位数进行分析。使用 Cox 回归模型分析全因死亡率（ACM）和心血管死亡率或 HF 再入院的主要终点。与最低四分位数相比，镁水平最高四分位数的患者年龄更大、男性更多、心率和血压更低、HF 起源为缺血性、肌酐和利钠肽水平更高（所有 p <0.003）。在中位随访 9.9 个月期间，镁水平每增加 1mg/dl，ACM 增加（危险比 [HR] 1.77；95%置信区间 [CI] 1.35 至 2.32；p <0.001）和复合终点（HR 1.44；95% CI 1.15 至 1.81；p=0.002）的风险更高。然而，在校正已知的基线协变量后，血清镁水平不再是 ACM（HR 0.94，95% CI 0.69 至 1.28；p=0.7）或复合终点（HR 1.01，95% CI 0.79 至 1.30；p=0.9）的独立预测因子。总之，尽管存在理论上的担忧，但在本队列中，基线镁水平与结局恶化无关。需要进一步研究以了解血清镁水平在特定 HF 患者人群中的重要性。
