Magnesium is an essential mineral for the human body and plays an important role in cardiovascular health. Hypomagnesaemia has been linked with increased cardiovascular mortality in heart failure; however, previous studies have yielded conflicting results. Even fewer studies have addressed the association between hypermagnesemia and prognosis in heart failure. The aim of the present systematic review was to investigate the association of serum magnesium levels with cardiovascular and all-cause mortality in patients with heart failure and reduced ejection fraction (HFrEF). Cardiovascular morbidity, referring to heart failure rehospitalizations and ventricular arrhythmias, was also investigated. Eligible studies were identified by searching PubMed and Scopus. The Quality in Prognosis (QUIPS) tool was used to assess the quality of included studies. Eight studies (total of 13,539 patients with HFrEF) that assessed the effects of serum magnesium levels on cardiovascular mortality, all-cause mortality, and cardiovascular morbidity met inclusion criteria. In half of the studies, hypomagnesemia was found to be an independent risk factor for cardiovascular mortality, including sudden cardiac death. Only 1 study reported that hypermagnesemia (serum magnesium levels above 2.4 mg/dL) is a prognostic factor for noncardiac mortality suggesting that hypermagnesemia is more likely an indicator of comorbidities rather than a true independent prognostic marker. Finally, low serum magnesium levels were not associated with readmissions for heart failure or ventricular arrhythmias in patients with HFrEF.

镁是人体必需的矿物质，对心血管健康起着重要作用。低镁血症与心力衰竭的心血管死亡率增加有关。然而，之前的研究得出了相互矛盾的结果。探讨高镁血症与心力衰竭预后之间关系的研究就更少了。本系统评价的目的是调查心力衰竭和射血分数降低（HFrEF）患者的血清镁水平与心血管死亡率和全因死亡率的关系。还对心血管发病率（指心力衰竭再住院和室性心律失常）进行了调查。通过搜索 PubMed 和 Scopus 来确定合格的研究。预后质量（QUIPS）工具用于评估纳入研究的质量。评估血清镁水平对心血管死亡率、全因死亡率和心血管发病率影响的八项研究（总共 13,539 名 HFrEF 患者）符合纳入标准。在一半的研究中，发现低镁血症是心血管死亡（包括心源性猝死）的独立危险因素。只有 1 项研究报告称高镁血症（血清镁水平高于 2.4 mg/dL）是非心源性死亡的预后因素，表明高镁血症更有可能是合并症的指标，而不是真正的独立预后标志物。最后，低血清镁水平与 HFrEF 患者因心力衰竭或室性心律失常再次入院无关。