BackgroundMagnesium is an essential micronutrient for people and is crucial in maintaining healthy cardiac function. It functions as a cofactor in a number of the body's enzyme systems, and myocardial cells are one of its target tissues. The upkeep of the myocardium's normal functional integrity depends on a lot of things including magnesium ions.Magnesium plays an important role in the pathophysiology of cardiovascular disorders.AimThis study aims to estimate serum magnesium levels and their correlation with cardiac complications and mortality in patients with acute myocardial infarction (AMI).MethodsPatients with acute myocardial infarction who visited the Prince Faisal Bin Khalid Cardiac Center within 12 hours of the onset of symptoms were the subjects of this study. On the first and fifth days following admission, the level of serum magnesium was assessed. Statistical Package for Social Sciences (SPSS) version 20 (IBM SPSS Statistics, Armonk, NY) was used to analyze the collected data.ResultsThe current study comprised 160 patients with acute myocardial infarction; there were 84 (52.5%) who experienced a low level of serum magnesium on admission. Significantly higher proportions of patients who experienced low magnesium levels had diabetes mellitus (P=0.0072) and a history of diuretics (P=0.03) and were administrated beta-blockers (P=0.01), calcium channel blockers (P=0.04), and statins (P=0.007) after admission. Significantly higher proportions of patients with low serum magnesium experienced atrial fibrillation (P=0.03), angina (P=0.03), and cardiogenic shock (P=0.003).ConclusionLow magnesium levels are associated with poor outcomes in most patients admitted with acute myocardial infarction.