Low intracellular magnesium levels promote platelet-dependent thrombosis in patients with coronary artery disease

Background Although reduced intracellular levels of magnesium have been des cribed in patients with acute myocardial infarction, its significance as a regulator of thrombosis remains unknown. Methods and Results To determine whether reduced intracellular levels of ma gnesium enhance platelet-dependent thrombosis, we evaluated 42 patients wit h coronary artery disease (CAD) by exposing porcine aortic media to their F lowing unanticoagulated venous blood for 5 minutes by using an ex vivo perf usion (Badimon) chamber. Baseline analysis demonstrated significant associa tions between intracellular levels of magnesium, platelet-dependent thrombo sis (P =.02), and platelet P-selectin (CD62P) expression (P <.05), Patients were divided into 2 groups: below (n = 22) and above (n = 20) the median i ntracellular levels of magnesium (1.12, mu g/mg protein). There were no sig nificant differences in age, body mass index, serum lipids, fibrinogen, pla telet count, or serum magnesium levels between the two groups. Platelet-dep endent thrombosis was significantly higher in patients with intracellular l evels of magnesium below compared with above median (150+/- 128 vs 45 +/- 2 8 mu m(2)/mm, P <.004). Neither platelet aggregation nor CD62P expression w as significantly different between the two groups. Conclusions Platelet-dependent thrombosis was significantly increased in pa tients with stable CAD with low intracellular levels of magnesium, suggesti ng a potential role for magnesium supplementation in CAD.