We present a statistical interpretation of plasma (Pl) and (or) erythrocyte (Erc) concentrations of magnesium, zinc, calcium, potassium, and total high-density lipoprotein (HDL) cholesterol, as well as of the activity of total creatine kinase (CK) and its CK-MB isoenzyme, in 26 men with pre-infarction syndrome (PIS) and 34 men with acute myocardial infarction (MI). Discriminant analysis allowed overall comparison of both groups and determination of the most significant variables: CK and Pl-Zn. By non-hierarchical cluster analysis we defined three homogeneous subgroups among MI men, with CK, CK-MB, and Pl-Zn differing significantly between the groups. In PIS men, Pl-Zn was correlated with Pl-Ca, whereas in MI men Pl-Zn was correlated with Pl-Mg. Stepwise regression indicated that Pl-Zn was the most significant regressor of CK in PIS men and of CK-MB in MI men. All these statistical interpretations support a special role of Pl-Zn in diagnosis and perhaps prognosis. After MI, interleukin-1 release may possibly mediate observed hypozincemia via formation of a heart Zn-metallothionein.