Relevance. The sulfation of homocysteine is an important element in protecting cells against ischemic-reperfusion injury. In clinical studies the positive effect of N-acetylcysteine ​​on the reduction of necrosis was found in patients with STEMI. Objective of this study was to evaluate the baseline levels of sulphur-containing amino acids in plasma as predictors of early (on the day of admission) systolic dysfunction of left ventricle (SDLV) and acute heart failure (HF) in patients with STEMI without reperfusion therapy (RT). Material and methods. 92 patients with STEMI without RT were examined. The content of free plasma sulphur-containing aminо acids (homocysteine, cysteine ​​and methionine) was investigated on the day of admission by ion-exchanged liquid-column chromatography. Results. The complications of STEMI were associated with increased baseline levels of sulphur-containing aminо acids, especially, cysteine ​​and methionine. Its levels were significantly higher (at 71.7%, р<0.01, and 41.3%, р<0.05, respectively) in patients with early SDLV compared with patients with ejection fraction of left ventricle (LVEF) >40%. The multivariate logistic regression analysis revealed that the baseline level of cysteine in patients with STEMI remained an independent predictor of early (on the day of admission) SDLV (OR=17.4, p<0.001) after adjustment for anamnestic and laboratory factors. The sensitivity and specificity of baseline cysteine ​​level >0.49 mg/dl as a marker of early SDLV were 73.9% and 65.2% respectively (AUC=0.72, p=0.006). The multivariate analysis revealed that the baseline level of methionine was an independent predictor of acute HF on the day of admission after adjustment for laboratory factors (OR=25.9, p<0.001). Also methionine was an independent predictor of persistent / late HF on third day or later in total sampling (OR=25.9, p<0.001) after adjustment for demographic, anamnestic and clinic factors (OR=68.7, p<0.0001), as well as after adjustment for laboratory risk factors (OR=42.5, p<0.0001). The sensitivity and specificity of baseline methionine ​​level >0.31 mg/dl as a marker of persistent / late HF were 87.5% and 63.3% respectively (AUC = 0.77, p <0.0001). Also the baseline level of methionine was an independent predictor of persistent / late HF in patients with EFLV >40% after adjustment for demographic and anamnestic factors (OR=113.3, p <0,0001). The sensitivity and specificity of methionine ​​level >0.41 mg/dl as a marker of persistent / late HF in patients with EFLV >40% were 80.0% and 81.0% respectively (AUC=0.80, р<0.0001). Conclusions. The complicated course of STEMI without RT is associated with increased level of sulphur-containing aminо acids, especially, cysteine ​​and methionine. A higher level of cysteine ​​is associated with early SDLV independently from anamnesis risk factors and creatinine level in plasma. The risk of persistent / late HF (on third day and later) is associated with a higher level of methionine independently from demographic, anamnestic, clinical and laboratory factors risk.

Nowadays, the problem of preventing acute heart failure (AHF) in patients with ST-elevation myocardial infarction (STEMI) and preserved left-ventricular ejection fraction (pLVEF) is still not completely resolved, especially in late-presented patients. The purpose of study was: (1) assessment of free plasma amino acid (PAA) alterations in STEMI patients [not receiving reperfusion therapy (RT)], depending on sex and LVEF; (2) analysis of development of late/persistent AHF more than 48 h after admission (pAHF) in STEMI patients with pLVEF depending on PAA levels. This prospective cohort study included 92 STEMI patients (33 women and 59 men), not receiving RT. The free PAA were investigated by ion-exchange liquid-column chromatography. The women had significantly higher PAA levels than men in general cohort and cohort with pLVEF (n = 69). There were associations between female sex and pAHF in general cohort (OR 3.7, p = 0.004) and cohort with pLVEF (OR 11.4, p = 0.0001) by logistic regression. The association between pAHF and glycine level [OR 2.5, p < 0.0001; AUC 0.84, p < 0.0001; 86.7% sensitivity and 77.8% specificity for > 2.6 mg/dL] was revealed in cohort with pLVEF (including female and male). Glycine remained a predictor of pAHF with pLVEF by multivariable logistic regression adjusting for comorbidities, demographic and clinical variables. Higher rate of pAHF in female than in male STEMI patients with pLVEF is associated with higher plasma glycine in women. The glycine level may be genetically determinated by female sex. The plasma glycine > 2.6 mg/dL is a predictor of pAHF in STEMI with pLVEF (including female and male).