Laboratory and instrumental parameters associated with the risk of death in the long-term follow-up period in patients after myocardial infarction

Abstract

BACKGROUND: In patients who successfully survived the 1st year after myocardial infarction, the risk of death remains elevated. AIM: To determine laboratory and instrumental parameters of myocardial remodeling associated with a lethal outcome in the long-term follow-up period in patients 1 year after myocardial infarction. MATERIAL AND METHODS: The study included 184 patients 12 months after myocardial infarction: the first group — living patients at the 5-year follow-up point (n=160), the second group — deceased patients at the 5-year follow-up point (n=24). A comparative analysis of inflammation and myocardial dysfunction biomarkers, as well as echocardiographic parameters reflecting the types of left ventricular remodeling, linear dimensions of the cavities and wall thickness of the heart, chamber volumes, and ventricular systolic function was retrospectively performed. After assessing the distribution of quantitative data, the Student's t-test or Mann–Whitney U-test and the χ2 criterion for categorical data were used. The model was built on the basis of logistic regression. The ROC curve, the Hosmer–Lemeshow test, and the bootstrap method were used to assess the model itself and its reliability. RESULTS: Patients in the second group were older (p=0.007), and more often had myocardial infarction with ST-segment elevation during hospitalization (p 0.001). Twelve months after myocardial infarction, a multidirectional pattern of changes in the level of N-terminal brain natriuretic propeptide was revealed: a decrease was registered in the first group, while an increase was registered in the second group. In the dynamics of the second group, the index of end-diastolic volume (p=0.014) and the size of left ventricular asynergy were higher (p=0.043), and the ejection fraction was lower (p=0.015) than in the first group. The model for predicting 4-year mortality in patients who survived myocardial infarction during the 1st year included such parameters as the index of the left ventricular end-diastolic volume, the content of the N-terminal fragment of the natriuretic peptide and the presence of concentric hypertrophy of the left ventricle. CONCLUSION: In patients who survived 1 year after myocardial infarction, the long-term risk of death is associated with a set of parameters reflecting left ventricular remodeling and the development of heart failure.