Prediction of adverse outcomes within 12 months after myocardial infarction in patients over 70 years of age with frailty syndrome

Abstract

Aim. To develop a predictive model of the risk of adverse outcomes within 12 months after myocardial infarction (MI) in patients over 70 years of age with frailty syndrome.Material and methods. This prospective observational study included 92 patients over 70 years of age with MI who were treated in the cardiology departments of Samara State Medical University Clinics from 2020 to 2021. Levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) and growth stimulation expressed gene 2 (ST2) were determined in serum by enzyme-linked immunosorbent assay on day 5 of hospitalization. Frailty syndrome was identified 5th day of hospitalization using "Age is not a hindrance" questionnaire. The observation period was 12 months. The end point was the adverse event occurrence (all-cause death, cardiovascular death, recurrent MI, cerebrovascular accident). Statistical nonparametric methods, correlation analysis, ROC analysis, and logistic regression were used.Results. There are following significant predictors of unfavorable outcome within 12 months after MI in patients over 70 years: age over 80 years (odds ratio (OR) 5,57, 95% confidence interval (CI) 2,07-14,96, with p=0,001), history of MI (OR 3,96, 95% CI 1,36-10,26, at p<0,05), CKD-EPI glomerular filtration rate <55 ml min/1,73 m2 (OR 4,05, 95% CI 1,55-10,57, with p=0,004), pulmonary artery systolic pressure above 38 mm Hg (OR 4,5, 95% CI 1,69-11,96, with p=0,003), Simpson's left ventricular ejection fraction <45% (OR 12,21, 95% CI 4,2-35,57, with p<0,001), as well as "Age is not a hindrance" questionnaire score ≥3 (OR 9,62, 95% CI 2,96-31,25, with p<0,001), Charlson Comorbidity Index score ≥6 (OR 10,4, 95% CI 2,84-38,12, with p<0,001), NT-proBNP ≥1400 pg/ml (OR 7,09, 95% CI 2,53-19,89, with p<0,001) and ST2 ≥8,2 ng/ml (OR 9,13, 95% CI 2,79-29,89, p<0,001). Percutaneous coronary intervention during the current hospitalization reduced the risk of adverse outcomes (OR 0,24, 95% CI 0,09-0,69, p=0,015). Predictive model for unfavorable outcome within 12 months after MI for patients over 70 years of age based on the "Age is not a hindrance" questionnaire score, serum ST2 level in ng/ml and left ventricular ejection fraction in % in ROC analysis has an area under the curve of 0,87 (95% CI 0,79-0,95), sensitivity — 86%, specificity — 71% (p<0,001).Conclusion. Prediction of an unfavorable outcome based on the "Age is not a hindrance" questionnaire score, Simpson's left ventricular ejection fraction in %, and ST2 concentration can improve risk stratification for adverse outcomes within 12 months after MI in patients over 70 years.