Objective: This study aimed to investigate the impact of the duration of cardiac troponin I (TnI) elevation on the prognosis and incidence of new-onset atrial fibrillation (NOAF) in elderly patients with non-ST-elevation acute myocardial infarction (NSTE-AMI).
Methods: A total of 383 NSTE-AMI patients ≥ 75 years old were enrolled in this study and divided into two groups: in 194 cases, the duration of TnI elevation was ≥ 14 days (group 1), and in 189 cases, the duration of TnI elevation was < 14 days (group 2). The patients were followed up for 60 months. The effect of TnI on prognosis was studied by cohort. The primary endpoint was a composite endpoint of cardiovascular death, reinfarction, ischemic stroke, and hospitalization for heart failure, and the secondary endpoint was all-cause death. A case–control study design was adopted to analyze the influencing factors of NOAF occurrence in Group 1 and Group 2.
Results: The median duration of follow-up was 26 months. Multivariate Cox’s regression analysis revealed that the duration of TnI elevation ≥ 14 days and diuretic use were independent variables of the major composite endpoint (p < 0.01 for both), and the left ventricular ejection fraction and the duration of TnI elevation ≥ 14 days were independent related variables of all-cause death (p < 0.05). The duration of TnI elevation ≥ 14 days was correlated with the occurrence of NOAF, but, in the multivariate logistic regression model, only uric acid and high-sensitivity C-reactive protein were independently associated with NOAF (p < 0.05).
Conclusion: The duration of TnI elevation ≥ 14 days was the independent correlation factor of the major composite endpoint and all-cause death; high sensitivity C-reactive protein and uric acid are independent risk factors for NOAF.
Keywords: duration of TnI elevation, the elderly, non-ST-segment acute elevation acute myocardial infarction, prognosis, new-onset atrial fibrillation