[The impact of age and gender on the cut-off value of acute myocardial infarction in patients with first-time high-sensitivity troponin T elevation and the evaluation of diagnostic efficacy].

To explore the influence of gender and age on the cutoff values of initial high-sensitivity cardiac troponin T (hs-cTnT) elevation in patients and identify optimal diagnostic cutoff values that better meet clinical needs, providing an objective basis for early diagnosis and intervention of acute myocardial infarction (AMI). This cross-sectional retrospective study included 622 patients with suspected AMI who were initially diagnosed and entered the Chest Pain Center treatment pathway emergency departments of Jinan Fourth People's Hospital from December 2022 to August 2023. Patients were categorized by gender, age, and clinical diagnosis. Receiver Operating Characteristic (ROC) curves and Youden indices were used to determine the optimal diagnostic cutoff points for hs-cTnT, evaluating the impact of gender and age on cut-off values and screening cutoff values with the best diagnostic performance under the clinical emergency requirement of positive predictive value (PPV)>85%. The results showed that no significant differences were observed between the AMI group (n=172) and non-AMI group (n=450) in gender, conduction block, atrial fibrillation, hypertension, diabetes, or chronic heart failure (all P>0.05). However, significant differences were found in age [73 (65, 81) years vs. 69 (60, 79) years, Z=-2.55, P=0.011], smoking status [77 (17.11%) vs. 42 (24.42%), χ²=4.93, P=0.038], and ST-T segment changes [224 (49.78%) vs. 108 (62.79%), χ²=8.48, P=0.040]. In the AMI group, age and gender had no significant effect on hs-cTnT concentrations (P>0.05). Binary logistic regression indicated that age was an independent factor associated with AMI diagnosis in this high-risk cohort [OR<1, Exp(b)=0.983]. ROC analysis under PPV>85% identified the following cut-off values: overall (51.60 ng/L), younger group (50.51 ng/L), older group (54.33 ng/L), female group (54.22 ng/L), and male group (49.32 ng/L). At the overall cut-off value of 51.60 ng/L, sensitivity was 0.59, specificity 0.96, PPV 85.0%, and NPV 86.1%, showing higher diagnostic efficacy than other cut-offs. In conclusion,among high-risk patients with initial hs-cTnT elevation, gender-and age-specific diagnostic cut-off values differ under the requirement of PPV>85%, with age having a greater influence on cut-off values. Adopting population-specific cut-off values reduces false-positive cases, conserves medical resources, and optimizes clinical workflows.