Analysis of the age-shock index and timi score calculated at the bedside in patients with acute st-elevation myocardial infarction admitted to the emergency department

Introduction and Aim: Acute ST-segment elevation myocardial infarction (STEMI) is an event caused by myocardial injury or necrosis secondary to impaired transmural myocardial perfusion. Ischemia develops in the myocardium where oxygen delivery is compromised, leading to a clinical syndrome characterized by electrocardiographic (ECG) changes and chest pain. Despite several limitations, coronary angiography remains the gold standard for diagnosis and treatment of coronary artery disease (CAD). Accurate risk stratification plays a crucial role in the management of patients with acute coronary syndrome (ACS). In STEMI patients, whose access to treatment is known to be easier, risk stratification also affects the prediction of prognosis. Several scoring systems that can be calculated at the bedside have been introduced to determine risk levels in STEMI patients. One of these is the Thrombolysis In Myocardial Infarction (TIMI) risk score, which predicts mortality from all causes within 30 days. The shock index, which is calculated by dividing the heart rate by systolic blood pressure, and the age-shock index, obtained by multiplying the age by the shock index, are thought to be effective in predicting mortality. The aim of this study was to evaluate the predictive power of the age-shock index in predicting mortality and prolonged hospital stays by comparing it with the TIMI score in patients evaluated at the bedside during STEMI. Materials and Methods: Our study was a retrospective, single-center study conducted after obtaining approval from the ethics committee (E-54022451-050.04-137927). Between January 2024 and December 2024, 218 patients diagnosed with STEMI who met the criteria for inclusion were admitted to the emergency department of Bezmiâlem Vakıf University Health Application and Research Center and underwent coronary angiography. Patients who survived were subsequently admitted to the coronary intensive care unit. The aim of our study was to assess the relationship between TIMI risk scores, age-shock index, mortality, and hospital length of stay in our patient group. The study was conducted in compliance with the ethical principles outlined in the Helsinki Declaration. Results: The mean age of the sample was 60.06 ± 12.85 years (Min=30, Max=93). Of the patients, 22.9% (n=50) were female. Regarding the reasons for admission: 89.9% (n=196) presented with typical angina, 5.5% (n=12) with symptoms equivalent to chest pain, and 4.6% (n=10) for other reasons. It was found that 72% (n=157) of the patients had at least one comorbid condition, including coronary artery disease (28.4%), hypertension (39.4%), and diabetes (23.4%). At the time of presentation, 9.6% (n=21) had a respiratory rate of 22 or more, while 90.4% (n=197) had a respiratory rate below 22. The Glasgow Coma Scores (GCS) of the patients were as follows: 97.2% (n=212) had a GCS of 13-15, 1.8% (n=4) had a GCS of 8-12, and 0.9% (n=2) had a GCS below 8. The Mann-Whitney U test revealed that the median age of the surviving patients was statistically significantly lower than that of the deceased patients (p=0.002). The Chi-square test showed that the rates of comorbid diseases (p=0.020) and diabetes (p=0.046) were statistically significantly lower in surviving patients compared to those who died. Significant differences were also found between the two groups regarding gender (p=0.040), symptoms (p=0.004), respiratory rate (p<0.001), and GCS (p<0.001). Additionally, there were statistically significant differences in Killip classification between the two groups (p<0.001). The Mann-Whitney U test found that the median values for systolic blood pressure (p=0.016), diastolic blood pressure (p=0.002), and hospital stay duration in hours (p<0.001) were statistically significantly higher in surviving patients. Heart rate was similar in both groups. The Mann-Whitney U test revealed that the median values for shock index (p=0.002), age-shock index (p=0.002), TIMI-age score (p<0.001), TIMI-Killip score (p<0.001), and TIMI score for STEMI (p<0.001) were statistically significantly lower in surviving patients. Furthermore, the median values for hospital stay (p=0.001) were statistically significantly different between the two groups. ROC Analysis Results: The ROC analysis for shock index and age-shock index showed an AUC of 0.799 (p<0.001), indicating sufficient predictive ability for mortality. Based on this analysis, the optimal cut-off value for the age-shock index was found to be 42.63 (Sensitivity=0.69, Specificity=0.81). For the TIMI score for STEMI, the ROC analysis revealed an AUC of 0.837 (p<0.001), with an optimal cut-off value of 3.5 (Sensitivity=0.85, Specificity=0.63). Conclusion: The results of our study suggest that both the age-shock index and the TIMI score for STEMI can predict mortality and prognosis. Previous studies have compared the predictive power of age-shock index and other scoring systems for mortality in patients presenting with ACS. While the TIMI risk score has high sensitivity but relatively low specificity, the age-shock index demonstrates high specificity and lower sensitivity. Therefore, we believe that the combined use of both parameters would be more successful in accurately predicting mortality risk. Further detailed studies on this topic are needed. Keywords: Acute coronary syndrome, acute myocardial infarction, age-shock index, TIMI risk score, hospital length of stay.