Application of thrombolysis in myocardial infarction risk index in the prediction of long-term outcomes for patients with ST-elevation myocardial infarction and multiple vessel disease: A single-center prospective observational cohort study

The thrombolysis in myocardial infarction (TIMI) risk index has been indicated to be a simple and useful tool for risk stratification of patients with ST-elevation myocardial infarction (STEMI). However, the predictive value of the TIMI risk index regarding the long-term outcome for patients with STEMI with multiple vessel disease has remained to be determined. In the present study, a total of 369 patients diagnosed with STEMI who received emergency percutaneous coronary intervention treatment were analyzed. A five-year follow-up was performed to record the primary endpoint of all-cause mortality, as well as the secondary endpoints of myocardial infarction, stroke, emergent revascularization and admission due to heart failure. A receiver operating characteristic (ROC) curve was used to determine the cut-off value of the TIMI risk index for predicting all-cause death, based on which the patients were divided into a high TIMI group and a low TIMI group. Kaplan-Meier survival curves were used to compare the long-term survival of the two groups and multivariate Cox regression analysis was used to evaluate the predictive value of the risk factors regarding primary and secondary endpoints. The ROC curve indicated that the TIMI risk index was associated with three-year all-cause death with a cut-off value of 30.35 (area under curve, 0.705; P=0.001). The high TIMI group (>30.35) and low TIMI group (<30.35) exhibited a significant difference in all-cause death (P=0.009) but not in any of the secondary endpoints (P=0.527). Multivariate Cox regression analysis demonstrated that a high TIMI risk index was an independent risk factor for all-cause death in patients with STEMI and multiple-vessel disease (hazard ratio=3.709, 95% CI: 1.521-9.046, P=0.004). In conclusion, the TIMI risk index was associated with long-term outcomes for patients with STEMI and multiple-vessel disease and may be of value for risk prediction.