Risk Estimation in Type 2 Myocardial Infarction and Myocardial Injury: The TARRACO Risk Score

BACKGROUND: Despite adverse prognoses of type 2 myocardial infarction and myocardial injury, an effective, practical risk stratification method remains an unmet clinical need. We sought to develop an efficient clinical bedside tool for estimating the risk of major adverse cardiovascular events at 180 days for this patient population. METHODS: The derivation cohort included patients with type 2 myocardial infarction or myocardial injury admitted to a tertiary hospital between 2012 and 2013 (n = 611). The primary outcome was a major adverse cardiovascular event (death or readmission for heart failure or myocardial infarction). The score included clinical variables significantly associated with the outcome. External validation was conducted using the UTROPIA cohort (n = 401). RESULTS: The TARRACO Score included cardiac troponin (cTn) concentrations and 5 independent clinical predictors of adverse cardiovascular events: age, hypertension, absence of chest pain, dyspnea, and anemia. The score exhibited good discriminative accuracy (area under the curve = 0.74; 95% CI, 0.70-0.79). Patients were classified into low-risk (score 0-6) and high-risk (score ≥7) categories. Major adverse cardiovascular events rates were 5 times more likely in high-risk patients compared with those at low risk (78.9 vs 15.4 events/100 patient-years, respectively; logrank P <.001). The external validation showed equivalent prognostic capacity (area under the curve=0.71, 0.65-0.78). CONCLUSION: A novel risk score based on bedside clinical variables and cTn concentrations allows risk stratification for death and cardiac-related rehospitalizations in patients with type 2 myocardial infarctions and myocardial injury. This score identifies patients at the highest risk of adverse events, a subset of patients who may benefit from close observation, medical intensification, or both.