Risk of complications after a non-ST segment elevation acute myocardial infarction in a Latin-American cohort: An application of the ACTION ICU score

Background: European Society of Cardiology (ESC) guidelines for the management of acute coronary syndromes in patients presenting without persistent ST-segment elevation (NSTEMI) recommend Intensive Care Unit (ICU) surveillance during the first 24-48 h. Interestingly, the in-hospital mortality of NSTEMI patients has consistently decreased, giving some patients the option to be managed in general hospital wards. The ACTION ICU score has been proposed to identify high-risk patients with NSTEMI and guide the selective risk-based need for ICU care.

Objective: To evaluate the usefulness of the ACTION ICU score to predict patients' risk of developing complications requiring ICU care in a Latin-American cohort with NSTEMI.

Methods: We applied the ACTION ICU score in a retrospective cohort. A composite primary outcome included: cardiorespiratory arrest, shock, high-grade atrio-ventricular block, respiratory failure, stroke, or death. The predictive performance of this model was estimated with a conditional multivariable logistic regression analysis.

Results: Of 1,062 patients with NSTEMI, the primary outcome was present in 75 patients (7.1%), and 1,019 (96%) were admitted to ICU. The most common event was respiratory failure (4.0%), followed by cardiogenic shock (3.7%), and cardiac arrest (1.7%). The presence of heart failure signs or symptoms had the highest association with the primary outcome (OR:2.16; 95%CI:1.61-2.92). The best cut-off point for this population was 3 (complications risk: 4.0%, SEN:96%, SP:15.4%, NPV:98.1%, PPV:7.9%).

Conclusion: The ACTION ICU score may be a promising tool to identify the need for ICU care in Latin-American patients with NSTEMI. Furthermore, additional research is needed to evaluate the cost-effectiveness of this strategy.