ABC | Volume 113, Nº1, July 2019

Original Article Gil et al Risks scores in acute coronary syndromes Arq Bras Cardiol. 2019; 113(1):20-30 under the auspice of the Portuguese Society of Cardiology. It is an observational, multicentric, nationwide prospective study in which each hospital participates with data from all patients admitted for ACS. The group developed the simple but effective ProACS risk score for predicting in‑hospital mortality, which can be easily applied even in a pre-hospital setting. 3 The objective of this article is to calculate all of the RS in patients admitted for ACS, in a single-centre study. The authors evaluate each RS’s performance in predicting in-hospital mortality and compare them specifically to the ProACS RS. The authors also determine each RS’s performance at predicting worse outcome in STEMI and NSTEMI/UA independently. Finally, the authors access each RS´s ability to predict mortality and recurring ACS at one-year follow-up. Methods This is a retrospective study of patients admitted for ACS to a Coronary Care Unit of a centralized hospital, fromDecember 2006 to May 2016. Only patients presenting with a history of chest pain at rest or other symptoms suggestive of an ACS with or without new significant ST-segment or T-wave changes, new left bundle branch block or elevated biomarkers of myocardial damage were included. Of the 1714 patients included in the study period, 1452 were selected, with the remaining patients being excluded due to missing data. The population sample of this study was not included in the development cohort used to formulate the ProACS risk score, 3 although it has been included in the validation cohorts. The following RS were calculated for all patients: GRACE, TIMI for STEMI, PURSUIT, SRI, EMMACE, C-ACS, CHA 2 DS 2 -VASc-HS, ACTION Registry–GWTG and ProACS. All RS were calculated using data from the initial clinical history, electrocardiogram and laboratory values collected on admission. All patients included were followed up for at least one year or until the occurrence of a major event. The primary endpoint of this study was in-hospital mortality and the combination of all-cause mortality or non-fatal ACS at one-year follow-up. Statistical analysis Categorical variables were characterized by percentages. Group comparisons, with respect to these variables, were performed through chi-square or Fisher’s exact test. Numeric continuous variables were expressed as mean ± standard deviation and RS as median with interquartile range, given their ordinal nature. Group comparisons were achieved through the Mann-Whitney test since the normality assumption was not satisfied for any of the studied numeric variables. Comparative analyses were carried out in relation to demographic variables, therapeutic strategies and general outcome parameters. The RS was evaluated by receiver operating characteristic (ROC) curves, and their area under the curve (AUC), with respect to their ability to differentiate patients with and without adverse clinical events, regarding in‑hospital mortality and the combination of all-causemortality or non-fatal ACS at one-year follow-up. The comparison of AUCs, for each RS with ProACS, was done by the method described by DeLong et al. 15 The Hosmer–Lemeshow Test 16 was used to evaluate the goodness of fit for each risk score. Two-sided p -values are reported and a p‑value < 0.05 was considered statistically significant. Statistical analysis was performed with SPSS version 17.0 (SPSS Inc., Chicago, IL, USA) and MedCalc version 18.2.1 (MedCalc Software, Osted, Belgium). Results Baseline characteristics and univariate predictors of worse outcome A total of 1,452 patients were included in this study. The baseline characteristics are displayed in Table 1. Regarding in-hospital mortality, 6.5% of the patients died. At one-year follow-up, 9.9% of the patients either died or suffered a non-fatal ACS. Table 2 displays the univariate predictors for in-hospital mortality and for all-cause mortality and non-fatal ACS at one-year follow-up. Regarding in-hospital mortality, it is evident that older patients have higher mortality, with chronic kidney disease being associated with a worse prognosis. The clinical presentation also influences the outcome. Lower blood pressure and higher heart rate, as well as higher Killip‑Kimball (KK) class, were linked to a higher mortality rate. It is also evident that lower haemoglobin and higher creatinine, troponin and brain natriuretic peptide values is associated with a worse prognosis, as well as a lower left ventricular ejection fraction. Regarding the occurrence of events at one‑year, follow-up older and female patients tend to have higher mortality. NSTEMI/UA is associated with a worse prognosis. Lower diastolic blood pressure, a higher heart rate and KK class are associated with higher rate of events. Concerning past medical history, diabetes mellitus, chronic kidney disease and previous known coronary disease are associated with a worse outcome. A higher rate of events at 1-year follow-up was seen in patients medicated previously to the index event with statin, renin-angiotensin-aldosterone system inhibitors, beta-blocker and antiplatelet therapy. All RS scored significantly higher in the groups with worse outcome, both in in-hospital mortality and at one-year follow-up. Predictive accuracy of the risk scores Table 3, Table 4 and Table 5 describe the predictive accuracy and goodness of fit of the RS at predicting in-hospital mortality globally, at predicting in-hospital mortality in the specific group of STEMI and NSTEMI/UA patients individually, and at predicting occurrence of all-cause mortality and non‑fatal ACS at one-year follow-up, respectively. The last column of each table show how the other RS compare to the ProACS score. Figure 1 displays the ROC curves regarding the RS and in-hospital mortality. Figure 2 shows in-hospital mortality in the STEMI and NSTEMI group individually. The long-term prognosis is demonstrated in Figure 3. The majority of the RS showed a good discriminatory accuracy to predict in-hospital mortality, as demonstrated by c-statistics consistently over 0.700. Notably, three RS outperformed the others, namely the GRACE, ACTION 21