ABC | Volume 112, Nº6, June 2019

Original Article Behavioral Influence of Known Prognostic Markers on the Cardiologist’s Decision following Acute Coronary Syndrome: the GRACE Score Paradox Manuela Campelo Carvalhal, 1 T hiago Menezes Barbosa de Souza, 1 J essica Suerdieck, 1 Fernanda Lopes, 1 Vitor Calixto de Almeida Correia, 1 Yasmin Falcon Lacerda, 1 N icole de Sá, 1 G abriella Sant’Anna Sodré, 1 Marcia Maria Noya Rabelo, 2 L uis Cláudio Lemos Correia 2 Escola Bahiana de Medicina e Saúde Pública, 1 Salvador, BA – Brazil Hospital São Rafael, Fundação Monte Tabor, 2 Salvador, BA – Brazil Mailing Address: Luís Cláudio Lemos Correia • Av. Princesa Leopoldina, 19/402. Posyal Code 40150-080, Graça, Salvador, BA – Brazil E-mail: lccorreia@cardiol.br , lccorreia@terra.com.br Manuscript received June 07, 2018, revised manuscript August 28, 2018, accepted September 19, 2018 DOI: 10.5935/abc.20190046 Abstract Background: Behavioral scientists consistently point out that knowledge does not influence decisions as expected. GRACE Score is a well validated risk model for predicting death of patients with acute coronary syndromes (ACS). However, whether prognostic assessment by this Score modulates medical decision is not known. Objective: To test the hypothesis that the use of a validated risk score rationalizes the choice of invasive strategies for higher risk patients with non-ST-elevation ACS. Methods: ACSpatientswereconsecutively included in thisprospective registry.GRACEScorewas routinelyusedbycardiologists as the prognostic risk model. An invasive strategy was defined as an immediate decision of the coronary angiography, which in the selective strategy was only indicated in case of positive non-invasive test or unstable course. Firstly, we evaluated the association between GRACE and invasiviness; secondly, in order to find out the actual determinants of the invasive strategy, we built a propensity model for invasive decision. For this analysis, a p-value < 0.05 was considered as significant. Results: In a sample of 570 patients, an invasive strategy was adopted for 394 (69%). GRACE Score was 118 ± 38 for the invasive group, similar to 116 ± 38 for the selective group (p = 0.64). A propensity score for the invasive strategy was derived from logistic regression: positive troponin and ST-deviation (positive associations) and hemoglobin (negative association). This score predicted an invasive strategy with c-statistics of 0.68 (95%CI: 0.63-0.73), opposed to GRACE Score (AUC 0.51; 95%CI: 0.47-0.57). Conclusion: The dissociation between GRACE Score and invasive decision in ACS suggests that the knowledge of prognostic probabilities might not determine medical decision. (Arq Bras Cardiol. 2019; 112(6):721-726) Keywords: Acute Coronary Syndrome; Prognosis; Non-ST Elevation Myocardial Infarction. Introduction The risk-treatment paradox is a common phenomenon in which, contrary to what is expected, patients with higher risk receive less aggressive treatment as compared with individuals with lower risk. 1 One of the causes of this paradox is an equivocal risk evaluation based on the physician's intuitive impression. Probabilistic risk models have shown to be more accurate than intuitive judgment, suggesting that the use of such models theoretically facilitates prognosis-based treatment choice. 2-4 However, behavioral scientists have demonstrated that knowledge does not modulate decisions as expected. 5 In economy, people tend to make irrational decisions, which is not different in health-related issues. For example, it is well known smoking or obesity are risk factors for serious diseases, but habits of smoking, or eating improperly are common. Therefore, whether the use of a risk score actually modulates the physician’s decision is unknown. Non-ST-segment elevation acute coronary syndromes (ACS) present with a wide spectrum of risks, and patients can be treated in a conservative or aggressive manner. 6,7 This is one of the main clinical scenarios in which the risk-treatment paradox has been described. 8 Even though GRACE Score is a well-validated risk model for patients with ACS, its actual impact on providing a more reasonable approach according to risk, and on its relationship with medical judgment, has yet to be demonstrated. 9,10 Our aim was to test the hypothesis that the utilization of a risk score rationalizes the choice for invasive strategies towards higher risk patients with with non‑ST elevation acute coronary syndromes. 721