Behavioral Influence of Known Prognostic Markers on the Cardiologist's Decision following Acute Coronary Syndrome: the GRACE Score Paradox / Influência comportamental da predição de risco no processo de decisão do cardiologista: o paradoxo do Escore GRACE

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: ACS patients were consecutively included in this prospective registry. GRACE Score was routinely used by cardiologists 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.

Resumo Fundamento: Cientistas behavioristas ressaltam consistentemente que conhecimento não influencia decisão como esperado. O escore GRACE é um modelo de risco bem validado para prever morte de pacientes com síndromes coronarianas agudas (SCA). Todavia, não se sabe se a avaliação prognóstica pelo GRACE modula decisão médica. Objetivo: Testar a hipótese de que a utilização de escore de risco validado racionaliza a escolha de estratégias invasivas para pacientes de alto risco com SCA sem supradesnivelamento do segmento ST. Métodos: Pacientes com SCA foram consecutivamente incluídos neste registro prospectivo. O escore GRACE foi rotineiramente utilizado pelos cardiologistas como modelo de risco prognóstico. Estratégia invasiva foi definida como decisão imediata de cinecoronariografia, que na conservadora só era indicada se teste não invasivo positivo ou curso instável. Primeiro, avaliamos a associação entre GRACE e invasividade; segundo, a fim de descobrir atuais determinantes da estratégia invasiva, construímos um modelo de propensão para ela. Foi considerado significante um valor de p < 0,05 para esta análise. Resultados: Em amostra de 570 pacientes, estratégia invasiva foi adotada para 394 (69%). O escore GRACE foi de 118 ± 38 para o grupo invasivo, semelhante a 116 ± 38 do conservador (p = 0,64). O escore de propensão para estratégia invasiva foi derivado da regressão logística: troponina positiva e desvio de ST (associações positivas) e hemoglobina (associação negativa). Esse escore predisse estratégia invasiva com estatística-c de 0,68 (IC95%: 0,63-0,73), contrariando o Escore GRACE (AUC 0,51; IC95%: 0,47-0,57). Conclusão: A dissociação observada entre o valor do Escore GRACE e decisão invasiva em SCA sugere que o pensamento probabilístico pode não ser um importante determinante da decisão médica.

Option for the radial versus femoral access in coronary intervention in acute coronary syndromes: a risk-treatment paradox / Opção para o acesso radial versus femoral na intervenção coronária em síndromes coronárias agudas: um paradoxo de tratamento de risco

Background: In coronary procedures, although the radial approach protects patients from hemorrhagic complications, it is technically more complex than the femoral approach. Objectives: To test the hypothesis that the radial approach is the procedure of choice in ACS patients due to the high risk of bleeding; and to identify independent predictors of the choice for radial access. Methods: Patients admitted for ACS who underwent invasive coronary procedure were included. We registered the type of access (femoral or radial) chosen by the physician for the first angiography; the investigators did not interfere with this choosing process. Student's t-test was used for comparisons between the CRUSADE and ACUITY scores. Predictors of radial access were compared between the groups. Statistical significance was defined by p < 0,05.Results: Radial access was chosen in 67% of 347 consecutive patients. Patients who underwent radial approach had lower risk of bleeding determined by CRUSADE (30 ± 14 vs. 37 ± 15; p < 0.001) as compared with femoral access. In multivariate analysis, four variables were identified as independent predictors negatively associated with radial access ­ age (OR = 0.98; 95%CI = 0.96 ­ 0.99), creatinine (OR = 0.54; 95%CI = 0.3 ­ 0.98), signs of left ventricular failure (OR = 0.45; 95% CI = 0.22 ­ 0.92) and previous CABG (OR = 0.022; 95%CI = 0.003 ­ 0.166). Conclusion: The propensity to choose radial over femoral access in coronary intervention was not primarily influenced by patients' bleeding risk. Predictors of this decision, identified in the study, indicated less complex patients, suggesting that the difficulty in performing the technique was a stronger determinant than its potential antihemorrhagic effect