Evaluation of the Canadian Clinical Practice Guidelines Risk Prediction Tool for Acute Aortic Syndrome: The RIPP Score.

Introduction: Acute aortic syndrome (AAS) is a rare clinical syndrome with a high mortality rate. The Canadian clinical practice guideline for the diagnosis of AAS was developed in order to reduce the frequency of misdiagnoses. As part of the guideline, a clinical decision aid was developed to facilitate clinician decision-making (RIPP score). The aim of this study is to validate the diagnostic accuracy of this tool and assess its performance in comparison to other risk prediction tools that have been developed. Methods: This was a historical case-control study. Consecutive cases and controls were recruited from three academic emergency departments from 2002-2020. Cases were identified through an admission, discharge, or death certificated diagnosis of acute aortic syndrome. Controls were identified through presenting complaint of chest, abdominal, flank, back pain, and/or perfusion deficit. We compared the clinical decision tools' C statistic and used the DeLong method to test for the significance of these differences and report sensitivity and specificity with 95% confidence intervals. Results: We collected data on 379 cases of acute aortic syndrome and 1340 potential eligible controls; 379 patients were randomly selected from the final population. The RIPP score had a sensitivity of 99.7% (98.54-99.99). This higher sensitivity resulted in a lower specificity (53%) compared to the other clinical decision aids (63-86%). The DeLong comparison of the C statistics found that the RIPP score had a higher C statistic than the ADDRS (-0.0423 (95% confidence interval -0.07-0.02); P < 0.0009) and the AORTAs score (-0.05 (-0.07 to -0.02); P = 0.0002), no difference compared to the Lovy decision tool (0.02 (95% CI -0.01-0.05 P < 0.25)) and decreased compared to the Von Kodolitsch decision tool (0.04 (95% CI 0.01-0.07 P < 0.008)). Conclusion: The Canadian clinical practice guideline's AAS clinical decision aid is a highly sensitive tool that uses readily available clinical information. It has the potential to improve diagnosis of AAS in the emergency department.

Does implementation of a diagnostic pathway for acute aortic syndrome including D-dimer increase the usage of D-dimer and computed tomography?

INTRODUCTION: The Canadian clinical practice guidelines propose a novel diagnostic pathway incorporating a clinical decision tool and D-dimer to aid in risk stratifying patients for acute aortic syndrome. The objective of this study was to assess if implementation of a diagnostic pathway incorporating D-dimer would increase the usage of D-dimer and computed tomography (CT) in a tertiary care emergency department. METHODS: Prospective single centre before and after study-recruiting patients over a 6-week period from a tertiary care emergency department. INTERVENTION: multi model implementation of a diagnostic pathway for acute aortic syndrome incorporating D-dimer. OUTCOME: proportion of patients receiving D-dimer testing/CT in the 2 weeks before and after implementation. RESULTS: We included 982 patients (Female 55%, Age mean 51.9, N = 492 pre intervention and N = 490 post intervention). The proportion that received a D-dimer test increased from 6.9 to 10.4% (p < 0.051), while the number of CT aortas remained stable (0.6% vs. 0.6%; p = 0.60). Documentation of pretest probability assessment increased from 1 to 3%, (p < 0.009) following the intervention. In the post intervention cohort, the tool was applied correctly in all cases (N = 17). CONCLUSION: This single centre study found that a diagnostic pathway for acute aortic syndrome including D-dimer could be implemented without a significant increase in test ordering during this first 2 weeks after implementation. This study adds to the argument for use of D-dimer to help risk stratify patients for the diagnosis of acute aortic syndrome. Future studies are needed to confirm the diagnostic accuracy of this pathway and the long-term impact on resource utilization.

RéSUMé: INTRODUCTION: Les guides de pratique clinique canadiens proposent une nouvelle voie de diagnostic intégrant un outil de décision clinique et du D-dimère pour aider à stratifier le risque chez les patients atteints du syndrome aortique aigu. L'objectif de cette étude était d'évaluer si la mise en place d'une voie diagnostique intégrant le dimère-D augmenterait l'utilisation du dimère-D et de la tomodensitométrie (TDM) dans un service d'urgence de soins tertiaires. MéTHODES: Centre unique prospectif avant et après l'étude - recrutement de patients sur une période de 6 semaines à partir d'un service d'urgence de soins tertiaires. Intervention : mise en œuvre multi-modèle d'une voie diagnostique pour le syndrome aortique aigu intégrant le D-dimère. Résultat : Proportion de patients ayant subi un test des D-dimères/TDM dans les deux semaines précédant et suivant la mise en œuvre. RéSULTATS: Nous avons inclus 982 patients (femmes 55 %, âge moyen 51,9, N = 492 avant l'intervention et N = 490 après l'intervention). La proportion de personnes ayant reçu un test D-dimère est passée de 6,9 % à 10,4 % (p < 0,051), tandis que le nombre d'aortes CT est demeuré stable (0,6 % contre 0,6 %; p = 0,60). La documentation de l'évaluation de la probabilité avant le test est passée de 1 % à 3 % (p<0,009) après l'intervention. Dans la cohorte post-intervention, l'outil a été appliqué correctement dans tous les cas (n = 17). CONCLUSION: Cette étude menée auprès d'un seul centre a révélé qu'une voie diagnostique pour le syndrome aortique aigu, y compris le D-dimère, pourrait être mise en œuvre sans qu'il y ait une augmentation significative de l'ordre des tests au cours des deux premières semaines suivant la mise en œuvre. Cette étude renforce l'argument en faveur de l'utilisation du D-dimère pour aider à stratifier les risques des patients pour le diagnostic du syndrome aortique aigu. De futures études sont nécessaires pour confirmer la précision du diagnostic de cette voie et l'impact à long terme sur l'utilisation des ressources.