Ep 128 - Can we use diagnostic probability to guide treatment thresholds in ACS with Charlie Reynard and Rick Body

Optimizing Anti-Platelet Therapy in Acute Coronary Syndromes: Insights from St. Emlyn’s Welcome back to the St. Emlyn’s blog! Today, we're delving into optimizing anti-platelet therapy for patients with suspected acute coronary syndromes (ACS), inspired by Dr. Charlie Raynard's research during his academic foundation program. His work provides valuable insights for managing ACS in emergency departments. Let's explore the study and its implications. The Foundation of the Research Dr. Charlie Raynard, working in Manchester, is pursuing a PhD focusing on innovations to manage patients with suspected ACS in emergency departments. His project, culminating in the paper titled "Optimizing Anti-Platelet Utilisation in Acute Care Settings," was accepted by the Emergency Medicine Journal (EMJ) and offers crucial findings that can impact clinical practice. You can find the full paper on our website. This research is particularly relevant for emergency medicine practitioners frequently encountering ACS patients. Managing Uncertainty in Emergency Medicine Emergency medicine often involves making decisions under uncertainty, treating conditions based on probable diagnoses rather than confirmed ones. This approach requires weighing the risks and benefits of treatment without complete information, crucial for improving patient outcomes. Treating Sepsis Without Confirmation When a patient presents with symptoms suggesting sepsis, we start treatment before confirming the diagnosis through blood cultures. The potential consequences of untreated sepsis—such as death—are so severe that we initiate antibiotics to mitigate the risk. Deep Vein Thrombosis and Pulmonary Embolism Similarly, in suspected deep vein thrombosis (DVT) or pulmonary embolism (PE), we may start treatment with low molecular weight heparin based on a high Wells score and a positive D-dimer test before imaging confirms the diagnosis. These examples highlight the necessity of making informed decisions despite the lack of definitive evidence. Internal Modeling of Uncertainty In these scenarios, we internally model the condition's risk against the treatment's benefits and risks. This process, though not always explicit, guides decision-making. However, this subjective approach can sometimes lead to risk-averse decisions where treatment may be initiated even when the objective benefits are unclear. Objective Assessment of Risks and Benefits Dr. Raynard's research aims to address this issue by objectively assessing the risks and benefits of different anti-platelet therapies for patients with suspected ACS. The goal is to develop a model that helps clinicians make more informed decisions under uncertainty, enhancing care quality and patient outcomes. The Systematic Review Process The first step was to collect data to inform the model. Dr. Raynard and his team conducted systematic reviews to evaluate the benefits of clopidogrel versus ticagrelor, both in combination with aspirin, in treating ACS. These reviews provided a foundation of evidence for the decision-making model. Understanding Patient Utility The team also sought to understand patient preferences and outcomes, a concept known as utility. They reviewed research that quantified patient utility for various ACS-related outcomes. This patient-centered measure is crucial for developing a model that accurately reflects real-world clinical decisions, aligning with patient values and needs. Building the Decision Tree Model The next phase involved building a decision tree model, a simple yet effective tool for modeling different clinical outcomes. The model included various branches representing possible outcomes, such as whether a patient had ACS, received anti-platelet therapy, experienced bleeding, or had a stroke. Probabilities and Patient Preferences Using data from the systematic reviews, the team calculated the probabilities of each outcome. They combined these probabilities with patient utility measures to assess the