Faculty Bibliography

Importance:More than 100 million units of blood are collected worldwide each year, yet the indication for red blood cell (RBC) transfusion and the optimal length of RBC storage prior to transfusion are uncertain. Objective:To provide recommendations for the target hemoglobin level for RBC transfusion among hospitalized adult patients who are hemodynamically stable and the length of time RBCs should be stored prior to transfusion. Evidence Review:Reference librarians conducted a literature search for randomized clinical trials (RCTs) evaluating hemoglobin thresholds for RBC transfusion (1950-May 2016) and RBC storage duration (1948-May 2016) without language restrictions. The results were summarized using the Grading of Recommendations Assessment, Development and Evaluation method. For RBC transfusion thresholds, 31 RCTs included 12 587 participants and compared restrictive thresholds (transfusion not indicated until the hemoglobin level is 7-8 g/dL) with liberal thresholds (transfusion not indicated until the hemoglobin level is 9-10 g/dL). The summary estimates across trials demonstrated that restrictive RBC transfusion thresholds were not associated with higher rates of adverse clinical outcomes, including 30-day mortality, myocardial infarction, cerebrovascular accident, rebleeding, pneumonia, or thromboembolism. For RBC storage duration, 13 RCTs included 5515 participants randomly allocated to receive fresher blood or standard-issue blood. These RCTs demonstrated that fresher blood did not improve clinical outcomes. Findings:It is good practice to consider the hemoglobin level, the overall clinical context, patient preferences, and alternative therapies when making transfusion decisions regarding an individual patient. Recommendation 1: a restrictive RBC transfusion threshold in which the transfusion is not indicated until the hemoglobin level is 7 g/dL is recommended for hospitalized adult patients who are hemodynamically stable, including critically ill patients, rather than when the hemoglobin level is 10 g/dL (strong recommendation, moderate quality evidence). A restrictive RBC transfusion threshold of 8 g/dL is recommended for patients undergoing orthopedic surgery, cardiac surgery, and those with preexisting cardiovascular disease (strong recommendation, moderate quality evidence). The restrictive transfusion threshold of 7 g/dL is likely comparable with 8 g/dL, but RCT evidence is not available for all patient categories. These recommendations do not apply to patients with acute coronary syndrome, severe thrombocytopenia (patients treated for hematological or oncological reasons who are at risk of bleeding), and chronic transfusion-dependent anemia (not recommended due to insufficient evidence). Recommendation 2: patients, including neonates, should receive RBC units selected at any point within their licensed dating period (standard issue) rather than limiting patients to transfusion of only fresh (storage length: <10 days) RBC units (strong recommendation, moderate quality evidence). Conclusions and Relevance:Research in RBC transfusion medicine has significantly advanced the science in recent years and provides high-quality evidence to inform guidelines. A restrictive transfusion threshold is safe in most clinical settings and the current blood banking practices of using standard-issue blood should be continued.

Large randomized clinical trials in cardiovascular disease have proliferated over the past 3 decades, with results that have influenced every aspect of cardiology practice. Despite these advances, there remains a substantial need for more high-quality evidence to inform cardiovascular clinical practice, given the increasing prevalence of cardiovascular disease around the world. Traditional clinical trials are increasingly challenging due to rising costs, increasing complexity and length, and burdensome institutional and regulatory requirements. This review will examine the current landscape of cardiovascular clinical trials in the United States, highlight recently conducted registry-based clinical trials, and discuss the potential attributes of the recently launched pragmatic clinical trial by the Patient-Centered Outcomes Research Institute's National Patient-Centered Clinical Research Network, called the ADAPTABLE (Aspirin Dosing: A Patient-centric Trial Assessing the Benefits and Long-term Effectiveness) trial.

This article discusses the controversies surrounding the use of transradial versus transfemoral approaches in the management of patients with ST-segment elevation myocardial infarction, beginning with a review of the benefits of transradial percutaneous coronary intervention (PCI) in this population. The unanswered questions about the mechanism underlying the mortality benefit of transradial PCI are discussed, concluding with recommendations for safe and effective strategies for adoption of the transradial approach to optimize outcomes in these high-risk patients.

Platelets play a key role in mediating stent thrombosis, which is the major cause of ischemic events immediately after percutaneous coronary intervention (PCI). Antiplatelet therapy is therefore the cornerstone of antithrombotic therapy after PCI. However, the use of antiplatelet agents increases bleeding risk, with more potent antiplatelet agents further increasing bleeding risk. In the past 5 years, potent and fast-acting ^P2Y12 inhibitors have augmented the antiplatelet armamentarium available to interventional cardiologists. This article reviews the preclinical and clinical data surrounding these new agents, and discusses the significant questions and controversies that still exist regarding the optimal antiplatelet strategy.