Analysis of Anemia, Transfusions, and CABG Outcomes in The Society of Thoracic Surgeons National Database

The Society of Thoracic Surgeons Adult Cardiac Surgery Database: 2024 Update on National Trends and Outcomes

The Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database (ACSD) is the most robust and advanced clinical database in cardiac surgery. With more than 8.3 million procedures and more than 1000 participating institutions encompassing more than 97% of cardiac surgery in the United States, the ACSD is the specialty's vital instrument for quality improvement, patient safety, and outcome reporting in cardiac surgery. The database continues to advance initiatives to achieve these goals, which recently have included adding new risk models for multivalve procedures, isolated tricuspid valve surgery, aortic valve replacement after transcatheter aortic valve replacement, and mitral valve surgery for degenerative mitral regurgitation. In addition, the ACSD can now provide longitudinal survival data through linkage to the National Death Index. This report reviews current trends in the ACSD through the end of 2023, impactful research during the past year, and database innovations being implemented.

How do I analyze the role of red blood cell transfusions on clinical outcome in anemic patients? Disentangling the effect of red blood cell transfusions from pre-operative anemia on post-operative outcome

BACKGROUND

Preoperative anemia is associated with worse clinical postoperative outcomes and a higher risk of receiving red blood cell (RBC) transfusions. It is challenging to disentangle the effect of preoperative anemia from the effect of receiving RBC transfusions on postoperative clinical outcomes such as length of hospital stay (LOS). When analyzing the association of preoperative anemia on LOS, it is important to be able to analyze RBC transfusions as a mediator in this relationship. In this paper, the background and application of mediation analysis is outlined as a statistical methodology in transfusion medicine research.

STUDY DESIGN AND METHODS

To explain the methodology of mediation analysis, a database from a previously reported clinical study was used (So-Osman C. et al. 2014) with anemia as the exposure variable and LOS as the primary outcome. Both the product-of-coefficients method and the change-in-coefficients method are used for mediation analysis, and linear regression models were used.

RESULTS

In the example of a simplified analysis, two-thirds of the effect could be attributed to mediation. This result was obtained by both the product-of-coefficients method and the change-in-coefficients method.

DISCUSSION

Mediation is assessed in a similar way as confounding, but the interpretation of the results is totally different. It is, therefore, of critical importance to distinguish between potential mediators and potential confounders in transfusion research. Since the calculation reported in the results is merely used as an example to show the methodology, e.g. ignoring confounding, the result should not be interpreted as scientific research data.

Design and Staged Implementation of a Multidisciplinary Preoperative Anemia Clinic at a Tertiary Care Medical Center

BACKGROUND

Preoperative anemia is common and associated with adverse outcomes in surgical patients. There is limited information to guide the design and implementation of preoperative anemia clinics (PAC), which represents a critical barrier to entry for many practices.

METHODS

This is a descriptive observational study highlighting the design and implementation of a multidisciplinary PAC, including key steps in planning, stakeholder engagement, organizational structure, identification of target populations, establishing anemia treatments, information technology and electronic health record integration, provider training, and data infrastructure. Demographic and clinical characteristics, laboratory results, and anemia treatments for individuals evaluated in the PAC from November 4, 2019 through September 15, 2023 are enumerated. Patient-reported outcomes (PROs) assessing changes in anemia symptoms and well-being after surgery are evaluated for 2 subsets of patients (one before PAC implementation [pre-PAC], another after PAC implementation [post-PAC]), without formal statistical comparison given limited sample sizes.

RESULTS

The PAC was initiated as a multidisciplinary effort under support from a Mayo Clinic Practice Transformation Award in 2019, including broad representation from anesthesiology, surgery, and medical practices, along with institutional project management support (eg, project manager, information technologists, systems engineers). While initially limited to cardiac surgery patients, the PAC underwent planned incremental expansion to include other surgical services. Over the study period, 1188 PAC consultations across 1159 unique patients met eligibility criteria, with a median age of 66 (57-73) years and 58.1% women. The most common etiology of anemia was iron deficiency (69.1%) followed by anemia related to cancer (17.3%). Anemia-directed therapies were recommended in 1038 (87.4%) encounters, with 730 (70.3%) of those receiving recommended treatment preoperatively. Seven hundred nine (97.1%) treatments included intravenous iron and 146 (20.0%) included erythropoiesis-stimulating agents. Fifteen pre-PAC and 38 post-PAC implementation patients completed PROs. PAC implementation was accompanied by earlier resolution of anemia symptoms and less pronounced declines in postoperative well-being scores.

CONCLUSIONS

This report highlights the key steps for successful PAC implementation. Treatment is possible for most patients and may be accompanied by improvements in patient-important outcomes.

The Year in Cardiothoracic and Vascular Anesthesia: Selected Highlights from 2024

This special article is the 17th in an annual series for the Journal of Cardiothoracic and Vascular Anesthesia. The authors thank the editor in chief, Dr Kaplan, and the editorial board for the opportunity to continue this series, namely, the research highlights of the past year in the specialty of cardiothoracic and vascular anesthesiology.1 The major themes selected for 2024 are outlined in this introduction, and each highlight is reviewed in detail in the main article. The literature highlights in the specialty for 2024 begin with an update on perioperative rehabilitation and enhanced recovery in cardiothoracic surgery, with a focus on novel methods to best assess our patients in the preoperative period and the impact of implementing enhanced recovery care models on outcomes. The second major theme is focused on cardiac surgery, with the authors discussing new insights into anemia, transfusions, and coronary artery bypass grafting outcomes with a focus on gender disparities. The third theme is focused on cardiothoracic transplantation, with discussions focusing on techniques related to lung transplantation, including mechanical circulatory support. The 4th theme is focused on mechanical circulatory support, with discussions exploring advancements in left ventricular assist devices highlight the evolving landscape of mechanical circulatory support and discussion of anticoagulation practices. The fifth and final theme is an update on medical cardiology, with a focus on the outcomes of transcatheter management of regurgitant pathology, device management in heart failure, and new techniques in catheter ablation. The themes selected for this article are only a few of the diverse advances in the specialty during 2024. These highlights will inform the reader of key updates on a variety of topics, leading to improvement in perioperative outcomes for patients with cardiothoracic and vascular disease.

Effect of mild hypothermia vs normothermia cardiopulmonary bypass on postoperative bleeding in patients undergoing coronary artery bypass grafting: protocol of a multi-center, randomized, controlled trial

BACKGROUND

Coronary artery bypass grafting (CABG) is often performed with hypothermic cardiopulmonary bypass (CPB) to reduce metabolic demands and protect the myocardium. However, hypothermia can increase bleeding risks and other complications.

METHODS

This is a prospective, multi-center, randomized controlled trial. From September 2023 to December 2024, a total of 336 eligible patients planning to undergo on-pump CABG will be enrolled. All participants will be randomly divided into mild hypothermia CPB group (target oxygenator arterial outlet blood temperature at 32-33℃) or normothermia CPB group (target oxygenator arterial outlet blood temperature at 35-36℃). The primary endpoint is Universal Definition of Perioperative Bleeding (UDPB) class 2-4. Secondary endpoints are class of UDPB, levels of coagulation and inflammatory factors, in-hospital mortality, perioperative related complications, ICU length of stay, and hospital length of stay.

DISCUSSION

This clinical trial aims to compare the effects of different target temperature during CPB on postoperative bleeding and to explore optimal temperature strategy to provide new clinical evidence.

TRIAL REGISTRATION

Chictr.org.cn : ChiCTR2300075405. The trial was prospectively registered on 4 September 2023.