I have always emphasized the need for multidisciplinary, representative blood utilization committees as part of a comprehensive patient blood management program. To that end, it is important to have representation from the “bloody specialties”, including cardiac surgery, orthopedic surgery, anesthesiology, critical care, hospitalists, and hematology-oncology.
Based upon recent trends in the transfusion literature, it has become evident that also involving cardiologists in blood utilization committees as well as blood management teams is essential.
I wrote a blog in November 2010 titled “The Heartbreak of Blood Transfusions.” The blog discussed the physiology of myocardial oxygen supply and demand and the need for higher hemoglobin levels in patients with ischemic heart disease. This places patients with cardiac disease at increased risk for the adverse effects of anemia, but does not in itself prove that transfusions are beneficial. There are a growing number of transfusion trials in high risk patients noting that restrictive transfusion thresholds for red blood cells are at least as effective, if not superior, to more liberal strategies, and the AABB recently published a nice consensus document summarizing the evidence.1 This document did not make a recommendation on transfusion strategies for patients with active cardiac disease because of a lack of prospective randomized data. However, there is growing evidence from observational studies that liberal transfusions may increase mortality in patients with acute coronary syndromes (ACS),2–4 and there is a pilot study of transfusion strategies in ACS patients currently underway known as the MINT trial. While we await the results of the MINT trial, we should certainly be cautious about reflex transfusions for patients with ACS given the pro-inflammatory and pro-coagulant effects of stored blood, and a single unit approach in non-bleeding patients is warranted.
In addition to the ongoing concern about evidence based transfusion practice in patients with cardiac disease, a couple of recent articles raise concern in two other cardiology- related areas that are high impact to most hospitals. Specifically, these areas of concern are the evolving risk- benefit ratio of new anticoagulant drugs, and the impact of bleeding complications in the cardiac catheterization lab.
There are a growing number of drugs entering the marketplace that reduce thrombotic complications, and many of these drugs are used by cardiologists. Patients who have valvular heart disease and/ or atrial fibrillation are at greatly increased risk of stroke due to clots formed in the heart that pass to the cerebral circulation. Patients who have coronary vascular disease, or who have had coronary stents placed to treat coronary vascular disease, are at significant risk of coronary occlusion and death. As our population ages, both of these patient groups are increasing in number so the demand for newer and more potent anticoagulant agents is also increasing. Key among these new anticoagulant drugs are oral activated factor Xa antagonists and direct thrombin inhibitors. In the rush to produce these new drugs, it would seem that more attention has been focused on convenience and efficacy than on potential risks to patients. Many of these drugs tout the benefits of a long half-life and the reduced need for laboratory monitoring. However, when patients present to the ER with a GI bleed or to surgery with a bleeding complication from these drugs, the inability to accurately diagnose and treat bleeding can lead to significant harm. Bleeding complications due to anticoagulant medications have become a leading cause of ER visits in Medicare patients, raising safety and cost issues. A recent review of seven clinical trials involving over 31,000 patients questioned the net clinical benefit of these new drugs. Using pooled data from these studies, the authors noted significant but moderate reductions in the risk for stent thrombosis or composite ischemic events compared to placebo, but there was no significant reduction in overall mortality. Another key finding was that there was a dramatic effect on bleeding complications in treated patients, with a 300% increase in major bleeding events. They concluded “The use of anti-Xa or direct thrombin inhibitors is associated with a dramatic increase in major bleeding events, which might offset all ischemic benefits in patients receiving antiplatelet therapy after ACS.”5 Recognizing the significant impact of these drugs on bleeding complications in surgical patients, the Society of Thoracic Surgeons just published an updated guideline on the use of these drugs in the perioperative period.6
In my previous blog I also discussed the risk and consequences of bleeding during heart catheterization, also known as percutaneous coronary intervention (PCI). I pointed to a review of 90,000 PCI procedures that concluded patients with a bleeding complication requiring a blood transfusion had a 350% increase in mortality, and that this bleeding-related mortality was greater than the risk of death from an MI during the procedure.7 I have found this article useful to circulate to cardiologists because it has an expanded discussion of the possible mechanisms of this increased mortality, keying on the physiology of ACS and the physical properties of stored blood. Another study published earlier this year reviewed data from 2600 ST-segment elevation myocardial infarction (STEMI) patients undergoing PCI also concluded that blood transfusion independently increased in-hospital mortality, long term morbidity and length of stay.8 Both of these studies emphasized that the best strategy is primary prevention to reduce bleeding complications in PCI patients. To that end, the final article to mention was a review of the effects of radial artery (wrist) vs. femoral artery (groin) access in patients with ACS. The RIVAL trial was a multinational prospective study of radial vs. femoral PCI in 7021 patients with either ST-elevation MI (STEMI) or non-ST-segment elevation ACS (NSTEACS). There was a substantial reduction in major vascular access site complications in the radial group, although there was no overall significant reduction in the primary composite outcome of death, MI, stroke or major bleeding when combining data from STEMI and NSTEACS patients. However, when the two patient groups were evaluated separately, those patients with STEMI undergoing a radial PCI had a 40% decrease in composite morbidity and mortality and a 61% decrease in all-cause mortality. The authors theorized that STEMI patients benefit more from the radial approach because they are exposed to more potent antithrombotic therapies and have a higher risk-adjusted rate of bleeding complications. They also noted that the benefit was independent of radial artery catheterization operator experience and center procedural volume, making radial artery access the preferred option in patients with STEMI.9 There is no doubt that retraining cardiologists to perform radial artery PCI requires an investment in time and money, but there is growing evidence that the effort is worthwhile both from a patient safety and cost standpoint.
- Carson JL, Grossman BJ, Kleinman S, et al. Red Blood Cell Transfusion: A Clinical Practice Guideline From the AABB*. Annals of internal medicine. 2012;157(1):49–58.
- Rao SV, Kaul PR, Liao L, et al. Association between bleeding, blood transfusion, and costs among patients with non-ST-segment elevation acute coronary syndromes. American heart journal. 2008;155(2):369–74.
- Aronson D, Dann EJ, Bonstein L, et al. Impact of red blood cell transfusion on clinical outcomes in patients with acute myocardial infarction. The American journal of cardiology. 2008;102(2):115–9.
- Shishehbor MH, Madhwal S, Rajagopal V, et al. Impact of blood transfusion on short- and long-term mortality in patients with ST-segment elevation myocardial infarction. JACC. Cardiovascular interventions. 2009;2(1):46–53.
- Komócsi A, Vorobcsuk A, Kehl D, Aradi D. Use of New-Generation Oral Anticoagulant Agents in Patients Receiving Antiplatelet Therapy After an Acute Coronary Syndrome: Systematic Review and Meta-analysis of Randomized Controlled Trials. Archives of internal medicine. 2012:1–9.
- Ferraris V a, Saha SP, Oestreich JH, et al. 2012 update to the society of thoracic surgeons guideline on use of antiplatelet drugs in patients having cardiac and noncardiac operations. The Annals of thoracic surgery. 2012;94(5):1761–81.
- Doyle BJ, Rihal CS, Gastineau D a, Holmes DR. Bleeding, blood transfusion, and increased mortality after percutaneous coronary intervention: implications for contemporary practice. Journal of the American College of Cardiology. 2009;53(22):2019–27.
- Ergelen M, Uyarel H, Altay S, et al. Prognostic impact of red blood cell transfusion in patients undergoing primary angioplasty for ST elevation myocardial infarction. Coronary artery disease. 2012;(Dm):1–6.
- Mehta SR, Jolly SS, Cairns J, et al. Effects of Radial Versus Femoral Artery Access in Patients With Acute Coronary Syndromes With or Without ST-Segment Elevation. Journal of the American College of Cardiology. 2012;xx(x).