International variation in the use of blood transfusion in patients with non-ST-segment elevation acute coronary syndromes

Institutional Red Blood Cell Transfusion Rates Are Correlated Following Endovascular and Surgical Cardiovascular Procedures: Evidence That Local Culture Influences Transfusion Decisions

Background

The relationship between local hospital culture and transfusion rates following endovascular and surgical cardiovascular procedures has not been well studied.

Methods and Results

Patients undergoing coronary revascularization, aortic valve replacement, lower extremity peripheral vascular intervention, or carotid artery revascularization from up to 852 US hospitals in the Nationwide Readmissions Database were identified. Crude and risk‐standardized red blood cell transfusion rates were determined for each procedure. Pearson correlation coefficients were calculated between respective procedural transfusion rates. Median odds ratios were estimated to reflect between‐hospital variability in red blood cell transfusion rates following the same procedure for a given patient. There was wide variation in red blood cell transfusion rates across different procedures, from 2% following carotid endarterectomy to 29% following surgical aortic valve replacement. For surgical and endovascular modalities, transfusion rates at the same hospital were highly correlated for aortic valve replacement (r=0.67; P<0.001), moderately correlated for coronary revascularization (r=0.56; P<0.001) and peripheral vascular intervention (r=0.51; P<0.001), and weakly correlated for carotid artery revascularization (r=0.19, P<0.001). Median odds ratios were all >2, highest for coronary artery bypass graft surgery and surgical aortic valve replacement, indicating substantial site variation in transfusion rates.

Conclusions

After adjustment for patient‐related factors, wide variation in red blood cell transfusion rates remained across surgical and endovascular procedures employed for the same cardiovascular condition. Transfusion rates following these procedures are highly correlated at individual hospitals and vary widely across hospitals. In aggregate, these findings suggest that local institutional culture significantly influences the decision to transfuse following invasive cardiovascular procedures and highlight the need for randomized data to inform such decisions.

Blood utilization in five Chinese hospitals shows low hemoglobin thresholds in medical patients

BACKGROUND

The number of red blood cell units transfused per capita in China is lower than in western countries and the reason(s) for the difference is unknown.

STUDY DESIGN AND METHODS

We randomly chose 5050 transfused patients from five Chinese hospitals. We compared transfused cases to nontransfused controls matched for the same underlying diagnosis. We assessed the pretransfusion hemoglobin (Hb) trigger and other clinical characteristics associated with transfusion. After stratifying by underlying disease, we compared pretransfusion Hb level in Chinese hospitals to 12 US hospitals.

RESULTS

In 5050 patients who received transfusion, the pretransfusion Hb levels were lower in medical (6.3 g/dL) compared to surgical patients receiving transfusion postoperatively (8.1 g/dL). In patients with nonsurgical diagnoses, the pretransfusion Hb was much lower than that in the United States; the difference in mean Hb level varied by underlying diagnosis from 0.4 to 1.8 g/dL. In case-control analysis of cases (n = 1356) compared to controls (n = 1201), the pretransfusion Hb showed the strongest association with transfusion. Compared to 10 g/dL, the odds ratio (95% confidence interval) for pretransfusion Hb of 7 to 7.9 g/dL was 37.7 (24.8-57.4).

CONCLUSION

Transfusion triggers in five Chinese hospitals appear comparable to those in the United States for surgical patients; however, medical patients have lower pretransfusion Hb levels (approx. 6 g/dL). Of the factors assessed, the pretransfusion Hb was most strongly associated with transfusion. The clinical impact of lower transfusion thresholds used in China is unknown.

Development and Validation of a Novel Risk Score for In-Hospital Major Bleeding in Acute Myocardial Infarction:-The SWEDEHEART Score

Background Bleeding risk stratification in acute coronary syndrome is of highest clinical interest but current risk scores have limitations. We sought to develop and validate a new in-hospital bleeding risk score for patients with acute myocardial infarction. Methods and Results From the nationwide SWEDEHEART (Swedish Web-System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies) register, 97,597 patients with acute myocardial infarction enrolled from 2009 until 2014 were selected. A full model with 23 predictor variables and 8 interaction terms was fitted using logistic regression. The full model was approximated by a model with 5 predictors and 1 interaction term. Calibration, discrimination, and clinical utility was evaluated and compared with the ACTION (Acute Coronary Treatment and Intervention Outcomes Network) and CRUSADE (Can Rapid Risk Stratification of Unstable Angina Patients Suppress Ad verse Outcomes With Early Implementation of the ACC /AHA Guidelines) scores. Internal and temporal validity was assessed. In-hospital major bleeding, defined as fatal, intracranial, or requiring surgery or blood transfusion, occurred in 1356 patients (1.4%). The 5 predictors in the approximate model that constituted the SWEDEHEART score were hemoglobin, age, sex, creatinine, and C-reactive protein. The ACTION and CRUSADE scores were poorly calibrated in the derivation cohort and therefore were recalibrated. The SWEDEHEART score showed higher discriminative ability than both recalibrated scores, overall ( C-index 0.80 versus 0.73/0.72) and in all predefined subgroups. Decision curve analysis demonstrated consistently positive and higher net benefit for the SWEDEHEART score compared with both recalibrated scores across all clinically relevant decision thresholds. The original ACTION and CRUSADE scores showed negative net benefit. Conclusions The 5-item SWEDEHEART score discriminates in-hospital major bleeding in patients with acute myocardial infarction and has superior model performance compared with the recalibrated ACTION and CRUSADE scores.

Economic considerations on transfusion medicine and patient blood management

In times of escalating health-care cost, it is of great importance to carefully assess the cost-effectiveness and appropriateness of the most resource-consuming health interventions. A long-standing and common clinical practice that has been underestimated in cost and overestimated in effectiveness is the transfusion of allogeneic blood products. Studies show that this intervention comes with largely underestimated service cost and unacceptably high utilisation variability for matched patients, thus adding billions of unnecessary dollars to the health-care expenditure each year. Moreover, a large and increasing body of literature points to a dose-dependent increase of morbidity and mortality and adverse long-term outcomes associated with transfusion whereas published evidence for benefit is extremely limited. This means that transfusion may be a generator for increased hospital stay and possible re-admissions, resulting in additional billions in unnecessary expenditure for the health system. In contrast to this, there are evidence-based and cost-effective treatment options available to pre-empt and reduce allogeneic transfusions. The patient-specific rather than a product-centred application of these multiple modalities is termed patient blood management (PBM). From a health-economic perspective, the expeditious implementation of PBM programmes is clearly indicated. Both patients and payers could benefit from this concept that has recently been endorsed through the World Health Assembly resolution WHA63.12.

Evaluation and management of anemia in the elderly

Anemia is now recognized as a risk factor for a number of adverse outcomes in the elderly, including hospitalization, morbidity, and mortality. What constitutes appropriate evaluation and management for an elderly patient with anemia, and when to initiate a referral to a hematologist, are significant issues. Attempts to identify suggested hemoglobin levels for blood transfusion therapy have been confounded for elderly patients with their co-morbidities. Since no specific recommended hemoglobin threshold has stood the test of time, prudent transfusion practices to maintain hemoglobin thresholds of 9-10 g/dL in the elderly are indicated, unless or until evidence emerges to indicate otherwise.

Effect of hospital culture on blood transfusion in cardiac procedures

BACKGROUND

In our effort to reduce the use of blood products in cardiac operations in a health care system, we noted variations in transfusion practices among facilities. Interestingly, surgeons practicing at the same hospital had similar transfusion rates. We sought to quantitate the contribution of hospital influence on individual surgeons' transfusion practices.

METHODS

Blood transfusion data for coronary artery bypass graft operations at 12 Providence Health & Services facilities between January 2008 and June 2011 were reviewed. Frequency of perioperative blood transfusion, amount of transfusion, components transfused, and timing of transfusions were compared. Variation among surgeons at the same institution vs between institutions was computed based on multilevel mixed-effect logistic and linear regression models. Intraclass correlation coefficients were calculated.

RESULTS

A total of 5,744 nonemergency first-time coronary artery bypass graft procedures were performed by 42 not-low volume (n>30 in 2.5 years) surgeons at 12 Providence Health & Services hospitals during the 3.5-year study period. Frequency, amount, timing, and blood component usage were different among facilities but relatively similar for surgeons within a facility. The variance of red blood cell transfusion rate among hospitals (.82) is more than two times that among surgeons practicing within the same hospital (.35). Thus, surgeons contribute 30% to the variation, and 70% of the total variation can be explained by the hospital effect.

CONCLUSIONS

In our multihospital system, the hospital that a surgeon practices at plays a larger role in determining blood utilization than the individual surgeon's preference.

Utilization of blood transfusion among older adults in the United States

BACKGROUND

While there have been epidemiologic studies of blood donors, the characteristics of individuals who receive transfusions have not been well described for the US population.

STUDY DESIGN AND METHODS

Subjects were from the nationally representative Health and Retirement Study whose data were linked to Medicare files from 1991 through 2007 (n = 16,377). A cohort study was conducted to assess the frequency of transfusion in older Americans over time and to describe the characteristics of blood recipients.

RESULTS

Thirty-one percent (95% confidence interval [CI], 30%-33%) of older Americans received at least one transfusion within a 10-year period and 5.8% (95% CI, 5.4%-6.2%) experienced repeated transfusion-related visits within 30 days. The mean number of transfusion-related visits was 2.3 over a 10-year period (95% CI, 2.2-2.4). Older Americans who lived in the South were most likely to receive a transfusion (34%), independent of demographic and health-related factors, while those who lived in the western United States were the least likely (26%). Predictors of transfusion included smoking, low body mass index, and a history of cancer, diabetes mellitus, end-stage renal disease, and heart disease. African-Americans and Mexican-Americans had greater rates of blood utilization than other races and other Hispanics (respectively). There were also differences in transfusion utilization by education, marital status, religion, and alcohol use.

CONCLUSIONS

Transfusion is common in older Americans. Regional variations in blood use are not explained by patient characteristics alone.

Best practice in primary care pathology: review 12

This twelfth best practice review examines four series of common primary care questions in laboratory medicine: (i) antiepileptic drug monitoring; (ii) infectious diarrhoea; (iii) methicillin resistant Staphylococcus aureus; and (iv) brain natriuretic peptide. The review is presented in question–answer format, referenced for each question series. The recommendations represent a précis of guidance found using a standardised literature search of national and international guidance notes, consensus statements, health policy documents and evidence-based medicine reviews, supplemented by MEDLINE EMBASE searches to identify relevant primary research documents. They are not standards but form a guide to be set in the clinical context. Most are consensus rather than evidence-based. They will be updated periodically to take account of new information.

Patient blood management - a new paradigm for transfusion medicine?

The saving of many lives in history has been duly credited to blood transfusions. What is frequently overlooked is the fact that, in light of a wealth of evidence as well as other management options, a therapy deemed suitable yesterday may no longer be the first choice today. Use of blood has not been based upon scientific evaluation of benefits, but mostly on anecdotal experience and a variety of factors are challenging current practice. Blood is a precious resource with an ever limiting supply due to the aging population. Costs have also continually increased due to advances (and complexities) in collection, testing, processing and administration of transfusion, which could make up 5% of the total health service budget. Risks of transfusions remain a major concern, with advances in blood screening and processing shifting the profile from infectious to non‐infectious risks. Most worrying though, is the accumulating literature demonstrating a strong (often dose‐dependent) association between transfusion and adverse outcomes. These include increased length of stay, postoperative infection, morbidity and mortality. To this end, a recent international consensus conference on transfusion outcomes (ICCTO) concluded that there was little evidence to corroborate that blood would improve patients’ outcomes in the vast majority of clinical scenarios in which transfusions are currently routinely considered; more appropriate clinical management options should be adopted and transfusion avoided wherever possible. On the other hand, there are patients for whom the perceived benefits of transfusion are likely to outweigh the potential risks. Consensus guidelines for blood component therapy have been developed to assist clinicians in identifying these patients and most of these guidelines have long advocated more conservative ‘triggers’ for transfusion. However, significant variation in practice and inappropriate transfusions are still prevalent. The ‘blood must always be good philosophy’ continues to permeate clinical practice. An alternative approach, however, is being adopted in an increasing number of centres. Experience in managing Jehovah’s Witness patients has shown that complex care without transfusion is possible and results are comparable with, if not better than those of transfused patients. These experiences and rising awareness of downsides of transfusion helped create what has become known as ‘patient blood management’. Principles of this approach include optimizing erythropoiesis, reducing surgical blood loss and harnessing the patient’s physiological tolerance of anaemia. Treatment is tailored to the individual patient, using a multidisciplinary team approach and employing a combination of modalities. Results have demonstrated reduction of transfusion, improved patient outcomes and patient satisfaction. Significant healthcare cost savings have also followed. Despite the success of patient blood management programmes and calls for practice change, the potential and actual harm to patients caused through inappropriate transfusion is still not sufficiently tangible for the public and many clinicians. This has to change. The medical, ethical, legal and economic evidence cannot be ignored. Patient blood management needs to be implemented as the standard of care for all patients.

Prognostic impact of blood transfusion after primary angioplasty for acute myocardial infarction: analysis from the CADILLAC (Controlled Abciximab and Device Investigation to Lower Late Angioplasty Complications) Trial

OBJECTIVES

We sought to determine the relationship between red blood cell (RBC) transfusion and clinical outcomes in patients undergoing primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI).

BACKGROUND

The implications of RBC transfusion in patients undergoing primary PCI for AMI have not been evaluated.

METHODS

Clinical outcomes of patients from the prospective, randomized CADILLAC (Controlled Abciximab and Device Investigation to Lower Late Angioplasty Complications) trial were analyzed by administration of in-hospital RBC transfusion not related to coronary artery bypass surgery.

RESULTS

Of 2,060 randomized patients, 82 (3.98%) received RBC transfusion during the index hospitalization, including 33 (1.60%) with moderate/severe bleeding and 49 (2.38%) without overt major bleeding. Transfusion was independently associated with baseline anemia (odds ratio [95% confidence interval]: 4.44 [2.60 to 7.58], p < 0.0001), older age (1.03 [1.01 to 1.06], p = 0.002), triple-vessel disease (2.54 [1.47 to 4.38], p = 0.0008), and female sex (1.04 [1.02 to 1.06], p = 0.0008). Patients transfused versus not transfused had significantly higher rates of 1-year mortality (23.9% vs. 3.4%), disabling stroke (2.5% vs. 0.5%), reinfarction (7.0% vs. 2.2%), and composite major adverse cardiac events (41.0% vs. 16.6%) (all p values < 0.01). After multivariable adjustment for potential confounders including transfusion propensity, RBC transfusion was independently associated with mortality at 30 days (hazards ratio: 4.71, p = 0.0005) and 1 year (hazards ratio: 3.16, p = 0.0005).

CONCLUSIONS

An RBC transfusion after primary PCI in AMI may be harmful, which is consistent with the findings from other studies after PCI in the noninfarct setting. Alternatively, RBC transfusion may be a marker of markedly increased risk. Randomized studies are warranted to determine the optimal threshold for RBC transfusion in patients with AMI undergoing mechanical reperfusion therapy.

Major bleeding: management and risk reduction in acute coronary syndromes

BACKGROUND

Guidelines for the management of high-risk non ST-segment elevation acute coronary syndrome (NSTE ACS) recommend antithrombotic and antiplatelet therapy combined with an early invasive strategy. While this strategy reduces ischemic complications, it places patients at risk for bleeding complications.

OBJECTIVE

We sought to provide a narrative review of the risk factors for bleeding, risks associated with bleeding and strategies to prevent bleeding complications.

METHODS

A comprehensive literature review was performed to identify relevant evidence.

RESULTS/CONCLUSIONS

Bleeding complications in NSTE ACS are associated with adverse events and higher mortality. Prevention of bleeding complications can be achieved through judicious dosing of medications, the use of antithrombotic agents associated with a lower bleeding risk and use of the radial artery approach in patients requiring coronary intervention. Future work should focus on delineating the mechanisms underlying the bleeding-mortality relationship and developing a better understanding of the tradeoff between efficacy and safety.

Transfusion associated microchimerism: a heretofore little-recognized complication following transfusion

Potent antiplatelet and antithrombotic agents have significantly reduced mortality in the setting of acute coronary syndromes and percutaneous coronary intervention. However these agents are associated with increased bleeding which is in turn associated with adverse clinical outcomes. In many centers, transfusion is often used to correct for blood loss. Blood transfusion in the setting of acute coronary syndrome has been associated with adverse clinical outcomes including increased mortality. Transfusion associated microchimerism (TA-MC) is a newly recognized complication of blood transfusion. There is engraftment of the donor's hematopoietic stem cells in patients who then develop microchimerism. This article discusses the association of bleeding/blood transfusion with adverse outcomes and the potential role of TA-MC in clinical outcomes.

The risk of iatrogenic bleeding in acute coronary syndromes and long-term mortality

PURPOSE OF REVIEW

This review examines the association between bleeding and adverse outcomes in patients with acute coronary syndrome and explores mechanisms behind this association and strategies for reducing bleeding complications in acute coronary syndrome.

RECENT FINDINGS

Bleeding is a common complication of antithrombotic treatment in acute coronary syndrome, and major bleeding occurs in around 5% of patients. Important risk factors for major bleeding include increasing age, female sex, renal impairment, and invasive procedures. Recent studies suggest that major bleeding in patients with acute coronary syndrome is independently associated with an increase of early and long-term morbidity and mortality. This may be due to the direct effects of anaemia and hypovolaemia, the treatment modification or withdrawal, or the adverse effects of transfusion. Bleeding complications may be reduced by use of new antithrombotic agents and by improved attention to dosing with current agents.

SUMMARY

Future studies should examine the effects on overall morbidity and mortality of strategies designed to reduce bleeding complications in patients with acute coronary syndrome. There is a need to apply uniform definitions of bleeding severity. Future trials should report all clinically relevant bleeding outcomes and transfusions. Studies are needed to investigate methods to reduce the risk of bleeding, better understand mechanisms of adverse outcome after bleeding, and establish best practice for the management of bleeding including appropriate use of transfusion in patients with acute coronary syndrome.