The Effect of Preoperative Anemia on the Outcome After Coronary Surgery

Perioperative Red Blood Cell Transfusion and Long-Term Mortality in Coronary Artery Bypass Grafting: On-Pump and Off-Pump Analysis

Background/Objectives: The impact of different coronary artery bypass grafting (CABG) strategies, particularly on-pump versus off-pump techniques, on red blood cell (RBC) transfusions and their associated outcomes has not been fully investigated. This study aims to evaluate the association between RBC transfusion and survival in CABG patients, focusing on-pump strategy. Methods: Data from CABG patients were retrieved from the National Health Insurance Service database (2003 to 2019). Perioperative RBC transfusions were classified into three groups: no transfusion, RBC 1, and RBC ≥ 2 units. The primary endpoint was all-cause mortality rate. Subgroup analysis assessed the impact of RBC transfusion on mortality across the conventional on-pump (CCAB) and off-pump (OPCAB) groups. Results: Among the 6150 participants who underwent CABG, 2028 underwent CCAB and 4122 underwent OPCAB. The mean age was 66.2 ± 9.7 years, with a mean follow-up of 2.9 (2.53-3.35) years. Multivariable analysis showed a significant association between transfusion of ≥2 RBC units and increased mortality risk (HR 2.34 [1.65-3.32], p < 0.001). Subgroup analysis showed a similar trend in both CCAB and OPCAB groups (p for interaction = 0.2). Transfusion of ≥2 units significantly increased mortality in OPCAB (HR 2.28 [1.55-3.37], p < 0.001) but not in CCAB (HR 2.96 [0.97-9.06], p = 0.057). OPCAB and surgery at large volume center was associated with a reduced risk of RBC transfusion (p < 0.01). Conclusions: Increased RBC transfusion is associated with higher long-term mortality in patients undergoing CABG. Based on a large cohort predominantly consisting of OPCAB patients, OPCAB is associated with decreased RBC transfusion requirements.

Implementing a Preoperative Anemia Optimization Protocol for Cardiovascular Surgery Patients: A Quality Improvement Project

BACKGROUND

Patients with anemia have poorer outcomes following cardiac surgery than do those without anemia. To improve outcomes, the Enhanced Recovery After Surgery cardiac recommendations include optimizing patients' condition, including treating anemia, before surgery.

LOCAL PROBLEM

Despite implementing Enhanced Recovery After Surgery initiatives, a midwestern cardiothoracic surgery group recognized a care gap in preoperative patients with anemia. No standardized protocol was in use.

METHODS

An anemia optimization protocol was developed for perioperative care of patients with anemia. Data from retrospective medical record review were analyzed to determine relationships between protocol use and secondary outcomes. The protocol was created using best evidence and expert consensus. Cardiac surgery and hematology specialists revised the protocol and agreed on a final version. The protocol was integrated into the consultation process for cardiac surgery patients.

RESULTS

During the implementation period, 23 of 55 patients with anemia (42%) received interventions via the anemia optimization protocol. The mean quantity of packed red blood cells transfused perioperatively per patient was 1.9 U in the protocol group and 3.5 U in the nonprotocol group. In the subgroup of patients experiencing postoperative acute kidney injury, the mean increase in creatinine level was 0.65 mg/dL in the protocol group and 1.52 mg/dL in the nonprotocol group. Four patients in the protocol group (17%) and 6 patients in the nonprotocol group (19%) experienced postoperative acute kidney injury.

CONCLUSION

Preoperative anemia is associated with poorer cardiac surgical outcomes. Incorporating the anemia optimization protocol into practice may mitigate the risk of postoperative complications for patients with anemia. Continued use of the protocol is recommended.

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

BACKGROUND

This study characterized the association of preoperative anemia and intraoperative red blood cell (RBC) transfusion on outcomes of elective coronary artery bypass grafting (CABG).

METHODS

Data from 53,856 patients who underwent CABG included in The Society of Thoracic Surgeons (STS) Adult Cardiac Database in 2019 were used. The primary outcome was operative mortality. Secondary outcomes were postoperative complications. The association of anemia with outcomes was analyzed with multivariable regression models. The influence of intraoperative RBC transfusion on the effect of preoperative anemia on outcomes was studied using mediation analysis.

RESULTS

Anemia was present in 25% of patients. Anemic patients had a higher STS Predicted Risk of Operative Mortality (1.2% vs 0.7%; P < .001). Anemia was associated with operative mortality (odds ratio [OR], 1.27; 99.5% CI, 1.00-1.61; P = .047), postoperative RBC transfusion (OR, 2.28; 99.5% CI, 2.12-2.44; P < .001), dialysis (OR, 1.58; 99.5% CI, 1.19-2.11; P < .001), and prolonged intensive care unit and hospital length of stay. Intraoperative RBC transfusion largely mediated the effects of anemia on mortality (76%), intensive care unit stay (99%), and hospital stay, but it only partially mediated the association with dialysis (34.9%).

CONCLUSIONS

Preoperative anemia is common in patients who undergo CABG and is associated with increased postoperative risks of mortality, complications, and RBC transfusion. However, most of the effect of anemia on mortality is mediated through intraoperative RBC transfusion.

Preoperative anemia and anemia treatment in cardiac surgery: a systematic review and meta-analysis

PURPOSE

We aimed to conduct a systematic review and meta-analysis to assess the effects of anemia and anemia severity on patient outcomes in cardiac surgery and determine whether preoperative treatments confer postoperative benefit.

SOURCE

We searched four international databases for observational and randomized studies published until 1 October 2022. Study quality was assessed via Newcastle-Ottawa scores and the Cochrane Risk-of-Bias 2 tool and certainty of evidence was rated with the Grading of Recommendations, Assessment, Development and Evaluations approach. We conducted random-effects meta-analyses for our primary outcome of mortality, for secondary outcomes including length of stay (LOS) in the hospital and intensive care unit, and for postsurgical complications. As part of a secondary analysis, we analyzed short-term preoperative anemia treatments and conducted trial sequential analysis of randomized trials to assess the efficacy of these treatment programs.

PRINCIPAL FINDINGS

We included 35 studies (159,025 patients) in our primary meta-analysis. Preoperative anemia was associated with increased mortality (odds ratio [OR], 2.5; 95% confidence interval [CI], 2.2 to 2.9; P < 0.001, high certainty). Study-level meta-regression revealed lower hemoglobin levels and studies with lower proportions of male patients to be associated with increased risk of mortality. Preoperative anemia was also associated with an increase in LOS and postsurgical complications. Our secondary analysis (seven studies, 1,012 patients) revealed short-term preoperative anemia treatments did not significantly reduce mortality (OR, 1.1; 95% CI, 0.65 to 1.9; P = 0.69). Trial sequential analysis suggested that there was insufficient evidence to conclude if treatment programs yield any benefit or harm.

CONCLUSIONS

Preoperative anemia is associated with mortality and morbidity after cardiac surgery. More research is warranted to test the efficacy of current anemia treatment programs.

STUDY REGISTRATION

PROSPERO (CRD42022319431); first submitted 17 April 2023.

The association between preoperative anemia, blood transfusion need, and postoperative complications in adult cardiac surgery, a single center contemporary experience

BACKGROUND

The impact of preoperative anemia on postcardiac surgery outcomes is an area of great debate. Although several large-scale studies have been conducted, they have demonstrated conflicting results. A limited number of studies have been conducted in the Middle East. The primary aim of this study was to investigate the association between preoperative anemia and the need for blood transfusions, as well as major postoperative complications.

METHODS

Adult patients who underwent cardiac surgery at King Faisal Cardiac Center in Jeddah between June 2016 and January 2020 were included in this retrospective cohort study. The study excluded patients with hereditary preoperative anemia. Among the variables studied were variables related to demographics, comorbidities, laboratory data, operation-related data, in-hospital complications, and mortality.

RESULTS

The mean preoperative hemoglobin (Hb) level was 13.2 g/dL (SD ± 1.8). The overall mortality rate was 4.6%. A lower preoperative Hb level (p value = 0.016), postoperative day 1 WBC count (p-value = 0.003), and prolonged cross clamp time (p value < 0.001) were significantly associated with mortality. A lower Hb level during the preoperative period or within the first three days of surgery was associated with a higher blood transfusion requirement. However, there was no significant association between blood transfusion and postoperative complications. A multivariate stepwise logistic regression model was developed and several pre and intra operative factors were predictive of the need PRBCs transfusion after cardiac surgery (which included: older age, female gender, lower pre-operative hemoglobin and longer cardio-pulmonary bypass time), with had a predictive accuracy of around ~ 86%.

CONCLUSION

Based on our single center study, patients with preoperative lower Hb levels are at higher risk of mortality. However, blood transfusion does not seem to increase the risk of postoperative complications. Optimal utilization of blood products is an important quality metric and identification of patients at higher risk of requiring PRBCs transfusion prior to cardiac surgery can help in implementing pre or intra operative strategies to minimize the need for transfusion.

Total arterial coronary artery bypass grafting in patients with preoperative anemia

OBJECTIVES

Blood transfusions after coronary artery bypass grafting (CABG) has been associated to adverse outcomes, especially in anemic patients. However, little is known about the influence of the modality of revascularization. Total arterial revascularization (TAR) was shown to reduce postoperative transfusion when compared to saphenous vein-based (SV)-CABG (LIMA plus one/more SV grafts). We, therefore, aimed to investigate the impact of TAR-CABG versus SV-CABG on blood products use and perioperative outcomes in patients with preoperative anemia, normally at higher risk for postoperative transfusions.

METHODS

From a cohort of 936 patients with mild preoperative anemia undergoing primary elective on-pump CABG, 166 matched pairs of patients undergoing either TAR- or SV-CABG were obtained. Anemia was defined as hemoglobin level <13 g/dl for men and <12 g/dl for women. The primary endpoint was the evaluation of red packed cells (RPC) use over the entire hospital stay.

RESULTS

TAR patients showed significantly reduced RPC usage compared with SV (mean difference 0.45 units). TAR patients had a reduced intubation time (mean difference 7.6 h) and were discharged 1.24 days earlier than SV patients. Pneumonia and acute kidney injury were doubled among SV patients. Adjusted regression showed that TAR technique is a predictor of reduced RPC unit use regardless of age and EuroSCORE II (odds ratio: 0.63, p < .01).

CONCLUSION

Patients with preoperative anemia might benefit from TAR regardless of age or calculated operative risk. TAR-CABG was associated to reduced postoperative use of blood products and postoperative length of stay in comparison with SV-CABG in this subset of patients.

Preoperative Anemia is Associated with Increased Intraoperative Mortality in Patients Undergoing Cardiac Surgery

Objectives

We sought to investigate the incidence of preoperative anemia in cardiac surgery and its association with outcomes.

Methods

A retrospective review of clinical, laboratory, and transfusion data for all patients who underwent cardiac surgery at Sultan Qaboos University Hospital between 2008 and 2014 was performed. Patients were divided into two groups, anemic and non-anemic, with anemia defined as hemoglobin levels < 13 g/dL (males) and < 12 g/dL (females). Clinical variables were compared using chi-square and independent t-test. Factors influencing preoperative mortality were analyzed using multivariate binary logistics regression.

Results

A total of 599 patients (69.9% males and 30.1% females) were included in the study; 69.3% underwent coronary artery bypass surgery. Preoperative anemia was found in 76.1% of females and 26.7% of male patients. Rates of intraoperative red blood cell transfusions were higher among anemic patients (75.9% vs. 52.3%, p < 0.001). Anemic patients had a worse risk profile with higher incidence of diabetes mellitus (53.8% vs. 38.9%, p < 0.001), congestive heart failure (51.4% vs. 28.3%, p < 0.001), arrhythmia (16.5% vs. 8.6%, p = 0.004), and cerebrovascular disease (10.0% vs. 4.9%, p = 0.015). In addition, they had a higher risk of overall mortality (6.4% vs. 2.6%, p = 0.023). Preoperative anemia remained a risk factor for intraoperative mortality after logistic regression (odds ratio = 4.08, 95% confidence interval: 1.43–11.66; p = 0.009).

Conclusions

Preoperative anemia in cardiac surgery is independently associated with increased intraoperative mortality and early readmission rates post-surgery.

Preoperative Anemia as a Risk Factor for Postoperative Outcomes in Patients Undergoing Lung Transplantation

OBJECTIVES

The aim of this study was to evaluate the effect of preoperative anemia on early postoperative outcomes in a population of patients undergoing lung transplantation.

DESIGN

Single-center retrospective study of lung transplantation recipients between April 2013 and June 2018. The primary outcome was hospital length of stay.

SETTING

Ronald Reagan UCLA Medical Center, Los Angeles, CA, a tertiary academic medical center.

PARTICIPANTS

Patients presenting from home for lung transplantation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A total of 435 patients underwent lung transplantation during the study period. After exclusion, 342 were included in the analysis. The prevalence of preoperative anemia was 54% (n = 183); however, only 11% of anemic patients received treatment for anemia before transplantation. Multivariate regression analysis indicated that lower hemoglobin levels were associated with longer hospital lengths of stay (p = 0.049). Preoperative anemia also was independently associated with an increased risk for redo surgery for bleeding (odds ratio 4.89; p = 0.007). No association between preoperative anemia and any of the other postoperative outcomes examined was found.

CONCLUSIONS

Preoperative anemia in patients undergoing lung transplantation is undertreated and independently associated with an increased risk for redo surgery for bleeding. Additional studies regarding reasons for this association and effect of treatment are necessary to improve outcomes.

Anemia and perioperative mortality in non-cardiac surgery patients: a secondary analysis based on a single-center retrospective study

Background

Evidence regarding the relationship between anemia and perioperative prognosis is controversial. The study was conducted to highlight the specific relationship between anemia and perioperative mortality in non-cardiac surgery patients over 18 years of age.

Methods

This study was a retrospective analysis of the electronic medical records of 90,784 patients at the Singapore General Hospital from January 1, 2012 to October 31, 2016. Multivariate regression, propensity score analysis, doubly robust estimation, and an inverse probability-weighting model was used to ensure the robustness of our findings.

Results

We identified 85,989 patients, of whom75, 163 had none or mild anemia (Hemoglobin>90g/L) and 10,826 had moderate or severe anemia (Hemoglobin≤90g/L). 8,857 patients in each study exposure group had similar propensity scores and were included in the analyses. In the doubly robust model, postoperative 30-day mortality rate was increased by 0.51% (n = 219) in moderate or severe anemia group (Odds Ratio, 1.510; 95% Confidence Interval (CI), 1.049 to 2.174) compared with none or mild anemia group (2.47% vs.1.22%, P<0.001). Moderate or severe anemia was also associated with increased postoperative blood transfusion rates (OR, 5.608; 95% CI, 4.026 to 7.811, P < 0.001). There was no statistical difference in Intensive Care Unit (ICU) admission rate among different anemia groups within 30 days after surgery (P=0.104).

Discussion

In patients undergoing non-cardiac surgery over 18 years old, moderate or severe preoperative anemia would increase the occurrence of postoperative blood transfusion and the risk of death, rather than ICU admission within 30 days after surgery.

The Effect of Preoperative Hematocrit Level on Early Outcomes After Coronary Artery Bypass Surgery

INTRODUCTION

Low hematocrit level is a hematological problem that is frequently encountered in the preoperative evaluation of patients undergoing coronary artery bypass grafting (CABG) surgery. The aim of this study was to investigate the effect of preoperative hematocrit level on the first 30-day outcomes in patients undergoing CABG surgery.

METHODS

Ninety-four patients undergoing isolated CABG were included in the study. The patients were divided into two groups as patients with preoperative low hematocrit levels (<36%) in Group 1 and patients with preoperative normal hematocrit levels (≥36%) in Group 2.

RESULTS

Forty-six patients in Group 1 (mean age: 63.6 ± 7.9 years) and 48 patients in Group 2 (mean age: 56.5 ± 8.8 years) were enrolled. European System for Cardiac Operative Risk Evaluation (EuroSCORE) scoring was statistically significantly higher in Group 1 (p = 0.011). In the postoperative period, the amount of drainage, transfusion of blood, and blood products were significantly higher in Group 1 (p < 0.001). The mortality rate of Group 1 was statistically higher in the first 30 days postoperatively (p = 0.020).

CONCLUSION

Low preoperative hematocrit levels are associated with increased mortality after CABG surgery. We suggest that patients' preoperative hematocrit levels must be added to the risk scoring systems as an assessment parameter.

Association of Preoperative Anemia With 30-Day Morbidity and Mortality Among Patients With Thyroid Cancer Who Undergo Thyroidectomy

Importance

Despite the ease of preoperative anemia diagnosis and the availability of treatment options, the morbidity and mortality associated with this condition remain unacceptably high, and the literature describing the association of preoperative anemia with postoperative outcomes following thyroid surgery in patients with thyroid cancer remain sparse. Reporting outcomes in this patient population may help to facilitate preoperative optimization.

Objective

To assess whether an association exists between preoperative anemia and outcomes following thyroid surgery in patients with thyroid cancer.

Design, Setting, and Participants

This retrospective, cross-sectional, cohort study used the American College of Surgeons National Surgical Quality Improvement Program database to identify 32 166 patients between 2007 and 2016 with Current Procedural Terminology codes for thyroid surgery and with the International Classification of Diseases, Ninth Revision code of malignant thyroid cancer.

Exposures

Preoperative anemia as defined using the World Health Organization criteria of hematocrit less than 36% in nonpregnant females and less than 39% in males.

Main Outcomes and Measures

Multivariable logistic regression analysis was conducted to assess the association of preoperative anemia with the following 30-day postoperative outcomes: pulmonary, infectious, and cardiac complications, overall and serious morbidity (surgical site infection and medical complications), prolonged hospital length of stay (≥75th percentile for the cohort), and mortality.

Results

Among the 24 912 patients with thyroid cancer who underwent thyroidectomy included in the final analysis, the median (interquartile range) age was 51 (40-62) years and the majority were women (18 705 [75.1%]). The prevalence of preoperative anemia was 12.5% (n = 3108). Within the overall study population, hypertension (9242 patients [37.1%]) followed by active smoking (2992 patients [12.0%]) were the most prevalent comorbidities. The unadjusted odds of anemia vs no anemia were significantly higher for every 10-year increase in age (odds ratio [OR], 1.10; 95% CI, 1.08-1.13) and for black vs white patients (OR, 2.82; 95% CI, 2.51-3.17). The adjusted odds of postoperative overall morbidity (OR, 1.68; 95% CI, 1.29-2.17), mortality (OR, 3.36; 95% CI, 1.37-8.28), and pulmonary (OR, 2.36; 95% CI, 1.65-3.34) and infectious (OR, 1.62; 95% CI, 1.12-2.29) complications were higher in patients with preoperative anemia than in those without preoperative anemia.

Conclusions and Relevance

The findings from this study suggest that preoperative anemia may not only be associated with racial differences and a higher comorbidity burden but may also increase the likelihood of postoperative morbidity and mortality. These results may provide a basis for further risk reduction strategies and preoperative optimization.

Anaemia in patients who underwent vascular surgery: a significant predictor of amputation and death

BACKGROUND AND OBJECTIVE

In patients with peripheral artery disease requiring surgery, anaemia has been found to independently predict short and medium term higher morbidity and mortality.

PATIENTS AND METHODS

We retrospectively studied all patients undergoing surgery, consecutively during 2months in 12 vascular surgery units. We analysed cardiovascular risk factors and preoperative haemoglobin. Statistical analysis was done with Kaplan-Meier for survival and logistic regression modelling to identify predictors of mortality.

RESULTS

518 patients were consecutively operated on in our vascular units, the mortality rate was 21% the first year and 34% for cardiovascular events. Preoperative anaemia was present in 63% of the ischemic patients and in 23% of the patients requiring aneurysm repair, one year after surgery it increased to 68% and 50% respectively. When preoperative anaemia was superior to 10mg/dl, one year survival increased (96% vs. 90%), fewer cardiovascular events occurred and there were fewer amputations (24% vs. 68%).

CONCLUSIONS

On multivariable analysis: age, renal failure, chronic lung disease, coronary artery disease, postoperative complications and previous cardiovascular events were associated with an increased risk mortality rate. Preoperative haemoglobin influenced proportionally such that for every 1mg /dl increase, the probability of mortality decreases by 0.81. Preoperative anaemia, especially when haemoglobin is inferior to 10mg/dl, is associated with an increased risk of death and amputation.