Anemia Increases Mortality After Open or Endovascular Treatment in Patients with Critical Limb Ischemia: A Retrospective Analysis

Impact of Preoperative Anemia on Hospitalization, Death, and Overall Survival in Patients With Peripheral Artery Disease Undergoing Endovascular Therapy: A Retrospective Cohort Study in the United States and Canada

PURPOSE

Preoperative anemia is associated with adverse outcomes after cardiac and noncardiac surgeries, but outcomes after an endovascular peripheral vascular intervention (PVI) are not well established. We aimed to assess the association of preoperative anemia with 30 day death, hospital length of stay (LOS), and overall (long term) survival in patients undergoing an endovascular PVI for peripheral artery disease.

MATERIALS AND METHODS

In this retrospective, cohort study in the United States and Canada, we queried the national Vascular Quality Initiative database for all endovascular PVIs performed between 2010 and 2019, and outcomes were correlated with patients' hemoglobin (Hb) levels. Anemia was classified as mild (Hb=10-13 g/dL for men and 10-12 g/dL for women), moderate (Hb=8-9.9 g/dL), and severe (Hb<8 g/dL).

RESULTS

A total of 79 707 adult patients who met study criteria underwent endovascular PVI. The mean age was 68 years, and 59% of patients were male. Anemia was documented in 38 543 patients (48%) and was mild in 27 435 (71%), moderate in 9783 (25%), and severe in 1325 (4%). The median follow-up duration was 4 years (range, 1.25-5.78 years). On univariate analysis, 30 day mortality, total LOS, and overall survival were significantly associated with the level of preoperative anemia. These associations persisted in the multivariate models. Kaplan-Meier survival analysis demonstrated an association of death with degree of anemia (p<0.001).

CONCLUSION

The presence and degree of preoperative anemia were independently associated with increased 30 day mortality and LOS and decreased overall survival for patients with peripheral artery disease who had undergone endovascular PVI.

CLINICAL IMPACT

The findings from this study have many implications for how to approach vascular surgery in patients with variable hemoglobin levels. Our findings will strengthen our ability to conduct accurate preoperative risk stratification for patients undergoing peripheral vascular interventions. This may also mitigate healthcare expenditures if findings are applied in a way that can lower patient length of postoperative stay while also maintaining quality of care and patient safety. Our results will also serve as guidance for clinical trials, and future prospective trials should evaluate the effect of preoperative optimization of hemoglobin as a potentially modifiable risk factor for outcomes.

Impact of Chronic Kidney Disease on In-Hospital Outcomes of Hospitalizations With Acute Limb Ischemia Undergoing Endovascular Therapy

PURPOSE

Studies on outcomes related to endovascular treatment (EVT) in advanced stages of chronic kidney disease (CKD) and end-stage renal disease (ESRD) among hospitalizations with acute limb ischemia (ALI) are limited.

METHODS

The Nationwide Inpatient Sample was quarried from October 2015 to December 2017 to identify the hospitalizations with ALI and undergoing EVT. The study population was subdivided into 3 groups based on their CKD stages: group 1 (No CKD, stage I, stage II), group 2 (CKD stage III, stage IV), and group 3 (CKD stage V and ESRD). The primary outcome was all-cause in-hospital mortality.

RESULTS

A total of 51 995 hospitalizations with ALI undergoing EVT were identified. The in-hospital mortality was significantly higher in group 2 (OR = 1.17; 95% CI 1.04 - 1.32, p=0.009) and group 3 (OR = 3.18; 95% CI 2.74-3.69, p<0.0001) compared with group 1. Odds of minor amputation, vascular complication, atherectomy, and blood transfusion were higher among groups 2 and 3 compared with group 1. Group 2 had higher odds of access site hemorrhage compared with groups 1 and 3, whereas group 3 had higher odds of major amputation, postprocedural infection, and postoperative hemorrhage compared with groups 1 and 2. Besides, groups 2 and 3 had lower odds of discharge to home compared with group 1. Finally, the length of hospital stay and cost of care was significantly higher with the advancing CKD stages.

CONCLUSION

Advanced CKD stages and ESRD are associated with higher mortality, worse in-hospital outcomes and higher resource utilization among ALI hospitalizations undergoing EVT.

CLINICAL IMPACT

Current guidelines are not clear for the optimum first line treatment of acute limb ischemia, especially in patients with advanced kidney disease as compared to normal/mild kidney disease patients. We found that advanced kidney disease is a significant risk factor for worse in-hospital morbidity and mortality. Furthermore, patients with acute limb ischemia and advanced kidney disease is associated with significantly higher resource utilization as compared to patients with normal/mild kidney disease. This study suggests shared decision making between treating physician and patients when considering endovascular therapy for the treatment of acute limb ischemia in patients with advanced kidney disease.

High Mortality in Patients With an Ischemic Foot Ulcer Following Revascularization

Critical limb ischemia (CLI) is the advanced stage of peripheral arterial disease, which impairs blood flow to the extremities due to occlusion of arteries, in which patients suffer from ischemic pain at rest and gangrene or ulcers. It is frequently accompanied by major adverse cardiac events, resulting in exceedingly high mortality from a cardiac or cerebrovascular event in this population. Although there have been considerable amounts of novel and costly revascularization and wound dressing technology, mortality is still high. Therefore, the risk factors for such high mortality need to be addressed. This review aimed to summarize the potential risk factors for mortality in patients with CLI of the lower extremities. There are several such risk factors, including modifiable and nonmodifiable risk factors. This review further discusses some highlighted major modified risk factors, including renal failure, cardiovascular, and diabetes. The strategy of regular surveillance and modification of such risk factors in any patients with CLI should be developed.

Association between High Bleeding Risk and 2-Year Mortality in Patients with Chronic Limb-Threatening Ischemia

AIM

Patients with chronic limb-threatening ischemia (CLTI) have a high bleeding risk (HBR) and mortality rate. The 2-year life expectancy is an important factor in deciding the appropriate treatment strategy. This study aimed to assess the influence of HBR on the prognosis of patients with CLTI.

METHODS

A total of 259 patients with CLTI who underwent endovascular therapy (EVT) (mean age, 76.2 years; male, 62.9%) between January 2018 and December 2019 were evaluated. The Academic Research Consortium for HBR (ARC-HBR) criteria were applied to each patient, and the ARC-HBR scores were calculated. The cut-off score for predicting all-cause mortality within two years was derived using a survival classification and regression tree (CART) model. Causes of death and the association between ARC-HBR scores and major bleeding events within two years were also investigated.

RESULTS

Based on the CART model, patients were divided into three groups (low HBR score 0-1.0, 48 patients; moderate HBR score 1.5-3.0, 176 patients; and high HBR score ≥ 3.5, 35 patients). During the study period, 82 patients (39.6%) died due to cardiac (n=23) and non-cardiac causes (n=59). All-cause mortality increased significantly with increasing ARC-HBR scores. Cox multivariate analysis revealed a significant association between high ARC-HBR scores and the risk of all-cause mortality within two years. Major bleeding events increased significantly with increasing ARC-HBR scores.

CONCLUSIONS

The ARC-HBR score could predict 2-year mortality in patients with CLTI who underwent EVT. Thus, this score can help determine the best revascularization strategy for patients with CLTI.

Anemia as a risk factor for restenosis in femoropopliteal arterial disease after drug-coated balloon angioplasty

OBJECTIVE

This study aimed to investigate the relationship between anemia and restenosis in patients with femoropopliteal arterial disease following drug-coated balloon (DCB) angioplasty.

METHODS

194 patients treated with DCB for femoropopliteal lesions were retrospectively analyzed for up to 12 months of follow-up between January 2017 and September 2020. Baseline clinical and procedural characteristics were compared between the anemia and non-anemia patients, and predictors of restenosis were identified using logistic regression.

RESULTS

32.5% of the patients undergoing DCB angioplasty had anemia. Patients with anemia were significantly older, with higher rates of hypertension, coronary artery disease, chronic renal insufficiency, and diabetes, and with lower rates of smoking and male gender. In the multivariate analysis, anemia was independently and significantly associated with a higher risk of restenosis (OR, 3.872; 95% CI, 1.556-9.638; P = 0.004).

CONCLUSION

Anemia is independently associated with restenosis in patients treated with DCB for femoropopliteal arterial disease. Patients with lower baseline hemoglobin might have more chances to develop restenosis at follow-up.

The Impact of Pre-Operative Anaemia on One Year Amputation Free Survival and Re-Admissions in Patients Undergoing Vascular Surgery for Peripheral Arterial Disease: a National Vascular Registry Study

OBJECTIVE

Anaemia is common among patients undergoing surgery, but its association with post-operative outcomes in patients with peripheral arterial disease (PAD) is unclear. The aim of this observational population based study was to examine the association between pre-operative anaemia and one year outcomes after surgical revascularisation for PAD.

METHODS

This study used data from the National Vascular Registry, linked with an administrative database (Hospital Episode Statistics), to identify patients who underwent open surgical lower limb revascularisation for PAD in English NHS hospitals between January 2016 and December 2019. The primary outcome was one year amputation free survival. Secondary outcomes were one year re-admission rate, 30 day re-intervention rate, 30 day ipsilateral major amputation rate and 30 day death. Flexible parametric survival analysis and generalised linear regression were performed to assess the effect of anaemia on one year outcomes.

RESULTS

The analysis included 13 641 patients, 57.9% of whom had no anaemia, 23.8% mild, and 18.3% moderate or severe anaemia. At one year follow up, 80.6% of patients were alive and amputation free. The risk of one year amputation or death was elevated in patients with mild anaemia (adjusted HR 1.3; 95% CI 1.15 - 1.41) and moderate or severe anaemia (aHR 1.5; 1.33 - 1.67). Patients with moderate or severe anaemia experienced more re-admissions over one year (adjusted IRR 1.31; 1.26 - 1.37) and had higher odds of 30 day re-interventions (aOR 1.22; 1.04 - 1.45), 30 day ipsilateral major amputation (aOR 1.53; 1.17 - 2.01), and 30 day death (aOR 1.39; 1.03 - 1.88) compared with patients with no anaemia.

CONCLUSION

Pre-operative anaemia is associated with lower one year amputation free survival and higher one year re-admission rates following surgical revascularisation in patients with PAD. Research is required to evaluate whether interventions to correct anaemia improve outcomes after lower limb revascularisation.

Use of the 11-Item Modified Frailty Index to Determine Accurate Prognosis and Revascularization Strategy in Patients Undergoing Vascular Bypass Surgery for Intermittent Claudication

BACKGROUND

In cases of intermittent claudication (IC) where traditionally noninvasive management yields unsatisfactory results, revascularization strategy in IC patients is generally decided based on anatomical considerations and the availability of a saphenous vein graft. Life expectancy should also be considered. This study aimed to investigate the relationship between the 11-item modified frailty index (mFI-11) and the overall survival (OS) in patients with IC who underwent vascular bypass surgery to facilitate revascularization strategy selection.

METHODS

We reviewed the records of 144 consecutive patients (153 lower limbs) who underwent infrainguinal bypass for IC between 2011 and 2020. Patients were divided into 2 groups based on their mFI-11 score: high frailty (H), mFI score >0.3; and low frailty (L), mFI score ≤0.3. The OS was compared among the 2 groups. Rates of graft patency and freedom from major adverse limb event (ffMALE) were also determined and compared.

RESULTS

Five-year OS in the L and H groups was 92% and 55% (P < 0.001). Multivariate analysis showed that mFI, age, and end-stage renal disease were independent predictors of OS. Five-year rates of primary and secondary patency and ffMALE for vein grafts were 81%, 91%, and 94%, respectively; those for prosthetic grafts were 65%, 80%, and 84%, respectively; the differences were not significant.

CONCLUSIONS

The mFI-11 was a helpful tool in predicting OS for patients with IC who underwent vascular bypass surgery. Those with H should not undergo open revascularization; however, for IC patients who have either not responded to a regimen of exercise and medication, or have specifically requested a more aggressive approach, obtaining a good score in frailty assessment is useful in determining whether or not bypass surgery would be a viable option.

Peri-procedural complications following endovascular revascularization for critical limb ischemia

OBJECTIVE

Revascularization procedures are considered the cornerstone of therapy in patients with critical limb ischemia (CLI) and multiple procedures are often required to attain limb salvage. The aim of the present study is to determine the prevalence of peri-procedural complications after endovascular procedure, and to determine the clinical and biological characteristics of patients associated to the risk of peri-procedural complications.

METHODS

From November 2013 to May 2021, 324 consecutive patients were retrospectively included, of whom 99 underwent more than one revascularization procedure for contralateral CLI or clinical recurrence of CLI. A total of 532 revascularizations were performed. Clinical and biological parameters were recorded at baseline before endovascular revascularization. The occurrence of a peri-procedural complication (local complications, fatal and non-fatal major bleeding or cardiovascular events) was recorded up to 30days after revascularization. Univariate and multivariate analyses were performed to study the parameters associated with per-procedural complications. A P<0.05 was considered as statistically significant.

RESULTS

A total of 324 consecutive patients were included, 177 men and 147 women with CLI, with a mean age of 77.6±11.9years. Most of these patients had cardiovascular comorbidities (41% with a history of coronary heart disease, 78% treated hypertensive patients, 49% diabetic patients). Peri-procedural mortality occurred in 13 patients (4%) and 9 patients (2.8%) experienced major amputation at one-month following revascularization. Among the 532 revascularization procedures, 99 major bleeding events (22.8% of the cohort population) and 31 cardiovascular events (8.6% of the cohort population), were recorded in the peri-procedural period. Cardiovascular events were associated with peri-procedural mortality. Complications at the puncture site occurred during 38 of the 532 procedures (10.2% of the cohort population). Compared with patients undergoing a single revascularization procedure, patients with multiple procedures presented a higher risk of major bleeding events (48.5% vs. 11.6%, P<0.0001) and access site complications (20.2% vs. 5.78%, P<0.0001). In multivariate analysis, pulse pressure <60mmHg and hemoglobin level <10g/dl were correlated with the occurrence of major bleeding events; left ventricular ejection fraction<60% and the absence of statin treatment were correlated with the occurrence of cardiovascular complications; a high chronological rank of revascularization was correlated with the occurrence of local complication. Finally, age and gender were not associated with the occurrence of peri-procedural complication.

CONCLUSION

The present results highlight that multiple revascularization procedures for limb salvage are required in almost one third of the population with critical limb ischemia and were associated with the risk of major bleeding events and access site complications. The most frequent complications of peripheral vascular interventions were major bleeding events. Adverse cardiovascular events were related with peri-procedural mortality. Anemia, blood pressure, left ventricular ejection fraction and statin treatment are important parameters to consider for peri-procedural outcomes, independently of age, gender and the chronological rank of revascularization procedure.

The Effect of Smoking Status on Perioperative Morbidity and Mortality after Open and Endovascular Abdominal Aortic Aneurysm Repair

OBJECTIVES

This study quantifies the extent to which active tobacco smoking is deleterious towards outcomes following open and endovascular AAA repair.

METHODS

Open and endovascular abdominal aortic aneurysm (AAA) repairs between January 2003 and June 2020 in the Vascular Quality Initiative (VQI) were queried. Rupture, symptomatic status, and lack of 90 day follow up were exclusions. Patients were then placed into one of six groups : open AAA with active smoking (n=3788); open AAA with prior smoking (n=4614); open AAA never smokers (817); endovascular AAA active smokers (n=14173); endovascular AAA former smokers (n=25,831); and, endovascular AAA never smokers (n=6064). Comparison of baseline characteristics, co-morbidities, and adverse outcomes across each of the 6 cohorts was performed with open AAA in active smokers serving as the reference. Sub-analysis investigating open AAA repair in active smokers relative to open AAA in patients confirmed in VQI to have quit smoking between 30 and 90 days before surgery was performed. Smoking cessation for a minimum of 30 days before surgery was required to fall into the former smoker category.

RESULTS

In comparing open AAA in active smokers to open AAA in former and never smokers, the active smokers experienced significantly higher rates of pneumonia (P<.001). Combined additive morbidity and mortality was highest (54%) in active smokers (P<.001 relative to all cohorts other than open AAA former smokers P=.21). Smoking status did not impact morbidity or mortality incidence across individuals undergoing EVAR. Binary logistic regression for all AAA patients (open and endovascular combined) revealed those with any history of smoking to be more likely to experience 90 day mortality (adjusted OR 2.5 (2.2-2.9), P<.001) relative to never-smokers. Active smokers were similarly more likely to experience 90 day mortality than prior/never smokers combined (OR 1.23 (1.07-1.38), P<.001). Mortality within 90 days was significantly more likely (P<.001) with aging, female gender, larger aneurysms, preoperative history of congestive heart failure, chronic obstructive pulmonary disease, chronic renal insufficiency, peripheral artery disease, body mass index under 20 and over 35 mg/kg². Diabetes and coronary artery disease were also associated with 90 day mortality (P= .045 and .049 respectively). Quitting smoking between 30 and 90 days before open repair reduced combined additive morbidity and mortality relative to active smokers (OR 1.34, P =.038).

CONCLUSIONS

Smoking cessation 30 days before open AAA repair reduces perioperative morbidity and mortality. Smoking status does not impact morbidity and mortality in patients undergoing endovascular AAA repair. When combining all patients (open and endovascular), higher rates of 90 day mortality are associated with any history of smoking, aging, female gender and advanced pre-existing co-morbidities on multivariable analysis.

Factors Affecting Mortality of Critical Limb Ischemia 1 Year after Endovascular Revascularization in Patients with Type 2 Diabetes Mellitus

BACKGROUND

Chronic limb ischemia (CLI) is strongly associated with increased mortality in diabetes patients.

OBJECTIVE

The aim of this study was to evaluate factors affecting mortality within 1 year after endovascular revascularization in CLI patients.

METHODS

This retrospective cohort study was based on medical records from the Integrated Cardiovascular Centre of Dr. Cipto Mangunkusumo National General Hospital, a tertiary care hospital in Jakarta, Indonesia. The study included 199 CLI patients with type 2 diabetes mellitus (T2DM) who underwent endovascular revascularization from January 2008 to June 2018. The patients were followed up for 1 year after endovascular revascularization. Kaplan-Meier and Cox proportional hazard analysis was used to analyze the data.

RESULTS

1-year survival probability was 58.8%. Cox proportional hazard analysis showed that duration of diabetes (HR 3.52; 95% CI 1.34-9.22), anemia (HR 2.59; 95% CI 1.47-4.56), and smoking (HR 2.49; 95% CI 1.46-4.27) were significantly associated with mortality within 1 year after endovascular revascularization.

CONCLUSIONS

In T2DM patients with CLI, duration of diabetes, anemia and smoking were associated with a higher risk of mortality within 1 year post endovascular revascularization

Impact of Perioperative Blood Transfusion in Anemic Patients Undergoing Infra Inguinal Bypass

OBJECTIVE

Patients who present with lower extremity ischemia are frequently anemic and the optimal transfusion threshold for this cohort remains controversial. We sought to evaluate the impact of blood transfusion on postoperative major adverse cardiac events (MACE), including myocardial infarction, dysrhythmia, stroke, congestive heart failure, and 30-day mortality for these patients.

METHODS

All consecutive patients who underwent infra-inguinal bypass at our institution from 2011 to 2020 were included. Perioperative red blood cell transfusion was the primary exposure, and the primary outcome was MACE. Univariate and multivariable analyses were performed to assess the impact of patient and procedural variables, including red blood cell transfusion, stratified by hemoglobin (Hgb) nadir: <7, 7-8, and >8 g/dL.

RESULTS

Of the 287 patients reviewed for analysis, 146 (50.9%) had a perioperative transfusion (mean: 1.6 ± 3 units). Patients who received a transfusion had a mean nadir Hgb of 8.3 ± 1.0 g/dL, compared to 10.1 ± 1.7 g/dL without a transfusion. The overall incidence of MACE was 15.7% (45 of 287 patients). Univariate analysis demonstrated that MACE was associated with blood transfusion (P = 0.009), lower Hgb nadir (P = 0.02), and higher blood loss (P = 0.003). On multivariate analysis, transfusion was independently associated with MACE for patients with a Hgb nadir >8 g/dL (OR: 3.09; P = 0.006), but not for patients with Hgb nadir 7-8 g/dL (OR: 0.818; P = 0.77). Additionally, patients with MACE had significantly longer length of hospital stay than for patients without (13 vs. 7.7 days, P = 0.001).

CONCLUSIONS

For patients undergoing infra-inguinal bypass, receiving a red blood cell transfusion with a Hgb nadir >8 g/dL was associated with a 3-fold increase in MACE, with nearly twice the length of stay. For patients with a Hgb 7-8 g/dL, transfusion did not increase or reduce the incidence of MACE. These findings suggest no benefit of blood transfusion for patients with Hgb nadir >7 g/dL and harm for Hgb >8 g/dL, however causation cannot be proven due to the retrospective nature of the study and randomized studies are needed to confirm or refute these findings.

The Impact of Anemia on One-Year Amputation-Free Survival in Patients Undergoing Revascularization for Chronic Limb-Threatening Ischemia: A Retrospective Cohort Study

BACKGROUND

Anemia is potentially associated with increased morbidity and mortality following vascular surgery procedures. This study investigated whether peri-procedural anemia is associated with reduced 1-year amputation-free survival (AFS) in patients undergoing revascularization for chronic limb-threatening ischemia (CLTI).

METHODOLOGY

A retrospective analysis of patients diagnosed with CLTI between February 2018-February 2019, who subsequently underwent revascularization, was conducted. Hemoglobin concentration measured at index assessment was recorded and stratified by WHO criteria. Subsequent peri-procedural red blood cell transfusions (RBC) were also recorded. The primary outcome was 1-year AFS. Kaplan Meier survival analysis and Cox's proportional hazard modelling were conducted to assess the effect of anemia and peri-procedure transfusion on outcomes.

RESULTS

283 patients were analyzed, of which 148 (52.3%) were anemic. 53 patients (18.7%) underwent RBC transfusion. Patients with anemia had a significantly lower 1-year AFS (64.2% vs. 78.5%, P = 0.009). A significant difference in 1-year AFS was also observed based upon anemia severity (P = 0.008) and for patients who received RBC transfusion (45.3% vs 77.0%, P < 0.001). On multivariable analysis, moderately severe anemia was independently associated with increased risk of major amputation/death (aHR 1.90, 95% CI 1.06-3.38, P = 0.030). After adjusting for severity of baseline anemia, peri-procedural RBC transfusion was associated with a significant increase in the combined risk of major amputation/death (aHR 3.15, 95% CI 1.91-5.20, P < 0.001).

CONCLUSION

Moderately severe peri-procedural anemia and subsequent RBC transfusion are independently associated with reduced 1-year AFS in patients undergoing revascularization for CLTI. Future work should focus on investigating alternative measures to managing anemia in this cohort.

Peripheral arterial disease and anaemia. A review

Iron deficiency anaemia is highly prevalent worldwide. In the surgical patient, anaemia of any cause implies higher morbidity and mortality in the post-operative period. This is especially important in patients with peripheral artery disease, as they have very high rates of anaemia due to iron deficiency or other causes. In intermittent claudication, anaemia is a predictor of death in the medium term. Patients with critical ischaemia have higher prevalence of anaemia and it is an indicator of amputation and death in the medium term. Specific protocols need to be developed for these patients since the natural history of their disease does not allow for the correction of anaemia before surgery.

Anaemia: A risk factor for death and adverse outcomes following surgery for acute lower limb ischaemia

INTRODUCTION

Acute limb ischaemia (ALI) forms a significant part of the vascular surgery workload and carries with it high rates of morbidity and mortality. Anaemia is also common amongst vascular surgical patients and has been linked with poor outcomes in some subgroups. We aimed to assess the frequency of anaemia in patients with ALI and its impact on survival and complications following revascularisation to help direct future efforts to optimise outcomes in this patient group.

METHODS

A retrospective analysis of prospectively collected departmental data on patients undergoing surgical intervention for ALI between 2014 and 2018 was performed. Anaemia was defined as a pre-operative haemoglobin (Hb) of <120 g/L for women and <130 g/L for men. The primary outcome was overall survival, assessed with the Kaplan-Meier estimator, with application of Cox proportional hazard modelling to adjust for confounding covariates.

RESULTS

There were 158 patients who underwent treatment for ALI: 89 (56.3%) of these were non-anaemic with a mean Hb of 146 (SD = 18.4), and 69 (43.7%) were anaemic with a mean Hb of 106 (SD = 13.4). Anaemic patients had a significantly higher risk of death than their non-anaemic counterparts on univariate analysis (HR = 2.11, 95% CIs, 1.28-3.5, p = 0.0036). There was ongoing divergence in survival up to around 6 months between anaemic and non-anaemic groups. Under the Cox model, anaemia was similarly significant as a predictor of death (HR = 2.15, 95% CIs, 1.17-3.95, p = 0.013), accounting for recorded comorbidities, medication use and blood transfusion.

CONCLUSIONS

Anaemia is a significant and independent risk factor for death following revascularisation for ALI and can be potentially be modified. Vascular surgical centres should ensure they have robust pathways in place to identify and consider treating anaemia. There is scope for further work to assess how to best optimise a patient's levels of circulating haemoglobin.

The effects of preoperative moderate to severe anaemia on length of hospital stay: A propensity score-matched analysis in non-cardiac surgery patients

BACKGROUND

Anaemia is frequently recorded during preoperative screening and has been suggested to affect outcomes after surgery negatively.

OBJECTIVES

The objectives were to assess the frequency of moderate to severe anaemia and its association with length of hospital stay.

DESIGN

Post hoc analysis of the international observational prospective 'Local ASsessment of VEntilatory management during General Anaesthesia for Surgery' (LAS VEGAS) study.

PATIENTS AND SETTING

The current analysis included adult patients requiring general anaesthesia for non-cardiac surgery. Preoperative anaemia was defined as a haemoglobin concentration of 11 g dl-1 or lower, thus including moderate and severe anaemia according to World Health Organisation criteria.

MAIN OUTCOME MEASURES

The primary outcome was length of hospital stay. Secondary outcomes included hospital mortality, intra-operative adverse events and postoperative pulmonary complications (PPCs).

RESULTS

Haemoglobin concentrations were available for 8264 of 9864 patients. Preoperative moderate to severe anaemia was present in 7.7% of patients. Multivariable analysis showed that preoperative moderate to severe anaemia was associated with an increased length of hospital stay with a mean difference of 1.3 ((95% CI 0.8 to 1.8) days; P < .001). In the propensity-matched analysis, this association remained present, median 4.0 [IQR 1.0 to 5.0] vs. 2.0 [IQR 0.0 to 5.0] days, P = .001. Multivariable analysis showed an increased in-hospital mortality (OR 2.9 (95% CI 1.1 to 7.5); P  = .029), and higher incidences of intra-operative hypotension (36.3 vs. 25.3%; P < .001) and PPCs (17.1 vs. 10.5%; P = .001) in moderately to severely anaemic patients. However, this was not confirmed in the propensity score-matched analysis.

CONCLUSIONS

In this international cohort of non-cardiac surgical patients, preoperative moderate to severe anaemia was associated with a longer duration of hospital stay but not increased intra-operative complications, PPCs or in-hospital mortality.

TRIAL REGISTRATION

The LAS VEGAS study was registered at Clinicaltrials.gov, NCT01601223.

Novel bypass risk predictive tool is superior to the 5-Factor Modified Frailty Index in predicting postoperative outcomes

OBJECTIVE

This study aimed to develop risk predictive models of 30-day mortality, morbidity, and major adverse limb events (MALE) after bypass surgery for aortoiliac occlusive disease (AIOD) and to compare their performances with a 5-Factor Frailty Index.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program 2012-2017 Procedure Targeted Aortoiliac (Open) Participant Use Data Files were queried to identify all patients who had elective bypass for AIOD: femorofemoral bypass, aortofemoral bypass, and axillofemoral bypass (AXB). Outcomes assessed included mortality, major morbidity, and MALE within 30 days postoperatively. Major morbidity was defined as pneumonia, unplanned intubation, ventilator support for >48 hours, progressive or acute renal failure, cerebrovascular accident, cardiac arrest, or myocardial infarction. Demographics, comorbidities, procedure type, and laboratory values were considered for inclusion in the risk predictive models. Logistic regression models for mortality, major morbidity and MALE were developed. The discriminative ability of these models (C-indices) were compared with that of the 5-Factor Modified Frailty Index (mFI-5): a general frailty tool determined from diabetes, functional status, history of chronic obstructive pulmonary disease, history of congestive heart failure, and hypertension. Calculators were derived using the most significant variables for each of the three risk predictive models.

RESULTS

A total of 2612 cases (mean age 65.0, 60% male) were identified, of which 1149 (44.0%) were femorofemoral bypass, 1138 (43.6%) were aortofemoral bypass, and 325 (12.4%) were axillofemoral bypass. Overall, the rates of mortality, major morbidity, and MALE were 2.0%, 8.5%, and 4.9%, respectively. Twenty preoperative risk factors were considered for incorporation in the risk tools. Apart from procedure type, age was the most statistically significant predictor of both mortality and morbidity. Preoperative anemia and critical limb ischemia were the most significant predictors of MALE. All three constructed models demonstrated significantly better discriminative ability (P < .001) on the outcomes of interest as compared with the mFI-5.

CONCLUSIONS

Our models outperformed the mFI-5 in predicting 30-day mortality, major morbidity, and adverse limb events in patients with AIOD undergoing elective bypass surgery. Calculators were created using the most statistically significant variables to help calculate individual patient's postoperative risks and allow for better informed consent and risk-adjusted comparison of provider outcomes.

Anemia at Discharge in Elderly Trauma Patients is Not Associated with Six-Month Mortality

Few studies have evaluated outcomes in geriatric trauma patients discharged with anemia. Our hypothesis was that anemia at discharge was not associated with six-month mortality. A 22-month retrospective study of trauma patients ≥ 65 years was conducted from 2015 to 2016. The end point was six-month mortality. The degree of anemia at admission (admission hemoglobin [AHb]) and discharge (discharge hemoglobin [DHb]) was categorized as follows based on hemoglobin (Hb) (g/dL): I (>10), II (>9 and ≤10), III (>8 and ≤9), and IV (≤8). Univariate analysis and multivariate analysis were performed to determine the association of AHb and DHb with the end point. Nine hundred forty-nine patients were analyzed (median age, 82 years). Six-month mortality was 11 per cent. Mortality was associated with AHb by univariate analysis (I:10% [84/831]; II: 13% [9/67]; III: 22% [7/32]; and IV: 26% [5/19]) ( P = 0.003). DHb was not associated with mortality (I:11% [65/613]; II: 12% [21/183]; III: 10% [12/116]; and IV: 18% [7/39]) ( P = 0.37). Logistic regression found that AHb category IV, age, and chronic kidney disease were independently associated with the end point. In geriatric patients, the severity of anemia at admission and not at discharge predicted six-month mortality. Discharging patients with an Hb of ≤8 g/dL was not adversely associated with mortality.

Patient Blood Management: Recommendations From the 2018 Frankfurt Consensus Conference

IMPORTANCE

Blood transfusion is one of the most frequently used therapies worldwide and is associated with benefits, risks, and costs.

OBJECTIVE

To develop a set of evidence-based recommendations for patient blood management (PBM) and for research.

EVIDENCE REVIEW

The scientific committee developed 17 Population/Intervention/Comparison/Outcome (PICO) questions for red blood cell (RBC) transfusion in adult patients in 3 areas: preoperative anemia (3 questions), RBC transfusion thresholds (11 questions), and implementation of PBM programs (3 questions). These questions guided the literature search in 4 biomedical databases (MEDLINE, EMBASE, Cochrane Library, Transfusion Evidence Library), searched from inception to January 2018. Meta-analyses were conducted with the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) methodology and the Evidence-to-Decision framework by 3 panels including clinical and scientific experts, nurses, patient representatives, and methodologists, to develop clinical recommendations during a consensus conference in Frankfurt/Main, Germany, in April 2018.

FINDINGS

From 17 607 literature citations associated with the 17 PICO questions, 145 studies, including 63 randomized clinical trials with 23 143 patients and 82 observational studies with more than 4 million patients, were analyzed. For preoperative anemia, 4 clinical and 3 research recommendations were developed, including the strong recommendation to detect and manage anemia sufficiently early before major elective surgery. For RBC transfusion thresholds, 4 clinical and 6 research recommendations were developed, including 2 strong clinical recommendations for critically ill but clinically stable intensive care patients with or without septic shock (recommended threshold for RBC transfusion, hemoglobin concentration <7 g/dL) as well as for patients undergoing cardiac surgery (recommended threshold for RBC transfusion, hemoglobin concentration <7.5 g/dL). For implementation of PBM programs, 2 clinical and 3 research recommendations were developed, including recommendations to implement comprehensive PBM programs and to use electronic decision support systems (both conditional recommendations) to improve appropriate RBC utilization.

CONCLUSIONS AND RELEVANCE

The 2018 PBM International Consensus Conference defined the current status of the PBM evidence base for practice and research purposes and established 10 clinical recommendations and 12 research recommendations for preoperative anemia, RBC transfusion thresholds for adults, and implementation of PBM programs. The relative paucity of strong evidence to answer many of the PICO questions supports the need for additional research and an international consensus for accepted definitions and hemoglobin thresholds, as well as clinically meaningful end points for multicenter trials.

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.

Preoperative anemia associated with adverse outcomes after infrainguinal bypass surgery in patients with chronic limb-threatening ischemia

OBJECTIVE

Preoperative anemia in elderly patients undergoing surgery is prevalent and associated with adverse events; however, the interaction with other risk factors in patients with chronic limb-threatening ischemia (CLTI) is not well described. The purpose of this study was to assess the association between lower hematocrit (HCT) levels on admission and postoperative outcomes after infrainguinal bypass surgery.

METHODS

Patients with CLTI undergoing nonemergent infrainguinal bypass were identified in the targeted vascular module of National Surgical Quality Improvement Program (NSQIP; 2011-2014). The 30-day outcomes were compared across preoperative HCT levels: severe (≤29%), moderate (29.1%-34%), mild (34.1%-39%), or no anemia (>39%), with no anemia serving as the reference group for all analyses. Independent associations between levels of anemia and postoperative outcomes were established using multivariable logistic regression. A sensitivity analysis was performed to assess interactions between preoperative anemia and blood transfusions.

RESULTS

We identified 5081 patients undergoing bypass, of which 741 (15%) had severe, 1317 (26%) moderate, 1516 (30%) mild, and 1507 (30%) no anemia. Anemic patients were older and more commonly suffered from tissue loss and comorbidities (eg, hypertension, diabetes, and renal insufficiency; all P < .001). After adjustment for baseline conditions, mortality was higher in those with severe anemia (3.1%; odds ratio [OR], 2.8; 95% confidence interval [CI], 1.3-6.3) and moderate anemia (3.0%; OR, 2.6; 95% CI, 1.2-5.5) compared with those without anemia (0.7%). Severe anemia was independently associated with major amputation (6.9% vs 3.3%; OR, 1.6; 95% CI, 1.01-2.6) compared with no anemia. Anemia on admission was additionally associated with several other adverse outcomes, such as major adverse cardiovascular event (MACE; severe: OR, 1.9; 95% CI, 1.1-3.0; moderate: OR, 1.9; 95% CI, 1.3-2.9; mild: OR, 1.6; 95% CI, 1.1-2.4) and unplanned return to the operating room (severe: OR, 1.6; 95% CI, 1.2-2.1; moderate: OR, 1.5; 95% CI, 1.2-1.8; mild, OR: 1.3; 95% CI, 1.03-1.6). Moreover, mortality associated with preoperative anemia was not different in patients receiving postoperative blood transfusions compared with those who did not, whereas MACE was significantly higher in patients with preoperative anemia and blood transfusions (interaction; P < .001).

CONCLUSIONS

Mortality and major adverse events in CLTI patients undergoing infrainguinal bypass are inversely associated with preoperative HCT levels, with the highest event rates in the most severely anemic patients. The correlation between anemia and MACE-but not mortality-was stronger in those patients receiving postoperative blood transfusions. Further research is needed to define an appropriate transfusion threshold, and attention should be focused on how to best optimize anemic CLTI patients before intervention.