Is heparin reversal with protamine after carotid endarterectomy dangerous?

A Meta-Analysis of Using Protamine for Reducing the Risk of Hemorrhage During Carotid Recanalization: Direct Comparisons of Post-operative Complications

Background: Protamine can decrease the risk of hemorrhage during carotid recanalization. However, it may cause severe side effects. There is no consensus on the safety and efficacy of protamine during surgery. Thus, we conduct a comprehensive review and meta-analysis to compare the differences between the protamine and the no-protamine group.

Method: We systematically obtained literature from Medline, Google Scholar, Cochrane Library, and PubMed electronic databases. All four databases were scanned from 1937 when protamine was first adopted as a heparin antagonist until February 2021. The reference lists of identified studies were manually checked to determine other eligible studies that qualify. The articles were included in this meta-analysis as long as they met the criteria of PICOS; conference or commentary articles, letters, case report or series, and animal observation were excluded from this study. The Newcastle-Ottawa Quality Assessment Scale and Cochrane Collaboration’s tool are used to assess the risk of bias of each included observational study and RCT, respectively. Stata version 12.0 statistical software (StataCorp LP, College Station, Texas) was adopted as statistical software. When I2 < 50%, we consider that the data have no obvious heterogeneity, and we conduct a meta-analysis using the fixed-effect model. Otherwise, the random-effect model was performed.

Result: A total of 11 studies, consisting of 94,618 participants, are included in this study. Our analysis found that the rate of wound hematoma had a significant difference among protamine and no-protamine patients (OR = 0.268, 95% CI = 0.093 to 0.774, p = 0.015). Furthermore, the incidence of hematoma requiring re-operation (0.7%) was significantly lower than that of patients without protamine (1.8%). However, there was no significant difference in the incidence of stroke, wound hematoma with hypertension, transient ischemic attacks (TIA), myocardial infarction (MI), and death.

Conclusion: Among included participants undergoing recanalization, the use of protamine is effective in reducing hematoma without increasing the risk of having other complications. Besides, more evidence-based performance is needed to supplement this opinion due to inherent limitations.

Optimization of Heparin Monitoring with Anti-FXa Assays and the Impact of Dextran Sulfate for Measuring All Drug Activity

Heparins, unfractionated or low molecular weight, are permanently in the spotlight of both clinical indications and laboratory monitoring. An accurate drug dosage is necessary for an efficient and safe therapy. The one-stage kinetic anti-FXa assays are the most widely and universally used with full automation for large series, without needing exogenous antithrombin. The WHO International Standards are available for UFH and LMWH, but external quality assessment surveys still report a high inter-assay variability. This heterogeneity results from the following: assay formulation, designed without or with dextran sulfate to measure all heparin in blood circulation; calibrators for testing UFH or LMWH with the same curve; and automation parameters. In this study, various factors which impact heparin measurements are reviewed, and we share our experience to optimize assays for testing all heparin anticoagulant activities in plasma. Evidence is provided on the usefulness of low molecular weight dextran sulfate to completely mobilize all of the drug present in blood circulation. Other key factors concern the adjustment of assay conditions to obtain fully superimposable calibration curves for UFH and LMWH, calibrators' formulations, and automation parameters. In this study, we illustrate the performances of different anti-FXa assays used for testing heparin on UFH or LMWH treated patients' plasmas and obtained using citrate or CTAD anticoagulants. Comparable results are obtained only when the CTAD anticoagulant is used. Using citrate as an anticoagulant, UFH is underestimated in the absence of dextran sulfate. Heparin calibrators, adjustment of automation parameters, and data treatment contribute to other smaller differences.

Abnormal Expression of YAP Is Associated With Proliferation, Differentiation, Neutrophil Infiltration, and Adverse Outcome in Patients With Nasal Inverted Papilloma

Background

Nasal inverted papilloma (NIP) is a common benign tumor. Yes-associated protein (YAP) is the core effector molecule of the Hippo pathway, which regulates the proliferation and differentiation of airway epithelium. While its role in proliferation may be connected to NIP formation, no definitive association has been made between them.

Methods

We compared the difference of YAP expression and proliferation level between the control inferior turbinate, NP (nasal polyps), and NIP groups. In addition, we further used PCR, immunofluorescence, and immunohistochemistry to investigate YAP's role in the proliferation and differentiation of the nasal epithelium and inflammatory cell infiltration, correlating them with different grades of epithelial remodeling. We further used an IL-13 remodeling condition to investigate YAP's role in differentiation in an in vitro air-liquid interface (ALI) human nasal epithelial cell (hNECs) model. Finally, we also explored the correlation between YAP expression and clinical indicators of NIP.

Results

The expression of YAP/active YAP in the NIP group was significantly higher than that in the NP group and control group. Moreover, within the NIP group, the higher grade of epithelial remodeling was associated with higher YAP induced proliferation, leading to reduced ciliated cells and goblet cells. The finding was further verified using an IL-13 remodeling condition in differentiating ALI hNECs. Furthermore, YAP expression was positively correlated with proliferation and neutrophil infiltration in NIP. YAP expression was also significantly increased in NIP patients with adverse outcomes.

Conclusion

Abnormal expression of YAP/active YAP is associated with proliferation, differentiation, neutrophil infiltration, and adverse outcome in NIP and may present a novel target for diagnosis and intervention in NIP.

Protamine use in transfemoral carotid artery stenting is not associated with an increased risk of thromboembolic events

BACKGROUND

Protamine use in carotid endarterectomy has been shown to be associated with fewer perioperative bleeding complications without higher rates of thromboembolic events. However, the effect of protamine use on complications after transfemoral carotid artery stenting (CAS) is unclear, and concerns remain about thromboembolic events.

METHODS

A retrospective review was performed for patients undergoing transfemoral CAS in the Vascular Quality Initiative from March 2005 to December 2018. We assessed in-hospital outcomes using propensity score-matched cohorts of patients who did and did not receive protamine. The primary outcome was in-hospital stroke or death. Secondary outcomes included bleeding complications, stroke, death, transient ischemic attack, myocardial infarction, and congestive heart failure exacerbation. Bleeding complications were categorized as bleeding resulting in intervention or blood transfusions.

RESULTS

Of the 17,429 patients undergoing transfemoral CAS, 2697 (15%) patients received protamine. We created 2300 propensity score-matched pairs of patients who did and did not receive protamine. There were no statistically significant differences in stroke or death between the two cohorts (protamine, 2.5%; no protamine, 2.9%; relative risk [RR], 0.85; 95% confidence interval [CI], 0.60-1.21; P = .37). Protamine use was not associated with statistically significant differences in perioperative bleeding complications resulting in interventional treatment (0.9% vs 0.5%; RR, 2.10; 95% CI, 0.99-4.46; P = .05) or blood transfusion (1.2% vs 1.2%; RR, 0.92; 95% CI, 0.53-1.61; P = .78). There were also no statistically significant differences for the individual outcomes of stroke (1.8% vs 2.3%; RR, 0.78; 95% CI, 0.52-1.16; P = .22), death (0.9% vs 0.8%; RR, 1.17; 95% CI, 0.62-2.19; P = .63), transient ischemic attack (1.4% vs 1.3%; RR, 1.10; 95% CI, 0.67-1.82; P = .70), myocardial infarction (0.5% vs 0.4%; RR, 1.20; 95% CI, 0.52-2.78; P = .67), or heart failure exacerbation (1.0% vs 0.9%; RR, 1.05; 95% CI, 0.58-1.90; P = .88). Protamine use in patients presenting with symptomatic carotid stenosis was associated with lower risk of stroke or death (3.0% vs 4.3%; RR, 0.69; 95% CI, 0.47-0.998; P = .048), whereas there were no statistically significant differences in stroke or death with protamine use in asymptomatic patients (1.6% vs 1.0%; RR, 1.63; 95% CI, 0.67-3.92; P = .28).

CONCLUSIONS

Heparin reversal with protamine after transfemoral CAS is not associated with an increased risk of thromboembolic events, and its use in symptomatic carotid disease is associated with a lower risk of stroke or death.

American Society of Hematology 2018 guidelines for management of venous thromboembolism: optimal management of anticoagulation therapy

BACKGROUND

Clinicians confront numerous practical issues in optimizing the use of anticoagulants to treat venous thromboembolism (VTE).

OBJECTIVE

These evidence-based guidelines of the American Society of Hematology (ASH) are intended to support patients, clinicians and other health care professionals in their decisions about the use of anticoagulants in the management of VTE. These guidelines assume the choice of anticoagulant has already been made.

METHODS

ASH formed a multidisciplinary guideline panel balanced to minimize potential bias from conflicts of interest. The McMaster University GRADE Centre supported the guideline development process, including updating or performing systematic evidence reviews. The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess evidence and make recommendations, which were subject to public comment.

RESULTS

The panel agreed on 25 recommendations and 2 good practice statements to optimize management of patients receiving anticoagulants.

CONCLUSIONS

Strong recommendations included using patient self-management of international normalized ratio (INR) with home point-of-care INR monitoring for vitamin K antagonist therapy and against using periprocedural low-molecular-weight heparin (LMWH) bridging therapy. Conditional recommendations included basing treatment dosing of LMWH on actual body weight, not using anti-factor Xa monitoring to guide LMWH dosing, using specialized anticoagulation management services, and resuming anticoagulation after episodes of life-threatening bleeding.

Anticoagulants

Anticoagulants are effective in the prevention and treatment of a variety of arterial and venous thrombotic disorders but are associated with an increased risk of serious bleeding complications. Based on well documented studies of patients using vitamin K antagonists the incidence of major bleeding is 0.5%/year and the incidence of intracranial bleeding is 0.2%/year, however, in real life practice this incidence may be even higher. Risk factors for bleeding are the intensity of anticoagulation, the management strategy to keep the anticoagulant effect in the desired range, and patient characteristics. Recently, a new generation of anticoagulants have been developed and is currently evaluated in clinical trials. Initial results show a similar or superior efficacy over conventional anticoagulant agents with a good safety profile. In case of serious bleeding complications in a patient who uses vitamin K antagonists, this anticoagulant treatment can be quickly reversed by administration of vitamin K or coagulation factor concentrates. For the newer anticoagulants, quick reversal strategies are more cumbersome, although some interventions, including prothrombin complex concentrates, show promising results in initial experimental studies.

Using protamine can significantly reduce the incidence of bleeding complications after carotid endarterectomy without increasing the risk of ischemic cerebral events

BACKGROUND

Controversy persists regarding the use of protamine sulfate (PS) during carotid endarterectomy (CEA), chiefly because of conflicting experiences reporting both less bleeding and a higher stroke risk. The goal of the present study was to test the hypothesis that reversing heparin with PS after CEA significantly reduces the incidence of bleeding complications without increasing the risk of postoperative stroke.

METHODS

From January 2010 to December 2012 all consecutive patients undergoing CEA under general anesthesia at our institution received 5,000 U of heparin prior to carotid clamping, which was partially (half-dose) reversed with PS 25 mg immediately after declamping (group I). Heparinization had never been reversed with PS in earlier CEAs performed from 1998 to 2009 at the same institution (group II). All patients were assessed preoperatively and postoperatively by a neurologist, and cerebral magnetic resonance imaging was performed in all group I patients to exclude any silent cerebral infarction. End points of the study were bleeding complications, perioperative (30-day) stroke, and death.

RESULTS

Overall, 219 CEAs (201 patients) were performed in group I, and 1,458 CEAs (1,294 patients) in group II. Demographics, risk factors, and preoperative antiplatelet medication were comparable in the two groups. The incidence of adverse events (group I vs group II) was as follows: stroke (0 vs 0.5 % [8/1,458], p = 0.27); death (0 vs 0 %); neck bleeding (0 vs 8.2 % [120/1,458], p < 0.001).

CONCLUSIONS

The results of the present study demonstrate that (1) partially neutralizing heparin with PS after CEA can significantly reduce the risk of bleeding complications, and (2) there is no association between the administration of PS and the incidence of postoperative stroke.

Predictors of cervical bleeding after carotid endarterectomy

BACKGROUND

The aim of this study is to determine the incidence of severe cervical bleeding requiring reintervention after carotid endarterectomy (CEA), to identify its predictive parameters, and to find out the influence of these on major complications.

METHODS

This was a retrospective review of 502 CEAs carried out in 455 consecutive patients between 1995-2011 in our institution. The end points were: postoperative cervical bleeding that required reoperation and major postoperative complications (i.e., stroke, myocardial infarction, and death). Patients' demographics, antiplatelet and anticoagulant treatment, anaesthetic technique, surgical details, and perioperative management were registered. The end point predictors were univariate and multivariate analyzed.

RESULTS

Neck bleeding after CEA occurred in 42 cases (8.4%), requiring reoperation in 28 cases (5.6%). In the univariate analysis, chronic anticoagulation and anticoagulation 24 hours before surgery were associated with reoperation for bleeding (16.6% vs. 4.8% [P = 0.02] and 17.8% vs. 4.7% [P = 0.014], respectively). The agent used for antiplatelet treatment before surgery was related to reoperation in the univariate analysis and was the only factor with statistical significance in the multivariate analysis: acetylsalicylic acid (ASA) 100 mg (2.4%), ASA 300 mg (1.5%), clopidogrel 75 mg (7.8%), ASA 100 mg associated with clopidogrel (3.3%), triflusal (5.5%), and ticlopidine (2.2%); there was a higher incidence of reoperation only in the group of patients who had taken clopidogrel 24 hours before CEA (4.7% vs. 1.05% [P = 0.06], respectively) but without statistical significance (odds ratio: 2; 95% confidence interval: 0.95-4.84). No reoperations were registered using vein patch compared to prosthetic patch (0% vs. 6.1% [P = 0.028]). Conversion to general anesthesia (22.2% vs. 4.9% [P = 0.014]) and noncontrollable postoperative hypertension (6.9% vs. 2.5% [P = 0.028]) were associated with a higher rate of reoperation. There were no statistically significant differences in the reoperation rates related to bleeding for anesthetic technique (local versus general), surgical procedure (classic endarterectomy versus eversion technique), type of prosthetic patch (Dacron/politetrafluoroethylene), use of shunt, intraoperative dose of heparin, protamine reversal, activated clotting time monitoring, or surgeon qualification level. The combined rate of stroke mortality was 2.6%. Reoperation for bleeding was not associated with an increased rate of thrombosis, stroke, death, or injury of cranial nerves.

CONCLUSIONS

Postoperative severe bleeding after carotid surgery in our institution is not an uncommon complication. Its incidence is within the range reported in the literature, but it is not associated with major complications or mortality. Antiplatelet treatment with clopidogrel is the main risk factor associated with reintervention. Other factors, such as coagulation control, postoperative hypertension management, and the use of an autologous patch, could help reduce its incidence.

Shared quality data are associated with increased protamine use and reduced bleeding complications after carotid endarterectomy in the Vascular Study Group of New England

OBJECTIVE

The goal of this study was to evaluate whether protamine usage after carotid endarterectomy (CEA) increased within the Vascular Study Group of New England (VSGNE) in response to studies indicating that protamine reduces bleeding complications associated with CEA without increasing the risk of stroke.

METHODS

We reviewed 10,059 CEAs, excluding concomitant coronary bypass, performed within the VSGNE from January 2003 to July 2012. Protamine use and reoperation for bleeding were evaluated monthly using statistical process control. Twelve centers and 77 surgeons entering the VSGNE between 2003 and 2008 were classified as original participants, and 14 centers and 60 surgeons joining after May 2009 were considered new. Protamine use for surgeons was categorized as rare (<10%), selective (10%-80%), or routine (>80%). Outcome measures were in-hospital reoperation for bleeding, postoperative myocardial infarction (POMI), and stroke or death.

RESULTS

Two significant increases occurred in protamine use for all VSGNE centers over time. From 2003 to 2007, the protamine rate remained stable at 43%. In 2008, protamine usage increased to 52% (P < .01), coincident with new centers joining the VSGNE. Protamine usage then increased to 62% in 2010 (P < .01), shortly after the presentations of the data showing a benefit of protamine. This effect was due to 10 surgeons in the original VSGNE centers who increased their usage of protamine: six surgeons from rare use to selective use and four surgeons to routine use. Reoperation for bleeding was reduced by 0.84% (relative risk reduction, 57.2%) in patients who received protamine (0.6% vs 1.44%; P < .001). There were no differences in POMI (1.1% vs 1.09%) or stroke or death (1.1% vs 1.03%) between protamine treated and untreated patients, respectively. Reoperation for bleeding was decreased for surgeons who used protamine routinely (0.5%; P < .001) compared with selective (1.4%) and rare users (1.5%) of protamine. There were no differences in POMI (0.9%, 1.2%, 1.1%; P = .720) and stroke or death rates (1.0%, 1.2%, 1.0%; P = .656) for rare, selective, and routine users of protamine.

CONCLUSIONS

Protamine use increased over time by VSGNE surgeons, most significantly after the presentations of VSGNE-derived data showing the benefit of protamine, and was associated with a decrease in reoperation for bleeding. Improvements in processes of care and outcomes can be achieved in regional quality groups by sharing safety and efficacy data.

Protamine does not increase risk of stroke in patients with elective carotid stenting

BACKGROUND AND PURPOSE

Reversal of anticoagulation with protamine might predispose to a higher risk of stroke in patients with carotid stenting. We evaluated a national, multihospital patient database to examine the risk of stroke in patients with carotid stenting receiving protamine compared with those who did not.

METHODS

The Premier Perspective database was used to identify patients who were electively hospitalized for carotid stenting from 2006 through 2011. The incidence of in-hospital mortality and morbidity was compared between patients who did and did not receive protamine after propensity score adjustment via 1:1 matching to reduce selection bias.

RESULTS

Of 6664 patients with carotid stenting treated at 193 hospitals, 556 (8%) received protamine on the day of the procedure. After matching by propensity score, patients who received protamine had a similar likelihood of stroke or transient ischemic attack (P=0.77), in-hospital mortality (P=0.12), discharge to long-term care (P=0.15), and access site complications (P=0.90) as compared with patients who did not receive protamine.

CONCLUSIONS

Protamine administration is not associated with additional risk of adverse events after carotid stenting.

Safety of carotid endarterectomy while on clopidogrel (Plavix)

Object

Many patients undergoing carotid endarterectomy (CEA) regularly take clopidogrel, a permanent platelet inhibitor. The authors sought to determine whether taking clopidogrel in the period before CEA leads to more bleeding or other complications.

Methods

The authors performed a retrospective, institutional review board–approved review of 182 consecutive patients who underwent CEA. Clinical, radiographic, and surgical data were gleaned from hospital and clinic records. Analysis was based on the presence or absence of clopidogrel in patients undergoing CEA and was performed twice by considering clopidogrel use within 8 days and within 5 days of surgery to define the groups.

Results

Taking clopidogrel within 8 days before surgery resulted in no statistical increase in any measure of morbidity or death. Taking clopidogrel within 5 days was associated with a small but significant increase in operative blood loss and conservatively managed postoperative neck swelling. No measure of permanent morbidity or death was increased in either clopidogrel group.

Conclusions

Findings in this study support the safety of preoperative clopidogrel in patients undergoing CEA.

Antiplatelet agents and risk factors for bleeding postcarotid endarterectomy

BACKGROUND

Antiplatelet therapy has been implicated as a risk factor for wound hematoma formation after carotid endarterectomy (CEA). Given the increasing use of alternative antiplatelet drugs acting through differing inhibitory pathways, we audited the incidence of re-operation for bleeding post-CEA.

METHODS

Data were prospectively recorded on all patients undergoing CEA in Leicester, United Kingdom between November 1997 and October 2001. The data from those requiring exploration for bleeding were studied on a case-controlled basis using paired age and sex-matched controls from within the overall database. Assessment of the patients' demographics, drug history, and intraoperative and postoperative care was made.

RESULTS

A total of 448 patients were reviewed and 27 (6.03%) cases of postoperative bleeding were identified which required exploration. Despite the prevalent use of antiplatelet drugs before surgery, there was no increased risk of bleeding associated with their use identified on univariate analysis. Patients who underwent re-exploration for bleeding had a significantly greater prevalence of post-CEA hypertension (21/27 cases vs. 25/54 controls, respectively; p = 0.014). Patients who underwent surgical re-exploration for bleeding also had a greater transfusion requirement (1.33 ± 1.3 vs. 0.02 ± 0.1 units; p ≤ 0.0001) and a longer hospital stay (4.9 ± 2.2 days vs. 2.9 ± 2.3 days; p = 0.001) although there was no increase in morbidity or mortality.

CONCLUSION

The use of newer antiplatelet drugs before surgery was not associated with an increased risk of bleeding after CEA in this study. Tight control of blood pressure, both pre- and postsurgery, appears to be important, and a protocol for the management of this condition is recommended.

Protamine reduces bleeding complications associated with carotid endarterectomy without increasing the risk of stroke

OBJECTIVES

Controversy persists regarding the use of protamine during carotid endarterectomy (CEA) based on prior conflicting reports documenting both reduced bleeding as well as increased stroke risk. The purpose of this study was to determine the effect of protamine reversal of heparin anticoagulation on the outcome of CEA in a contemporary multistate registry.

METHODS

We reviewed a prospective regional registry of 4587 CEAs in 4311 patients performed by 66 surgeons from 11 centers in Northern New England from 2003-2008. Protamine use varied by surgeon (38% routine use, 44% rare use, 18% selective use). Endpoints were postoperative bleeding requiring reoperation as well as potential thrombotic complications, including stroke, death, and myocardial infarction (MI). Predictors of endpoints were determined by multivariate logistic regression after associated variables were identified by univariate analysis.

RESULTS

Of the 4587 CEAs performed, 46% utilized protamine, while 54% did not. Fourteen patients (0.64%) in the protamine-treated group required reoperation for bleeding compared with 42 patients (1.66%) in the untreated cohort (P = .001). Protamine use did not affect the rate of MI (1.1% vs 0.91%, P = .51), stroke (0.78% vs 1.15%, P = .2), or death (0.23% vs 0.32%, P = .57) between treated and untreated patients, respectively. By multivariate analysis, protamine (odds ratio [OR] 0.32, 95% confidence interval [CI], 0.17-0.63; P = .001) and patch angioplasty (OR 0.46, 95% CI, 0.26-0.81; P = .007) were independently associated with diminished reoperation for bleeding. A single center was associated with a significantly higher rate of reoperation for bleeding (OR 6.47, 95% CI, 3.02-13.9; P < .001). Independent of protamine use, consequences of reoperation for bleeding were significant, with a four-fold increase in MI, a seven-fold increase in stroke, and a 30-fold increase in death.

CONCLUSION

Protamine reduced serious bleeding requiring reoperation during CEA without increasing the risk of MI, stroke, or death, in this large, contemporary registry. In light of significant complications referable to bleeding, liberal use of protamine during CEA appears warranted.

Emergency reversal of antithrombotic treatment

The most important adverse effect of antithrombotic treatment is the occurrence of bleeding. In case of serious or even life-threatening bleeding in a patient who uses anticoagulant agents or when a patient on anticoagulants needs to undergo an urgent invasive procedure, anticoagulant treatment can be reversed by various specific strategies. Heparin and heparin derivatives can be counteracted by protamine sulphate, whereas the anticoagulant effect of vitamin K antagonists may be neutralized by administration of vitamin K or prothrombin complex concentrates. The anti-hemostatic effect of aspirin and other anti-platelet strategies can be corrected by the administration of platelet concentrate or desmopressin, if needed. Recently, a new generation of anticoagulants with a greater specificity towards activated coagulation factors has been introduced and most of these agents are presently being evaluated in clinical studies. The new generation anticoagulants include specific inhibitors of factor IIa, factor Xa (including pentasaccharides) and agents that interfere with tissue factor activity. A limitation of this new class of anticoagulants may be the lack of an appropriate strategy to reverse the effect if a bleeding event occurs, although in some cases the administration of recombinant factor VIIa may be an option.