Relationship of protamine dosing with postoperative complications of carotid endarterectomy

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.

Use of protamine sulfate during transfemoral transcatheter aortic valve implantation - a preliminary assessment of administration rate and impact on complications

Introduction

Bleeding complications after transcatheter aortic valve implantation (TAVI) are an important issue and negatively affect survival. The rate and impact of protamine sulfate (PS) administration on bleeding complications after TAVI remain unclear.

Aim

To assess the impact of PS on bleeding complications after TAVI.

Material and methods

Between March 2010 and November 2016 two hundred fifty-eight patients qualified for TAVI in one academic center were screened. Baseline, procedural and follow-up data up to 30 days were collected and analyzed. The primary endpoint (PE) was major bleeding according to the Valve Academic Research Consortium up to 48 h after the procedure.

Results

Overall, 186 patients (96 females, mean age: 80 years) met the inclusion criteria. Thirty-nine (21%) subjects received PS. PE occurred in 24.7% of the study population. There were no significant differences in terms of the PE rate between the groups (25.6% in the PS group and 24.7% in the remaining cohort, p = 0.9, odds ratio (OR) = 1.05, confidence interval (CI): 0.47–2.4, p = 0.9). Multivariate analysis identified female gender (OR = 2.2, CI: 1.08–4.4, p = 0.03) as an independent predictor of PE occurrence. Similarly, female gender (OR = 2, CI: 1.06–3.84, p = 0.03) as well as general anesthesia (GA, OR = 2.23, CI: 1.13–4.63, p = 0.02) and dose of unfractionated heparin per kilogram (UFH/kg, OR = 1.02, CI: 1–1.03 per 1 IU increment, p = 0.02) predicted the occurrence of a composite of major and minor bleeding.

Conclusions

In this analysis, PS administration did not decrease the PE rate. Female gender predicted PE occurrence. Randomized, placebo-controlled trials are required to accurately assess the impact of PS.

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.

Antithrombotic therapy following transcatheter aortic valve implantation: what challenge do we face?

The issue of stroke and bleeding events following transcatheter aortic valve implantation (TAVI) and its relation with antithrombotic regimens before, during and after the procedure is increasingly recognized as an important issue. While dedicated trials are ongoing, there is no clear evidence at present on the best antithrombotic regimen in the context of TAVI. In this article, we will go through the mechanisms involved in embolic and bleeding complications of TAVI, and we will discuss the key aspects of antithrombotic treatment in patients undergoing TAVI.

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.

Chemically modified poly(2-hydroxyethyl methacrylate) cryogel for the adsorption of heparin

Various clinical procedures, such as cardiovascular surgery or extracorporeal blood purification, involve systemic anticoagulation using heparin. High concentrations of circulating heparin require neutralization due to possible serious bleeding complications. The intravenous administration of the heparin antagonist protamine sulfate is routinely clinically performed, but is frequently associated with adverse reactions. Therefore, there is a need for a valid and safe alternative to achieve extracorporeal heparin removal from blood or plasma, such as a filter, a matrix, or an adsorbent. Here, we describe the development of a macroporous poly(2-hydroxyethyl methacrylate)-based monolithic cryogel functionalized with l-lysine (pHEMA-lys) and the characterization of its selective heparin adsorption. The maximum binding capacity was quantified in vitro using aqueous and serum solutions under static and dynamic conditions, and fresh human plasma under static conditions. The pHEMA-lys bound 40,500 IU and 32,500 IU heparin/g cryogel at the equilibrium in aqueous solution and 50% serum, respectively. In human plasma spiked with 100 IU/mL of heparin, the binding was still highly efficient (4330 IU/g cryogel after 30 min, i.e., 87% of the initial concentration). The cryogels showed good blood compatibility, as indicated by negligible adsorption of albumin, antithrombin III, and total protein, and may thus be suitable for extracorporeal heparin removal.

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.

Cervical Hematoma Following Carotid Endarterectomy is Morbid and Preventable

Objective:

Cervical hematoma (CH) following carotid endarterectomy (CEA) is a serious complication. We reviewed 12 years of CEA for CH requiring operative evacuation to determine its impact on the patient outcome and relationship to perioperative pharmacotherapy.

Methods:

A total of 2643 CEAs were reviewed. In all, 57 CHs requiring operative evacuation were compared to all the patients for general characteristics and with a case-controlled cohort group for pharmacologic details.

Results:

The occurrence of CH was stable from 1994 to 1998 and then increased from 1999 to 2003. The CH increased operative mortality, neurologic complications, adverse cardiac events, and cranial nerve injury. Combined platelet inhibition and dextran alone increased the risk of CH. The CH rate dropped by 65% after the observations were reported to the vascular surgeons.

Conclusion:

The CH following CEA requiring operative evacuation is associated with increased postoperative mortality and cardiac and neurologic morbidity. Combined platelet inhibition, use of dextran, and elevated creatinine are causally related to CH. Physician awareness and modified pharmacotherapy have decreased the problem.

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.

Is heparin reversal with protamine after carotid endarterectomy dangerous?

OBJECTIVE

Although systemic heparinisation is routine during CEA, reversal with protamine is controversial with 3 studies suggesting increased peri-operative stroke rates and 3 no effect. None included independent peer-review.

DESIGN

Non-randomised observational study of data derived from a randomised controlled study of anaesthetic technique for CEA.

METHODS

Data on heparin and protamine use and risk factors potentially influencing CEA outcome were collected prospectively. Stroke, death, MI, wound haematoma and re-operation rates were recorded following independent peer-review.

RESULTS

1513/2107 patients received heparin alone (H) and 594/2107 had heparin reversed with protamine (H+P). Risk factors for outcome were similar in both groups. The frequency of outcome events (H v H+P) were: stroke: 67/1513 (4.4%) v 17/594 (2.9%), p=0.098; non stroke or MI death: 10/1513 (0.7%) v 5/594 (0.8%), p=0.657; MI: 6/1513 (0.4%) v 3/594 (0.5%), p=0.718; haematoma: 157/1513 (10.4%) v 44/594 (7.4%), p=0.037; re-operation: 51/1380 (3.7%) v 18/565 (3.2%), p=0.581.

CONCLUSIONS

These results show a non-significant increase in stroke rate in patients receiving heparin alone refuting suggestions that protamine is harmful. Conversely post-operative haematoma was more frequent when protamine was withheld but re-operation rates were no different. Thus protamine use appears safe and should remain a matter for individual surgeon preference.

Carotid endarterectomy

Carotid endarterectomy (CEA) is performed to prevent embolic stroke in patients with atheromatous disease at the carotid bifurcation. There is now substantial evidence to support early operation in symptomatic patients, ideally within 2 weeks of the last neurological symptoms. Thus, the anaesthetist may be faced with a high risk patient in whom there has been limited time for preoperative preparation. The operation may be performed under local or general anaesthesia. The advantages and disadvantages of both are explored in this review. Carotid shunting may offer a degree of cerebral protection, but carries its own risks and has not been proved to reduce morbidity and mortality. The use of carotid shunts is based on clinical judgement, awake neurological monitoring, and the use of monitors of cerebral perfusion. There is no ideal monitor of cerebral perfusion in the patient receiving general anaesthesia. Both the intraoperative and postoperative periods may be witness to dramatic haemodynamic changes that may compromise the cerebral or myocardial circulations. In particular, postoperative hypotension may compromise both myocardial and cerebral perfusion, and severe hypertension can cause cerebral hyperperfusion. There is as yet limited evidence to guide the management of these problems. In summary, CEA can yield significant benefit, but those with the most to gain from the operation also present the greatest challenge to the anaesthetist.