Editor's Choice – Protamine Reduces Serious Bleeding Complications Associated with Carotid Endarterectomy in Asymptomatic Patients without Increasing the Risk of Stroke, Myocardial Infarction, or Death in a Large National Analysis

The Utilization of Protamine during Peripheral Vascular Interventions in the VQI

BACKGROUND

Protamine administration was shown to reduce bleeding after carotid surgery but the role of protamine during peripheral vascular interventions (PVIs) remains unknown. This study evaluates the trend and outcomes of protamine use in the Vascular Quality Initiative (VQI). Our hypothesis is that the use of protamine is associated with decreased bleeding after PVI.

METHODS

Patients undergoing elective PVI in the VQI (2016-2020) for peripheral arterial disease were reviewed and the utilization trend for protamine was described. The characteristics of patients undergoing PVI with and without protamine use were compared. After propensity score matching based on the patient's comorbidities, access site, and procedural characteristics, the perioperative outcomes of both groups were compared using multivariable Poisson regression to estimate adjusted rate ratios (aRRs) and 95% confidence intervals (95% CIs).

RESULTS

The total number of patients was 131,618 and patients who received protamine constituted 29.8% of the sample (N = 38,191). After propensity matching, the total number of patients was 94,582, and patients who received protamine constituted 28.8% of the sample (N = 27,275). Protamine use significantly increased during the study period from 5.2 to 22.9%. Before propensity score matching, patients who received protamine were more likely to be white (79% vs. 76.8, P ≤ 0.001), smokers (80.5% vs. 78.5%, P ≤ 0.001), with medical comorbidities including hypertension (88.9% vs. 88.5%, P = 0.074), congestive heart failure (20.5% vs. 19.8%, P = 0.006), and chronic obstructive pulmonary disease (28.2% vs. 26.5%). They were also more likely to be on perioperative medications such as P2Y12 inhibitors (44.3% vs. 45, P = 0.013%) and statin (77.4% vs. 76.5%, P = 0.001) compared to patients who did not receive protamine. After propensity matching, there were no significant differences between the 2 groups. There was a significant decrease in bleeding during procedures where protamine was administered compared to no protamine (2.0% vs. 2.2%) (aRR, 0.89 [95% CI 0.80, 0.98]). Protamine was more likely to be given in procedures complicated by perforation (0.8% vs. 0.5%) (aRR, 1.48 [95% CI 1.24, 1.76]) and less likely to be given during procedures with distal embolization (0.4% vs. 0.7%) (aRR, 0.59 [95% CI 0.49, 0.73]). However, patients receiving protamine had significantly higher cardiac complications (1.4% vs. 1.1%) (aRR, 1.27 [95% CI 1.12, 1.43]). There was no significant difference in mortality between the 2 groups.

CONCLUSIONS

Protamine use is associated with decreased perioperative bleeding but increased cardiac complications. Protamine should be selectively administered to patients at high risk of bleeding during PVI.

Interventions in Carotid Artery Surgery: An Overview of Current Management and Future Implications

Atherosclerotic carotid artery disease has been well studied over the last half-century by multiple randomized controlled trials attempting to elucidate the appropriate modality of therapy for this disease process. Surgical techniques have evolved from carotid artery endarterectomy and transfemoral carotid artery stenting to the development of hybrid techniques in transcarotid artery revascularization. In this article, the authors provide a review of the available literature regarding operative and medical management of carotid artery disease.

Prognostic Factors for Postoperative Bleeding Complications and Prolonged Intensive Care after Percutaneous Hepatic Chemosaturation Procedures with Melphalan

Percutaneous hepatic melphalan perfusion (chemosaturation) in patients with liver metastases is known to be associated with procedure-related hemodynamic depression and coagulation impairment, which may cause bleeding complications and/or a prolonged intensive care unit length of stay (ICU LOS). We retrospectively analyzed possible predictive factors for bleeding complications and an ICU LOS > 1 d in a cohort of 31 patients undergoing 90 chemosaturation procedures. Using a multivariable mixed-model approach, we identified the amount of perioperative fluid volume (OR 12.0, 95% CI 2.3-60.0, p = 0.003) and protamine (OR 0.065, 95% CI 0.007-0.55, p = 0.012) to be associated with bleeding complications. Furthermore, the amount of perioperative fluid volume was associated with an ICU LOS > 1 d (OR 5.2, 95% CI 1.4-19.0, p = 0.011). Heparin dosage, melphalan dosage, extracorporeal circulation time, and noradrenaline dosage had no significant effects on outcomes. Protamine use was not associated with anaphylactic or thromboembolic complications. Despite the limited sample size, these results suggest a restrictive perioperative fluid regime to be beneficial, and support the use of protamine for heparin reversal after chemosaturation procedures. Further prospective randomized trials are needed to confirm these findings.

Vascular Quality Initiative assessment of compliance with Society for Vascular Surgery clinical practice guidelines on the management of extracranial cerebrovascular disease

OBJECTIVES

Compliance with Society for Vascular Surgery (SVS) clinical practice guidelines (CPGs) is associated with improved outcomes for the treatment of abdominal aortic aneurysm, but this has not been assessed for carotid artery disease. The Vascular Quality Initiative (VQI) registry was used to examine compliance with the SVS CPGs for the management of extracranial cerebrovascular disease and its impact on outcomes.

METHODS

The 2021 SVS extracranial cerebrovascular disease CPGs were reviewed for evaluation by VQI data. Compliance rates by the center and provider were calculated, and the impact of compliance on outcomes was assessed using logistic regression with inverse probability-weighted risk adjustment for each CPG recommendation, allowing for clustering by the center. Our primary outcome was a composite end point of in-hospital stroke/death. As a secondary analysis, compliance with the 2021 SVS carotid implementation document recommendations and associated outcomes were also assessed.

RESULTS

Of the 11 carotid CPG recommendations, 4 (36%) could be evaluated using VQI registry data. Median center-specific CPG compliance ranged from 38% to 95%, and median provider-specific compliance ranged from 36% to 100%. After adjustment, compliance with 2 of the recommendations was associated with lower rates of in-hospital stroke/death: first, the use of best medical therapy (antiplatelet and statin therapy) in low/standard surgical risk patients undergoing carotid endarterectomy for >70% asymptomatic stenosis (event rate in compliant vs noncompliant cases 0.59% vs 1.3%; adjusted odds ratio: 0.44, 95% confidence interval: 0.29-0.66); and second, carotid endarterectomy over transfemoral carotid artery stenting in low/standard surgical risk patients with >50% symptomatic stenosis (1.9% vs 3.4%; adjusted odds ratio: 0.55, 95% confidence interval: 0.43-0.71). Of the 132 implementation document recommendations, only 10 (7.6%) could be assessed using VQI data, with median center- and provider-specific compliance rates ranging from 67% to 100%. The impact of compliance on outcomes could only be assessed for 6 (4.5%) of these recommendations, and compliance with all 6 recommendations was associated with lower stroke/death.

CONCLUSIONS

Few SVS recommendations could be assessed in the VQI because of incongruity between the recommendations and the VQI data variables collected. Although guideline compliance was extremely variable among VQI centers and providers, compliance with most of these recommendations was associated with improved outcomes after carotid revascularization. This finding confirms the value of guideline compliance, which should be encouraged for centers and providers. Optimization of VQI data to promote evaluation of guideline compliance and distribution of these findings to VQI centers and providers will help facilitate quality improvement efforts in the care of vascular patients.

Protamine use in transcarotid arterial revascularization

OBJECTIVE

The literature suggests that heparin reversal with protamine in transcarotid arterial revascularization (TCAR) decreases postoperative bleeding complications without an increase in stroke or death. However, the dosing of protamine in TCAR has not yet been evaluated. We aimed to evaluate our experience with intraoperative heparin reversal with protamine.

METHODS

This was a single-center, retrospective, observational study that evaluated the heparin and protamine doses used during TCAR. All adult patients who underwent TCAR between 9/1/2019 and 4/2/2021 were included. Demographic data was obtained from the Vascular Quality Initiative and protamine/heparin doses were obtained from a chart review. Multivariate logistic regression models were used to assess the association between the protamine/heparin dose ratio and other variables.

RESULTS

Sixty-two patients were included. The average protamine/heparin dose ratio used was 0.96 ± 0.12 mg/U; seven had a ratio less than 0.8 mg/U, and one was greater than 1.2 mg/U. Two patients experienced bleeding complications, which were managed non-operatively. No patient with a protamine/heparin ratio greater than 0.8 mg/U had postoperative bleeding. Postoperative bradycardia was observed in 32.3% of patients and hypotension in 35%, with 19% requiring vasopressors. No relationship was identified between the protamine/heparin ratio and bleeding, bradycardia, or hypotension. No 30-day myocardial infarction, stroke or death occurred.

CONCLUSIONS

We identified a near 1:1 ratio of a protamine/heparin dosing regimen for the reversal of heparin during TCAR, with postoperative bleeding complications similar to those reported in the literature. However, patients who received a lower protamine/heparin ratio did not experience bleeding complications. In the era of protamine shortages, a future larger-scale study is needed to evaluate the impact of a lower protamine dose on postoperative complications.

Unplanned readmission after carotid stenting versus endarterectomy: analysis of the United States Nationwide Readmissions Database

BACKGROUND

Hospital readmissions are costly and reflect negatively on care delivered.

OBJECTIVE

To have a better understanding of unplanned readmissions after carotid revascularization, which might help to prevent them.

METHODS

The Nationwide Readmissions Database was used to determine rates and reasons for unplanned readmission following carotid endarterectomy (CEA) and carotid artery stenting (CAS). Trends were assessed by annual percent change, modified Poisson regression was used to estimate risk ratios (RR) for readmission, and propensity scores were used to match cohorts.

RESULTS

Analysis yielded 522 040 asymptomatic and 55 485 symptomatic admissions for carotid revascularization between 2010 and 2015. Higher 30-day readmission rates were noted after CAS versus CEA in both symptomatic (9.1% vs 7.7%, p<0.001) and asymptomatic (6.8% vs 5.7%, p<0.001) patients. Readmission rates trended lower over time, significantly so for 90-day readmissions in symptomatic patients undergoing CEA. The most common cause for 30-day readmission was stroke in both symptomatic (5.5%) and asymptomatic (3.9%) patients. Factors associated with a higher risk of readmission included age over 80; male gender; Medicaid health insurance; and increases in severity of illness, mortality risk, and comorbidity indices. Analysis of matched cohorts showed that CAS had higher readmission than CEA (RR=1.14 (95% CI 1.06 to 1.22); p<0.001) only in asymptomatic patients. Adverse events during initial admission which predicted 30-day readmission included acute renal failure and acute respiratory failure in asymptomatic patients; hematoma and cardiac events were additional predictive adverse events in symptomatic patients.

CONCLUSIONS

Readmission is not uncommon after carotid revascularization, occurs more often after CAS, and is predicted by baseline factors and by preventable adverse events at initial admission.

Effect of Chronic Antiplatelet and Anticoagulant Medication in Neck Haematoma and Perioperative Outomes After Carotid Endarterectomy

OBJECTIVES

A retrospective analysis of neck haematoma, stroke and mortality after symptomatic and asymptomatic carotid endarterectomy (CEA) was conducted, in order to determine the most appropriate perioperative medication for these patients. Thirty-day outcomes of moderate and severe neck bleeding were also investigated.

METHODS

Patients undergoing CEA in a Vascular Surgery department were analysed (2015-2019). Pre-procedure antithrombotic medication (from the 5-days prior to surgery) was identified. End point predictors were identified by univariate and multivariable analyses and adjusted for confounders.

RESULTS

A total of 304 CEA were included. Almost half of the included patients (49.67%) were under low-dose aspirin, 17.55% other single antiplatelet agent, 12.59% dual antiplatelet therapy, 8.61% anticoagulation and 10.92% no antithrombotic therapy. There was 8.22% rate of important haematoma, including 4.93% severe (requiring surgical exploration) hematomas and a 30-day all-stroke incidence of 2.94% in symptomatic and 1.79% asymptomatic patients (p=.51). When compared to aspirin, severe haematoma was more prevalent with single clopidogrel or triflusal (RR 4.25, p=.11), dual antiplatelet group (RR 11.84, p=.002) and anticoagulation (RR 8.604, p=.02). Dual antiaggregation and anticoagulation did not confer post-operative stroke protection compared to single aspirin in either symptomatic or asymptomatic patients. Non-significant higher intra-hospital mortality was noted in no medication, dual antiplatelet and anticoagulation groups in contrast to aspirin. Severe neck bleeding was associated with increased congestive heart failure (9.26-fold, p=.03) and longer hospital stay (11.20±24.69 days versus 3.18±4.79 with no bleeding, p<.001), with a tendency for higher hospital readmission at 30-days (4.66-fold, p=.13). Mortality and stroke rates were similar.

CONCLUSIONS

Double antiaggregation and anticoagulation did not confer better perioperative outcomes after elective CEA in our study. These regimens were associated with increased risk of neck haematoma, especially severe bleeding, with similar rates of neurologic events in both symptomatic and asymptomatic patients and no mortality benefit. Monotherapy with aspirin appears to be the safest perioperative antithrombotic regimen for elective CEA.

Transcarotid Artery Revascularization: Is It Better than Carotid Endarterectomy?

Transcarotid artery revascularization (TCAR) is a novel carotid stenting method that avoids the manipulation of the aortic arch and uses a flow-reversal neuroprotection system that effectively reduces the risk of embolic events during carotid intervention. Studies have shown a lower risk of stroke or death compared with the transfemoral carotid stenting approach, and an equivalent risk of stroke or death compared with traditional carotid endarterectomy. TCAR has added benefits of lower risk of myocardial infarction, cranial nerve injuries, and shorter operative times compared with endarterectomy. TCAR has become widely adopted by vascular surgeons in the United States for the treatment of patients with high-risk medical comorbidities and those with challenging surgical anatomy.

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 &lt; 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.

Symptom Status of Patients Undergoing Carotid Endarterectomy in Canada and United States

BACKGROUND

Previous studies have demonstrated significant geographic variations in the management of carotid artery stenosis despite standard guidelines. To further characterize these practice variations, we assessed differences in patient selection, operative technique, and outcomes for carotid endarterectomy (CEA) in Canada vs. United States.

METHODS

The Vascular Quality Initiative (VQI) was used to identify all patients who underwent CEA between 2010 and 2019 in Canada and United States. Demographic, clinical, and procedural characteristics were recorded and differences between countries were assessed using independent t-test and chi-square test. The primary outcome was the percentage of CEA performed for asymptomatic versus symptomatic disease. The secondary outcomes were 30-day and long-term stroke or death. Associations between country and outcomes were assessed using univariate/multivariate logistic regression and Cox proportional hazards analysis.

RESULTS

During the study period, 131,411 US patients and 701 Canadian patients underwent CEA in VQI sites. Patients from the US were older with more comorbidities including hypertension, diabetes, congestive heart failure, and chronic kidney disease. The use of a shunt, patch, drain, or protamine was less common in the US. Most patients had 70 - 99% stenosis, with no difference between regions. The percentage of CEA performed for asymptomatic disease was significantly higher in the US even after adjusting for demographic, clinical, and procedural characteristics (72.4% vs. 30.7%, adjusted OR 3.91 [95% CI 3.21 - 4.78], p < 0.001). Thirty-day stroke/death was low (1.8% vs. 1.9%) and 1-year stroke/death was similar between groups (HR 0.98 [95% CI 0.69 - 1.39], P = 0.89). The similarities in 1-year stroke/death persisted in asymptomatic patients (HR 0.70 [95% CI 0.37 - 1.30], P = 0.26) and symptomatic patients (HR 1.14 [95% CI 0.74 - 1.73], P = 0.56).

CONCLUSIONS

There are significant variations in CEA practice between Canada and US. In particular, most US patients are treated for asymptomatic disease, whereas most Canadian patients are treated for symptomatic disease. Furthermore, adjunctive procedures including shunting, patch use, and protamine administration are performed less commonly in the US. Despite these differences, perioperative and 1-year stroke/death rates are similar between countries. Future studies should investigate reasons for these variations and quality improvement projects are needed to standardize care.