Role of Activated Clotting Times in Carotid Stenting with Filter Protection

2003 ◽  
Vol 16 (1) ◽  
pp. 87-91
Author(s):  
L. Castellan ◽  
F. Causin ◽  
V. Pinna ◽  
M. Marchi ◽  
D. Danieli ◽  
...  
Keyword(s):  
Significant Proportion ◽  
Anticoagulation Therapy ◽  
Carotid Stenting ◽  
Statistical Correlation ◽  
Clotting Time ◽  
Activated Clotting Time ◽  
Heparin Anticoagulation ◽  
Distal Protection ◽  
Angiographic Findings

To evaluate the role of anticoagulation therapy in carotid stenting with filter devices, we compared the activated clotting times (ACT) to angiographic filter patency and to the materials found inside the filters. 29 endovascular treatments with filter cerebral protection in 27 patients affected by symptomatic internal carotid stenosis > 70% were considered. Angiographic findings, ACT and histopathologic specimens were recorded and statistically correlated. Satisfactory dilatation of the stenosis was always achieved with a complication rate of 3%. During the procedure nine filters caused temporary flow impairment. Histopathologic examination demonstrated material inside the filters in 86% of cases but this material was fibrin alone in 38% and plaque debris in 48%. Significant statistical correlation (p = 0.009) was found between low activated clotting time and occlusion of the filter. Distal protection filters can collect plaque fragments occurring during carotid stenting. A significant proportion of the debris found in the filters consisted of thrombotic material. Monitoring of heparin anticoagulation is recommended to prevent filter occlusion.

Variability of Activated Clotting Time by Site of Sample Draw During Percutaneous Coronary Intervention: A Prospective Single-Center Study

Angiology ◽  
2021 ◽  
pp. 000331972199223
Author(s):  
Jacqueline H. Morris ◽  
Junsoo Alex Lee ◽  
Scott McNitt ◽  
Ilan Goldenberg ◽  
Craig R. Narins
Keyword(s):  
Percutaneous Coronary Intervention ◽  
Unfractionated Heparin ◽  
Anticoagulation Therapy ◽  
Coronary Intervention ◽  
Clotting Time ◽  
Access Sheath ◽  
Arterial Blood ◽  
Activated Clotting Time ◽  
Guide Catheter ◽  
Percutaneous Coronary

The activated clotting time (ACT) assay is used to monitor and titrate anticoagulation therapy with unfractionated heparin during percutaneous coronary intervention (PCI). Observations at our institution suggested a considerable difference between ACT values drawn from varying arterial sites, prompting the current study. Patients undergoing PCI with unfractionated heparin therapy were prospectively enrolled. Simultaneous arterial blood samples were drawn from the access sheath and the coronary guide catheter. Differences between Hemochron ACT values were determined, and potential interactions with clinical variables were analyzed. Immediately postprocedure, the simultaneous mean guide and sheath ACTs were 327 ± 62 seconds and 257 ± 44 seconds, respectively, with a mean difference of 70 ± 60 seconds (P < .001). Nearly all (90%) ACT values obtained via the guide catheter were higher than the concurrent ACT drawn from the sheath. Logistic regression analysis demonstrated that lower weight-adjusted heparin doses and absence of diabetes were associated with a greater difference between the ACT values. We conclude that the ACT value is substantially greater when assessed via the guide catheter versus the access sheath. Although the biological mechanisms require further study, this difference should be considered when managing anticoagulation during PCI and when reporting ACT as part of research protocols.

scholarly journals Point-of-Care Measurement of Activated Clotting Time for Cardiac Surgery as measured by the Hemochron Signature Eliteand the Abbott i-STAT: Agreement, Concordance, and Clinical Reliability

2019 ◽  
Author(s):  
Daniel Dirkmann ◽  
Elisabeth Nagy ◽  
Martin Walter Britten ◽  
Juergen Peters
Keyword(s):  
Cardiac Surgery ◽  
Linear Correlation ◽  
Point Of Care ◽  
Clotting Time ◽  
Cohen’S Kappa ◽  
Cohen's Kappa ◽  
Activated Clotting Time ◽  
Target Values ◽  
Heparin Anticoagulation ◽  
Parallel Measurements

Abstract Background: Since inadequate heparin anticoagulation and insufficient reversal can result in complications during cardiopulmonary bypass (CPB) surgery, heparin anticoagulation monitoring by point-of-care (POC) activated clotting time (ACT) measurements is essential for CPB initiation, maintainance, and anticoagulant reversal. However, concerns exist regarding reproducibility of ACT assays and comparability of devices. Methods: We evaluated the agreement of ACT assays using four parallel measurements performed on two commonly used devices each (i.e., two Hemochron Signature Elite (Hemochron) and two Abbott i-STAT (i-STAT) devices, respectively). Blood samples from 30 patients undergoing cardiac surgery on CPB were assayed at specified steps (baseline, after heparin administration, after protamine administration) with four parallel measurements (two of each device type) using commercial Kaolin activated assays provided by the respective manufactures. Measurements were compared between identical and different device types using linear regression, Bland-Altman analyses, and calculation of Cohen’s kappa coefficient. Results: Parallel i-STAT ACTs demonstrated a good linear correlation (r=0.985). Bias, as determined by Bland-Altman analysis, was low (-3.8s; 95% limits of agreement (LOA): -77.8 -70.2s), and Cohen’s Kappa demonstrated good agreement (kappa=0.809). Hemochron derived ACTs demonstrated worse linear correlation (r=0.782), larger bias with considerably broader LOA (-13.14s; 95%LOA:-316.3-290s), and lesser concordance between parallel assays (kappa=0.554). Although demonstrating a fair linear correlation (r=0.815), parallel measurements on different ACT-devices showed large bias (-20s; 95% LOA: -290-250s) and little concordance (kappa=0.368). Overall, disconcordant results according to clinically predefined target values were more frequent with the Hemochron than i-STAT. Furthermore, while discrepancies in ACT between two parallel iSTAT assays showed little or no clinical relevance, deviations from parallel Hemochron assays and iSTAT versus Hemochron measurements revealed marked and sometimes clinically critical deviations. Conclusion: Currently used ACT point-of-care devices cannot be used interchangeably. Furthermore, our data question the reliability of the Hemochron in assessing adequacy of heparin anticoagulation monitoring for CPB.

Assessment of Heparin Anticoagulation Measured Using i-STAT and Hemochron Activated Clotting Time

2018 ◽  
Vol 32 (4) ◽  
pp. 1603-1608 ◽  
Author(s):  
Andrew Maslow ◽  
Alison Chambers ◽  
Tracey Cheves ◽  
Joseph Sweeney
Keyword(s):  
Clotting Time ◽  
Activated Clotting Time ◽  
Heparin Anticoagulation

A comparative analysis of four activated clotting time measurement devices in cardiac surgery with cardiopulmonary bypass

Perfusion ◽  
2020 ◽  
pp. 026765912094935
Author(s):  
Han Li ◽  
Cyril Serrick ◽  
Vivek Rao ◽  
Paul M Yip
Keyword(s):  
Cardiac Surgery ◽  
Cardiopulmonary Bypass ◽  
System Analysis ◽  
Point Of Care ◽  
Measurement Range ◽  
Medical Decision ◽  
Clotting Time ◽  
Activated Clotting Time ◽  
Decision Points ◽  
Heparin Anticoagulation

Background: In cardiac surgery on cardiopulmonary bypass (CPB), heparin anticoagulation is monitored by point-of-care measurement of activated clotting time (ACT). The objective of this study was to compare four ACT systems in cardiac surgery in terms of their reproducibility, agreement and potential clinical impact at relevant medical decision points. Methods: The study included 40 cardiac surgery patients. Samples were taken at five time points before (T1), after heparinization for CPB (T2, T3, T4), and after heparin reversal (T5). The reproducibility, correlation, and differences in ACT values were assessed with two devices from each of the four ACT systems: Instrumentation Laboratory Hemochron Elite (Hmch), Medtronic HMS Plus (HMS), Abbott i-STAT, and Helena Abrazo. Subrange analyses were performed for low ACT values (results from T1, T5) and high ACT values (results from T2, T3, T4). Results: Within-system analysis showed strong linear correlation between paired measurements (R = 0.968-0.993). However, Hmch showed poorer reproducibility with highest proportion of values that exceed a difference of 10% and highest overall standard error of 74 seconds across the measurement range compared to that of the others (range 39-47 seconds, respectively). For inter-system comparison, using Hmch as reference, ACTs were strongly correlated as follows: HMS (R = 0.938), i-STAT (R = 0.911), and Abrazo (R = 0.911). Agreement analysis in the high ACT range showed HMS tended to have higher ACT values with +11% bias over Hmch, whereas i-STAT (–8% bias) and Abrazo (–13% bias) tended to underestimate. Post-protamine ACT results were dependent on device type where Hmch yielded highest post-protamine ACT (+13% higher than baseline) compared to –16% for HMS, –10% for iSTAT and 0% for Abrazo. Conclusions: Each device had individual reproducibility and biases, which may impact peri-operative heparin management. Careful validation must be undertaken when adopting a different method as decision limits would be affected. Clinicians should also be cautious using ACT as the only indicator for full heparin reversal.

scholarly journals Point-of-Care Measurement of Activated Clotting Time for Cardiac Surgery as measured by the Hemochron Signature Eliteand the Abbott i-STAT: Agreement, Concordance, and Clinical Reliability

2019 ◽  
Author(s):  
Daniel Dirkmann ◽  
Elisabeth Nagy ◽  
Martin Walter Britten ◽  
Juergen Peters
Keyword(s):  
Cardiac Surgery ◽  
Linear Correlation ◽  
Point Of Care ◽  
Clotting Time ◽  
Cohen’S Kappa ◽  
Cohen's Kappa ◽  
Activated Clotting Time ◽  
Target Values ◽  
Heparin Anticoagulation ◽  
Parallel Measurements

Abstract Background: Since inadequate heparin anticoagulation and insufficient reversal can result in complications during cardiopulmonary bypass (CPB) surgery, heparin anticoagulation monitoring by point-of-care (POC) activated clotting time (ACT) measurements is essential for CPB initiation, maintainance, and anticoagulant reversal. However, concerns exist regarding reproducibility of ACT assays and comparability of devices. Methods: We evaluated the agreement of ACT assays using four parallel measurements performed on two commonly used devices each (i.e., two Hemochron Signature Elite (Hemochron) and two Abbott i-STAT (i-STAT) devices, respectively). Blood samples from 30 patients undergoing cardiac surgery on CPB were assayed at specified steps (baseline, after heparin administration, after protamine administration) with four parallel measurements (two of each device type) using commercial Kaolin activated assays provided by the respective manufactures. Measurements were compared between identical and different device types using linear regression, Bland-Altman analyses, and calculation of Cohen’s kappa coefficient. Results: Parallel i-STAT ACTs demonstrated a good linear correlation (r=0.985). Bias, as determined by Bland-Altman analysis, was low (-3.8s; 95% limits of agreement (LOA): -77.8 -70.2s), and Cohen’s Kappa demonstrated good agreement (kappa=0.809). Hemochron derived ACTs demonstrated worse linear correlation (r=0.782), larger bias with considerably broader LOA (-13.14s; 95%LOA:-316.3-290s), and lesser concordance between parallel assays (kappa=0.554). Although demonstrating a fair linear correlation (r=0.815), parallel measurements on different ACT-devices showed large bias (-20s; 95% LOA: -290-250s) and little concordance (kappa=0.368). Overall, disconcordant results according to clinically predefined target values were more frequent with the Hemochron than i-STAT. Furthermore, while discrepancies in ACT between two parallel iSTAT assays showed little or no clinical relevance, deviations from parallel Hemochron assays and iSTAT versus Hemochron measurements revealed marked and sometimes clinically critical deviations. Conclusion: Currently used ACT point-of-care devices cannot be used interchangeably. Furthermore, our data question the reliability of the Hemochron in assessing adequacy of heparin anticoagulation monitoring for CPB.

Nafamstat mesilate attenuates pulmonary hypertension in heparin-protamine reactions

1989 ◽  
Vol 67 (4) ◽  
pp. 1463-1471 ◽  
Author(s):  
E. Kreil ◽  
G. Montalescot ◽  
E. Greene ◽  
C. Fitzgibbon ◽  
D. Robinson ◽  
...  
Keyword(s):  
Complement Activation ◽  
Pulmonary Arterial Pressure ◽  
Fold Increase ◽  
Complement Pathway ◽  
Clotting Time ◽  
Pulmonary Vasoconstriction ◽  
Activated Clotting Time ◽  
Heparin Anticoagulation ◽  
Pulmonary Arterial ◽  
Arterial Plasma

Rapid protamine reversal of heparin anticoagulation in awake sheep caused, after 1 min, a approximately 15-fold increase of arterial plasma thromboxane B2 (TxB2) levels, a 4-fold rise of pulmonary vascular resistance (PVR), a 2-fold rise of pulmonary arterial pressure, and after 3 min, a 2-fold rise of ovine arterial plasma complement C3a levels (P less than 0.05). Infusion of nafamstat mesilate (FUT-175), a protease and complement pathway inhibitor, before protamine reduced these increases by approximately 60–90% (P less than 0.05). FUT-175 did not modify heparin + protamine-induced leukopenia, suggesting that FUT-175 incompletely blocked C5a production. We also learned that infusing protamine first and heparin 5 min later did not increase either plasma C3a or TxB2 levels or PVR while the activated clotting time increased only minimally. Thus, in awake sheep, the sequence of heparin and protamine infusion influences complement activation and pulmonary vasoconstriction. FUT-175 pretreatment reduces thromboxane release and pulmonary vasoconstriction probably by limiting complement activation.

Monitoring of low molecular weight heparin anticoagulation during haemodialysis with a Sonoclot Analyzer

Perfusion ◽  
2010 ◽  
Vol 25 (4) ◽  
pp. 191-196 ◽  
Author(s):  
Ulf Schött ◽  
Lars Göran Nilsson ◽  
Marcus Broman ◽  
Martin Engström
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight Heparin ◽  
Progressive Increase ◽  
Low Molecular Weight ◽  
Fibrin Deposition ◽  
Clotting Time ◽  
Activated Clotting Time ◽  
Half Dose ◽  
Heparin Anticoagulation

Objectives: Sonoclot was used in this study to monitor low molecular weight heparin (LMWH) during haemodialysis. Material and Methods: Two different intravenous doses (standard / half-dose) of dalteparin were studied in eight patients. Blood was sampled for coagulation analyses with Sonoclot, thrombin-antithrombin (TAT) and anti-Xa. A visual fibrin deposition score (VFS) in the venous drip chamber was also evaluated. Results: All patients completed their dialysis. There was a progressive increase in TAT levels, which correlated to the dalteparin dose. Significant differences (p<0.05) were found for TAT, VFS and Sonoclot celite-activated clotting time (SonACT) between the different LMWH dosages. TAT and Sonoclot correlated to each other, but not to the VFS. SonACT was significantly increased at two hours, with the high dalteparin dose compared to the lower dose. Conclusion: Both Sonoclot and TAT failed to predict the VFS. No patient had any clinical clotting events and all dialyses were completed successfully.

scholarly journals The role of the activated clotting time in heparin administration and neutralization for cardiopulmonary bypass

1983 ◽  
Vol 85 (2) ◽  
pp. 174-185 ◽  
Author(s):  
Rick A. Esposito ◽  
Alfred T. Culliford ◽  
Stephen B. Colvin ◽  
Stephen J. Thomas ◽  
Henriette Lackner ◽  
...  
Keyword(s):  
Cardiopulmonary Bypass ◽  
Clotting Time ◽  
Activated Clotting Time ◽  
Heparin Administration
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