Variability in Contemporary Heparin Prescription and Activated Clotting Time Monitoring During Percutaneous Coronary Intervention: Call for Up-To-Date Evidence-Based Guidelines

BACKGROUND

Unfractionated heparin (UFH) is the preferred anticoagulant agent in percutaneous coronary intervention (PCI) procedures for minimising the risk of thrombotic complications. Because of the narrow therapeutic range of UFH, some society guidelines have advocated the use of the activated clotting time (ACT) test to monitor anticoagulation intensity during PCI to reduce thrombotic and bleeding complications. We aimed to assess the current practice of UFH prescription and its monitoring in Australia and New Zealand (ANZ).

METHOD

We conducted an anonymous voluntary cross-sectional survey of interventional cardiologists (ICs) who were members of the Cardiac Society of Australia and New Zealand in 2022. The survey included 10 questions pertaining to the current practice of anticoagulation during PCI.

RESULTS

Of 430 ICs surveyed, 148 responded (response rate, 34.4%). Most ICs (84.4%) prescribed 70-100 IU/kg of UFH for PCI. Over half of ICs (58.7%) routinely measured ACT during PCI, whereas only 22.2% routinely measured ACT after PCI to guide additional UFH prescription. Among ICs who prescribed additional UFH, approximately half (48%) aimed for ACT ≥250 seconds. Factors that influenced post-PCI UFH prescription included vascular access site and concomitant antiplatelet or anticoagulant therapy.

CONCLUSIONS

The contemporary practice of UFH prescription during PCI and ACT monitoring in ANZ is variable and based on outdated evidence preceding current drug-eluting stents, antiplatelet therapies, and radial-first practice. Current society guideline recommendations lack clarity and agreement, reflecting the quality of the available evidence. Up-to-date clinical trials evaluating UFH prescription and ACT monitoring are needed to optimise clinical outcomes in contemporary PCI procedures.

Safety and efficacy of periprocedural antithrombotics in patients with successful reperfusion after endovascular stroke treatment

OBJECTIVES

We aimed to evaluate whether the overall harmful effect of periprocedural treatment with aspirin or heparin during endovascular stroke treatment is different in patients with a successful reperfusion after the procedure.

MATERIALS AND METHODS

We performed a post-hoc analysis of the MR CLEAN-MED trial, including adult patients with a large vessel occlusion in the anterior circulation eligible for endovascular treatment (EVT). In this trial, patients were randomized for periprocedural intravenous treatment with aspirin or no aspirin (1:1 ratio), and for moderate-dose unfractionated heparin, low-dose unfractionated heparin or no unfractionated heparin (1:1:1 ratio). We tested for interaction between the post-EVT extended thrombolysis in cerebral infarction (eTICI) score and treatment with periprocedural medication with multivariable regression analyses. The primary outcome was the modified Rankin Scale score at 90 days. Secondary outcomes were final infarct volume, intracranial hemorrhage, and symptomatic intracranial hemorrhage.

RESULTS

Of 534 included patients, 93 (17%) had a post-EVT eTICI score of 0-2a, 115 (22%) a score of 2b, 73 (14%) a score of 2c, and 253 (47%) a score of 3. For both aspirin and heparin, we found no interaction between post-EVT eTICI score and treatment on the modified Rankin Scale score (p=0.76 and p=0.47, respectively). We found an interaction between post-EVT eTICI score and treatment with heparin on the final infarct volume (p=0.01). Of note, this interaction showed a biologically implausible distribution over the subgroups.

CONCLUSIONS

The overall harmful effect of periprocedural aspirin and unfractionated heparin is not different in patients with a successful reperfusion after EVT.

A Factor XIa Inhibitor Engineered from Banded Krait Venom Toxin: Efficacy and Safety in Rodent Models of Arterial and Venous Thrombosis

Activated factor XI (FXIa) is an important antithrombotic drug target. Clinical and pre-clinical data have demonstrated that its inhibition attenuates thrombosis with minimal risk of excessive bleeding. We isolated Fasxiator from the venom of banded krait Bungarus fasciatus and subsequently engineered FasxiatorN17R,L19E, with improved affinity (Ki = 0.9 nM) and selectivity towards FXIa. Here, we assess the in vivo efficacy and bleeding risk of rFasxiatorN17R, L19E in pre-clinical animal models. Rats injected intravenously (i.v.) with bolus rFasxiatorN17R, L19E showed the specific in vivo attenuation of the intrinsic coagulation pathway, lasting for at least 60 min. We performed the in vivo dose-ranging experiments for rFasxiatorN17R, L19E as follows: FeCl3-induced carotid artery occlusion in rats (arterial thrombosis); inferior vena cava ligation in mice (venous thrombosis); tail bleeding time in both rats and mice (bleeding risk). Head-to-head comparisons were made using therapeutic dosages of unfractionated heparin (UFH) and low-molecular-weight heparin (LMWH) for arterial and venous thrombosis, respectively. In the arterial thrombosis model, 2 mg/kg i.v. rFasxiatorN17R,L19E achieved a similar antithrombotic efficacy to that of UFH, with >3-fold lower bleeding time. In the venous thrombosis model, the 10 mg/kg subcutaneous (s.c.) injection of rFasxiatorN17R,L19E achieved similar efficacy and bleeding levels to those of LMWH enoxaparin. Overall, rFasxiatorN17R,L19E represents a promising molecule for the development of FXIa-targeting anticoagulants.

Enhanced Thrombin Generation Is Associated with Worse Left Ventricular Scarring after ST-Segment Elevation Myocardial Infarction: A Cohort Study

Acute myocardial infarction (AMI) is associated with heightened thrombin generation. There are limited data relating to thrombin generation and left ventricular (LV) scarring and LV dilatation in post-MI LV remodeling. We studied 113 patients with ST-segment elevation myocardial infarction (STEMI) who had undergone primary percutaneous coronary intervention (PPCI) (n = 76) or pharmaco-invasive management (thrombolysis followed by early PCI, n = 37). Endogenous thrombin potential (ETP) was measured at baseline, 1 month and 6 months. Cardiovascular magnetic resonance imaging was performed at baseline and 6 months post-MI. Outcomes studied were an increase in scar change, which was defined as an increase in left ventricular infarct size of any magnitude detected by late gadolinium enhancement, adverse LV remodeling, defined as dilatation (increase) of left ventricular end-diastolic volume (LVEDV) by more than 20% and an increase in left ventricular ejection fraction (LVEF). The mean age was 55.19 ± 8.25 years and 91.2% were men. The baseline ETP was similar in the PPCI and pharmaco-invasive groups (1400.3 nM.min vs. 1334.1 nM.min, p = 0.473). Each 10-unit increase in baseline ETP was associated with a larger scar size (adjusted OR 1.020, 95% CI 1.002–1.037, p = 0.027). Baseline ETP was not associated with adverse LV remodeling or an increase in LVEF. There was no difference in scar size or adverse LV remodeling among patients undergoing PPCI vs. pharmaco-invasive management or patients receiving ticagrelor vs. clopidogrel. Enhanced thrombin generation after STEMI is associated with a subsequent increase in myocardial scarring but not LV dilatation or an increase in LVEF at 6 months post-MI.

P2Y12 Antagonists in Cardiovascular Disease—Finding the Best Balance Between Preventing Ischemic Events and Causing Bleeding

Dual antiplatelet therapy comprising of aspirin and oral P2Y₁₂ receptor antagonists are an established cornerstone of therapy in acute coronary syndromes and percutaneous coronary intervention. As a result, the platelet P2Y₁₂ receptor remains a key therapeutic target in cardiovascular medicine since pharmacological antagonists were first developed in the 1990’s. With a greater understanding of platelet biology and the role played by the P2Y₁₂ receptor in the amplification of platelet activation and thrombus formation, there has been progressive refinement in the development of P2Y₁₂ receptor antagonists with greater potency and consistency of antiplatelet effect. However, challenges remain in the utilization of these agents particularly in balancing the need for greater protection from ischemic events whilst minimizing the bleeding risk and present a real opportunity for the institution of individualized medicine. Future drug developments will provide clinicians with greater avenues to achieve this.

Safety and efficacy of aspirin, unfractionated heparin, both, or neither during endovascular stroke treatment (MR CLEAN-MED): an open-label, multicentre, randomised controlled trial

BACKGROUND

Aspirin and unfractionated heparin are often used during endovascular stroke treatment to improve reperfusion and outcomes. However, the effects and risks of anti-thrombotics for this indication are unknown. We therefore aimed to assess the safety and efficacy of intravenous aspirin, unfractionated heparin, both, or neither started during endovascular treatment in patients with ischaemic stroke.

METHODS

We did an open-label, multicentre, randomised controlled trial with a 2 × 3 factorial design in 15 centres in the Netherlands. We enrolled adult patients (ie, ≥18 years) with ischaemic stroke due to an intracranial large-vessel occlusion in the anterior circulation in whom endovascular treatment could be initiated within 6 h of symptom onset. Eligible patients had a score of 2 or more on the National Institutes of Health Stroke Scale, and a CT or MRI ruling out intracranial haemorrhage. Randomisation was done using a web-based procedure with permuted blocks and stratified by centre. Patients were randomly assigned (1:1) to receive either periprocedural intravenous aspirin (300 mg bolus) or no aspirin, and randomly assigned (1:1:1) to receive moderate-dose unfractionated heparin (5000 IU bolus followed by 1250 IU/h for 6 h), low-dose unfractionated heparin (5000 IU bolus followed by 500 IU/h for 6 h), or no unfractionated heparin. The primary outcome was the score on the modified Rankin Scale at 90 days. Symptomatic intracranial haemorrhage was the main safety outcome. Analyses were based on intention to treat, and treatment effects were expressed as odds ratios (ORs) or common ORs, with adjustment for baseline prognostic factors. This trial is registered with the International Standard Randomised Controlled Trial Number, ISRCTN76741621.

FINDINGS

Between Jan 22, 2018, and Jan 27, 2021, we randomly assigned 663 patients; of whom, 628 (95%) provided deferred consent or died before consent could be asked and were included in the modified intention-to-treat population. On Feb 4, 2021, after unblinding and analysis of the data, the trial steering committee permanently stopped patient recruitment and the trial was stopped for safety concerns. The risk of symptomatic intracranial haemorrhage was higher in patients allocated to receive aspirin than in those not receiving aspirin (43 [14%] of 310 vs 23 [7%] of 318; adjusted OR 1·95 [95% CI 1·13-3·35]) as well as in patients allocated to receive unfractionated heparin than in those not receiving unfractionated heparin (44 [13%] of 332 vs 22 [7%] of 296; 1·98 [1·14-3·46]). Both aspirin (adjusted common OR 0·91 [95% CI 0·69-1·21]) and unfractionated heparin (0·81 [0·61-1·08]) led to a non-significant shift towards worse modified Rankin Scale scores.

INTERPRETATION

Periprocedural intravenous aspirin and unfractionated heparin during endovascular stroke treatment are both associated with an increased risk of symptomatic intracranial haemorrhage without evidence for a beneficial effect on functional outcome.

FUNDING

The Collaboration for New Treatments of Acute Stroke consortium, the Brain Foundation Netherlands, the Ministry of Economic Affairs, Stryker, Medtronic, Cerenovus, and the Dutch Heart Foundation.

Bivalirudin Presents a Favorable Safety Profile Regarding Adverse Drug Reactions, Thrombocytopenia, and Bleeding in Chinese Patients With High Bleeding Risk Undergoing Percutaneous Coronary Intervention: A Prospective, Multi-Center, Intensive Monitoring Study

Background

This study aimed to comprehensively explore the occurrence and risk factors for adverse events (AEs) and adverse drug reactions (ADRs) (especially for thrombocytopenia and bleeding) in Chinese patients with high bleeding risk (older adults, or complicated with diabetes mellitus or renal function impairment) undergoing percutaneous coronary intervention (PCI) with bivalirudin as an anticoagulant.

Methods

A total of 1,226 patients with high bleeding risk who received PCI with bivalirudin as an anticoagulant from 27 Chinese medical centers were enrolled in this prospective, multi-center, intensive monitoring study. AEs, ADRs, thrombocytopenia, and bleeding were collected from admission to 72 h post-bivalirudin administration; subsequently, patients were followed up on the 30th day with the safety data collected as well.

Results

Adverse events were observed in 198 (16.2) patients, among which severe AEs occurred in 16 (1.3%) patients. Meanwhile, bivalirudin-related ADRs were reported in 66 (5.4%) patients, among which 5 (0.4%) patients experienced bivalirudin-related severe ADRs. Besides, thrombocytopenia and bleeding occurred in 45 (3.7%) and 19 (1.5%) patients, respectively. The subsequent multivariate logistic analysis revealed that age >75 years [p = 0.017, odds ratio (OR) = 1.856] and spontaneous coronary artery dissection (SCAD) (p = 0.030, OR = 2.022) were independently related to higher ADR risk; SCAD (p = 0.017, OR = 2.426) was independently correlated with higher thrombocytopenia risk, while radial artery access (p = 0.015, OR = 0.352) was independently correlated with lower thrombocytopenia risk; and the administration of bivalirudin preoperatively or intraoperatively (p = 0.013, OR = 5.097) was independently associated with higher bleeding risk.

Conclusion

Bivalirudin presents a favorable safety profile regarding ADRs, thrombocytopenia, and bleeding in Chinese patients with high bleeding risk undergoing PCI.

A One-pot-synthesized Double-layered Anticoagulant Hydrogel Tube

Extracorporeal membrane oxygenation(ECMO) has emerged as a viable treatment in severe cases of acute respiratory distress syndrome, acute respiratory failure, and adult respiratory distress syndrome. However, thromboembolic events stemming from the use of ECMO devices results in significant morbidity and mortality rates; the inner surface of the ECMO tubing comes into contact with the blood and can readily initiate coagulation. In addition, the tubing needs to be continually replaced due to thromboses on the inner tube wall, which not only increases the risk of infection but also the economic burden. Despite considerable effort, a surface modification strategy that effectively addresses these challenges has not yet been realized. In this study, we developed an integrated hollow core-shell-shell hydrogel tube of gelatin/alginate/acrylamide-bacterial nanocellulose(GAA) that meets the anticoagulant requirements for the inner tubing layer as well as the highly elastic soft material needed for the outer layer. Using static blood from healthy volunteers, we confirmed that the platelets or coagulation is not stimulated by the GAA tubing. Importantly, experiments with dynamic blood also demonstrated that the inner layer of the tubing does not elicit blood clotting. The one-pot-synthesized process may provide guidance for the design of anticoagulation tubes used clinically.

Electronic Supplementary Material

Supplementary material is available in the online version of this article at 10.1007/s40242-021-1267-3.

Assessing the external validity of the VALIDATE-SWEDEHEART trial

Aims:

The VALIDATE-SWEDEHEART trial was a registry-based randomized trial comparing bivalirudin and heparin in patients with acute myocardial infarction undergoing percutaneous coronary intervention. It showed no differences in mortality at 30 or 180 days. This study examines how well the trial population results may generalize to the population of all screened patients with fulfilled inclusion criteria in regard to mortality at 30 and 180 days.

Methods:

The standardized difference in the mean propensity score for trial inclusion between trial population and the screened not-enrolled with fulfilled inclusion criteria was calculated as a metric of similarity. Propensity scores were then used in an inverse-probability weighted Cox regression analysis using the trial population only to estimate the difference in mortality as it would have been had the trial included all screened patients with fulfilled inclusion criteria. Patients who were very likely to be included were weighted down and those who had a very low probability of being in the trial were weighted up.

Results:

The propensity score difference was 0.61. There were no significant differences in mortality between bivalirudin and heparin in the inverse-probability weighted analysis (hazard ratio 1.11, 95% confidence interval (0.73, 1.68)) at 30 days or 180 days (hazard ratio 0.98, 95% confidence interval (0.70, 1.36)).

Conclusion:

The propensity score difference demonstrated that the screened not-enrolled with fulfilled inclusion criteria and trial population were not similar. The inverse-probability weighted analysis showed no significant differences in mortality. From this, we conclude that the VALIDATE results may be generalized to the screened not-enrolled with fulfilled inclusion criteria.

Impact of bleeding complications after transcatheter mitral valve repair

BACKGROUND

Bleeding in the context of cardiac catheterization is frequent and negatively impacts on short- and long-term patient outcome. We evaluated the clinical impact of in-hospital bleeding events after transcatheter mitral valve repair (TMVr) in the long-term follow- up.

METHODS

586 consecutive patients treated with first-time TMVr were enrolled in this registry. In-hospital MVARC (Mitral Valve Academic Research Council) bleedings were assessed and patients were grouped according to the incidence of a bleeding event. Multivariate logistic regression was used to identify significant independent predictors of MVARC bleeding. This study received approval by local ethics committee.

RESULTS

78 patients (13.3%) suffered from an MVARC bleeding event (Access site-related bleedings: 46.2%; GI tract bleeding: 35.9%; Other bleedings: 17.9%). Among these bleeding subgroups, neither relevant differences in baseline characteristics nor in severity of bleeding events were observed. Despite not being an independent predictor for overall death in the multivariate Cox regression analysis, MVARC bleeding was associated with prolonged hospital stay. The ORBIT bleeding score was the best match to predictors of any MVARC bleeding found in our cohort (c-score overall cohort: 0.68; c-score GI bleeding cohort: 0.72).

CONCLUSION

MVARC bleedings after TMVr are frequent findings but were only in half of the cases related to the access site. The ORBIT score could be useful for identification of patients at high risk for non-access site bleeding and especially GI bleeding.

Dual inhibition of factor XIIa and factor XIa as a therapeutic approach for safe thromboprotection

Clinical practice shows that a critical unmet need in the field of medical device-associated thrombosis prevention is the availability of an anticoagulant therapy without hemorrhagic risk. In the quest for new drugs that are at least as effective as those currently available, while avoiding bleeding complications, molecules that target nearly every step of the coagulation pathway have been developed. Among these molecules, inhibitors of factor XII (FXII) or factor XI (FXI) are promising alternatives as deficiencies in these factors protect against thrombosis without causing spontaneous hemorrhage, as revealed by epidemiological and preclinical data. Ixodes ricinus-contact phase inhibitor (Ir-CPI), a new anticoagulant candidate with an innovative mechanism of action could be this ideal anticoagulant agent for safe prevention from clotting on medical devices. This protein, which selectively binds to FXIIa, FXIa, and plasma kallikrein and inhibits the reciprocal activation of FXII, prekallikrein, and FXI in human plasma, was shown to prevent thrombosis in an ovine cardiopulmonary bypass system associated with cardiac surgeries. Furthermore, as opposed to unfractionated heparin, Ir-CPI appears to be devoid of bleeding risk. This review outlines the rationale for targeting upstream coagulation factors in order to prevent medical device-associated thrombosis; examines the novel approaches under development; and focuses on Ir-CPI, which shows promising properties in the field of thrombosis prevention.

Large intracoronary thrombus and its management during primary PCI

Large intracoronary thrombus has been reported in significant number of patients with STEMI. Primary PCI is the current standard of care in patients of STEMI. Despite the availability of dual antiplatelets, GP IIb/IIIa inhibitor and effective anticoagulation regimens, large intracoronary thrombus remains one of the biggest challenge to interventional cardiologists during primary PCI. Large intracoronary thrombus may lead to distal embolization, no/slow reflow or embolization into a non-culprit vessel and is associated with adverse cardiovascular outcome. There is no ideal management strategy. We hereby discuss the current available methods/strategies to deal with large thrombus burden encountered during primary PCI, in the current manuscript.

2019 Canadian Cardiovascular Society/Canadian Association of Interventional Cardiology Guidelines on the Acute Management of ST-Elevation Myocardial Infarction: Focused Update on Regionalization and Reperfusion

Rapid reperfusion of the infarct-related artery is the cornerstone of therapy for the management of acute ST-elevation myocardial infarction (STEMI). Canada's geography presents unique challenges for timely delivery of reperfusion therapy for STEMI patients. The Canadian Cardiovascular Society/Canadian Association of Interventional Cardiology STEMI guideline was developed to provide advice regarding the optimal acute management of STEMI patients irrespective of where they are initially identified: in the field, at a non-percutaneous coronary intervention-capable centre or at a percutaneous coronary intervention-capable centre. We had also planned to evaluate and incorporate sex and gender considerations in the development of our recommendations. Unfortunately, inadequate enrollment of women in randomized trials, lack of publication of main outcomes stratified according to sex, and lack of inclusion of gender as a study variable in the available literature limited the feasibility of such an approach. The Grading Recommendations, Assessment, Development, and Evaluation system was used to develop specific evidence-based recommendations for the early identification of STEMI patients, practical aspects of patient transport, regional reperfusion decision-making, adjunctive prehospital interventions (oxygen, opioids, antiplatelet therapy), and procedural aspects of mechanical reperfusion (access site, thrombectomy, antithrombotic therapy, extent of revascularization). Emphasis is placed on integrating these recommendations as part of an organized regional network of STEMI care and the development of appropriate reperfusion and transportation pathways for any given region. It is anticipated that these guidelines will serve as a practical template to develop systems of care capable of providing optimal treatment for a wide range of STEMI patients.

Bivalirudin Versus Heparin During Intervention in Acute Coronary Syndrome: A Systematic Review of Randomized Trials

INTRODUCTION

Bivalirudin and heparin are the two most commonly used anticoagulants used during Percutaneous Coronary Intervention (PCI). The results of Randomized Controlled Trials (RCTs) comparing bivalirudin versus heparin monotherapy in the era of radial access are controversial, questioning the positive impact of bivalirudin on bleeding. The purpose of this systematic review is to summarize the results of RCTs comparing the efficacy and safety of bivalirudin versus heparin with or without Glycoprotein IIb/IIIa Inhibitors (GPI).

METHODS

This systematic review was performed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses PRISMA statements for reporting systematic reviews. We searched the National Library of Medicine PubMed, Clinicaltrial.gov and the Cochrane Central Register of Controlled Trials to include clinical studies comparing bivalirudin with heparin in patients undergoing PCI. Sixteen studies met inclusion criteria and were reviewed for the summary.

FINDINGS

Several RCTs and meta-analyses have demonstrated the superiority of bivalirudin over heparin plus routine GPI use in terms of preventing bleeding complications but at the expense of increased risk of ischemic complications such as stent thrombosis. The hypothesis of post- PCI bivalirudin infusion to mitigate the risk of acute stent thrombosis has been tested in various RCTs with conflicting results. In comparison, heparin offers the advantage of having a reversible agent, of lower cost and reduced incidence of ischemic complications.

CONCLUSION

Bivalirudin demonstrates its superiority over heparin plus GPI with better clinical outcomes in terms of less bleeding complications, thus making it as anticoagulation of choice particularly in patients at high risk of bleeding. Further studies are warranted for head to head comparison of bivalirudin to heparin monotherapy to establish an optimal heparin dosing regimen and post-PCI bivalirudin infusion to affirm its beneficial effect in reducing acute stent thrombosis.

Anticoagulant Effect of Standard Dose Heparin During Peripheral Endovascular Intervention

BACKGROUND

The objective of this clinical study was to investigate the anticoagulant effect of standard fixed dose of heparin during endovascular intervention in the lower extremity arteries.

METHODS

A prospective clinical pilot study was completed with retrospective quality review of patients between 2015 and 2017 (n = 61). Patients undergoing elective endovascular intervention for arterial insufficiency in the lower extremities were enrolled. A standard fixed intra-arterial dose of 5000 IU of unfractionated heparin (UFH) was administered during the procedure without adjustment for weight or monitoring. Activated clotting time (ACT) was measured before and ten minutes after heparin administration and at the end of the procedure. The primary study end point was the level of heparin anticoagulation after standard perioperative administration.

RESULTS

Mean age was 74 ± 9 years, 48% women. Mean weight was 74 ± 15 kg, and mean BMI, 25.6 ± 4.7 kg/m². The endovascular interventions were performed at the iliac arteries 19.7% (12/61), at the femoral popliteal segment 50.8 % (31/61), below the knee arteries 6.6% (4/61), and at multiple levels 13% (8/61). The perioperative mean ACT increased from baseline 155 ± 43 s (n = 31) to ten minutes after heparin administration 290 ± 70 s (n = 60) (P < 0.01) and was at the end of the procedure 276 ± 73 s (n = 59). Perioperative ACT ten minutes after heparin administration: 5.0% (3/60) of the patients had ACT <200 s, 25.0% (15/60) had ACT 200-250 s, 48.3% (29/60) ACT 251-349, and 21.7% (13/60) ACT ≥350 s. At the end of the procedure, 17.2 % (10/58) of the patients had ACT <200, 24.1 % (14/58) had ACT 200-250 s, 37.9% (22/58) ACT 251-349, and 20.7 % (12/58) ACT ≥350 s. The mean dose of heparin per kg body weight was 70 ± 15 IU/kg. There was a significant difference between the ACT groups when analyzing heparin dose per kg body weight: 54 ± 14 IU/kg for patients with ACT <200, 69 ± 13 IU/kg with ACT 200-250 s, 68 ± 13 IU/kg with ACT 251-349, and 81 ± 18 IU/kg with ACT >350 (P = 0.0095). The same pattern was seen for heparin dose per BMI and DuBois. In univariate logistic regression analysis, ACT ≥350 s was associated with lower body weight (OR 0.92; 95% CI 0.87-0.98; P = 0.008), lower BMI (OR 0.80; 95% CI 0.67-0.96; P = 0.014), and lower body surface area DuBois (OR 0.53; 95% 0.32-0.85; P = 0.009). In multivariable regression, the ACT association with body weight remained (OR 0.92; 95% 0.87-0.98; P = 0.008). There were no perioperative or immediate postoperative bleeding complications requiring blood transfusion or surgical intervention in this study cohort.

CONCLUSIONS

The standard heparin dosing of 5000 IU during endovascular intervention for arterial insufficiency in the lower extremities helps achieve ACT >200 s in almost all patients, but most patients were outside recommended target interval. To provide a more consistent and predictable heparinization, a weight-based bolus dose of 70 IU heparin/kg is recommended.

Periprocedural Myocardial Infarction in Contemporary Practice

"Periprocedural myocardial infarction (MI) occurs infrequently in the current era of percutaneous coronary interventions (PCI) and is associated with an increased risk of mortality and morbidity. Periprocedural MI can occur due to acute side branch occlusion, distal embolization, slow flow or no reflow phenomenon, abrupt vessel closure, and nonidentifiable mechanical processes. Therapeutic strategies to reduce the risk of periprocedural MI include dual antiplatelet therapy, intravenous cangrelor in the periprocedural setting, intravenous glycoprotein IIb/IIIa inhibitor in high-risk patients, anticoagulation with unfractionated heparin, low-molecular-weight heparin or bivalirudin, and embolic protection devices during saphenous vein graft interventions."

Relation of Bleeding Events to Mortality in Patients With ST-Segment Elevation Myocardial Infarction Treated by Percutaneous Coronary Intervention (a DANAMI-3 Substudy)

Bleeding events in relation to treatment of ST-segment elevation myocardial infarction (STEMI) have previously been associated with mortality. In this study, we investigated the incidence and prognosis of, and variables associated with serious bleedings within 30 days after primary percutaneous coronary intervention in patients from The Third Danish Study of Optimal Acute Treatment of Patients with ST-Segment Elevation Myocardial Infarction (DANAMI-3) (n = 2,217). Hospital charts were read within 30 days postadmission to assess bleeding events using thrombolysis in myocardial infarction (TIMI) and Bleeding Academic Research Consortium criteria. TIMI minor/major bleeding (TMMB) occurred in 59 patients (2.7%). Variables associated with TMMB were female gender (hazard ratio [HR] 3.9, 95% confidence interval [CI] 2.2 to 6.7, p <0.0001), symptom-to-catheterization time >3 hours (HR 1.9, 95% CI 1.1 to 3.3, p = 0.02), use of glycoprotein IIb/IIIa inhibitor (HR 2.1, 95% CI 1.2 to 3.7, p = 0.01), and increasing S-creatinine (HR 1.1, 95% CI 1.0 to 1.2, p = 0.001). Undergoing 2 in-hospital procedures were not associated with increased risk of TMMB. TMMB was strongly associated with 30-day mortality in multivariable analysis (HR 4.8, 95% CI 2.2 to 10.4, p <0.0001) but not with mortality days 31 to 365. When excluding fatal bleedings from the analysis, a TMMB was no longer associated with 30-day mortality. In conclusion, we found that in a contemporary STEMI-population, the incidence of 30-day TMMB was low. A TMMB was strongly associated with 30-day mortality but not with mortality days 31 to 365. If patients survived a serious bleeding, their short- and long-term prognoses were not affected.

Antithrombotic treatment in peripheral artery disease

Abstract. This review treats antithrombotic use for peripheral arterial disease (PAD). In asymptomatic patients, there are no scientific data to support single antiplatelet therapy (SAPT) for primary prophylaxis. In symptomatic PAD, SAPT with aspirin or clopidogrel is indicated. The efficacy of aspirin is controversial. Clopidogrel may be preferred over aspirin. Ticagrelor is not superior to clopidogrel in reducing major adverse cardiovascular events and major adverse limb events, but lowers the risk of ischaemic stroke. In symptomatic PAD, dual antiplatelet therapy (DAPT) with clopidogrel and aspirin does not provide benefit over SAPT with aspirin alone and is associated with increased risk of major bleeding. DAPT with ticagrelor 60 mg b. i. d. and aspirin provides a significant major adverse cardiovascular events reduction in symptomatic PAD patients and may be considered in PAD patients with prior myocardial infarction. The use of a new thrombin receptor antagonist, vorapaxar, on top of SAPT or DAPT with aspirin and/or clopidogrel, reduces the risk of acute limb ischaemia and peripheral artery revascularization in patients with symptomatic PAD, at the cost of an increased risk for bleeding. Rivaroxaban (2.5 mg b. i. d.) plus aspirin (100 mg daily) is the first antithrombotic association that proved significant benefit for PAD patients, in terms of strong endpoints – total mortality and cardiovascular mortality. Therefore, this association shows the strongest evidence for secondary prevention of symptomatic PAD patients. In PAD patients undergoing percutaneous peripheral interventions, at least four weeks of DAPT with aspirin and clopidogrel is recommended after infrainguinal stent implantation. Stenting below-the-knee arteries is often followed by a longer period of DAPT, but no specific evidence is available. Anticoagulation is mandatory to prevent arterial occlusion during radial or brachial invasive procedures. The strategy includes use of unfractioned heparin, bivalirudin or enoxaparin. Vitamin K antagonists may be considered after autologous vein infrainguinal bypass.