Heparin or enoxaparin anticoagulation for primary percutaneous coronary intervention

Safety and Efficacy of Enoxaparin During Low-Risk Elective Percutaneous Coronary Intervention

Intravenous unfractionated heparin (UFH) is the most frequently used anticoagulant for percutaneous coronary intervention (PCI). Intravenous enoxaparin, a low-molecular-weight heparin, has superior pharmacokinetic and pharmacodynamic properties compared with UFH. Multiple trials have shown enoxaparin to be safe and effective in PCI. However, there has not been a contemporary study evaluating its safety and efficacy. To assess its efficacy and safety, intravenous enoxaparin during PCI through radial artery access was evaluated in PCI patients from January 2015 to December 2019. Outcomes included procedural success, all-cause mortality, ischemic complications, and bleeding complications from the time of the procedure until hospital discharge. A total of 1019 consecutive eligible patients were identified. Median age was 63 years, and 70% were men. The indication for PCI was stable and unstable angina in two-thirds of cases (77%). Few patients had myocardial infarction (MI) (2.2%) as the indication for intervention. The procedure was successful in 98.2% of cases. There were no deaths. Procedural MI occurred in 0.3% of patients. Acute stent thrombosis occurred in 0.4%. Urgent revascularization and stroke occurred in 0.1% each. Small wrist hematomas occurred in 0.3% and all were managed conservatively. There was one radial artery pseudoaneurysm. There were no cases of major bleeding. In conclusion, this single-center study showed that intravenous enoxaparin is a reasonable alternative anticoagulant for use in low-risk and elective non-MI PCI through radial artery access.

Pharmacological Modulation by Low Molecular Weight Heparin of Purinergic Signaling in Cardiac Cells Prevents Arrhythmia and Lethality Induced by Myocardial Infarction

Background: Although several studies suggest that heparins prevent arrhythmias caused by acute myocardial infarction (AMI), the molecular mechanisms involved remain unclear. To investigate the involvement of pharmacological modulation of adenosine (ADO) signaling in cardiac cells by a low-molecular weight heparin (enoxaparin; ENOX) used in AMI therapy, the effects of ENOX on the incidences of ventricular arrhythmias (VA), atrioventricular block (AVB), and lethality (LET) induced by cardiac ischemia and reperfusion (CIR) were evaluated, with or without ADO signaling blockers. Methods: To induce CIR, adult male Wistar rats were anesthetized and subjected to CIR. Electrocardiogram (ECG) analysis was used to evaluate CIR-induced VA, AVB, and LET incidence, after treatment with ENOX. ENOX effects were evaluated in the absence or presence of an ADO A1-receptor antagonist (DPCPX) and/or an inhibitor of ABC transporter-mediated cAMP efflux (probenecid, PROB). Results: VA incidence was similar between ENOX-treated (66%) and control rats (83%), but AVB (from 83% to 33%) and LET (from 75% to 25%) incidences were significantly lower in rats treated with ENOX. These cardioprotective effects were blocked by either PROB or DPCPX. Conclusion: These results indicate that ENOX was effective in preventing severe and lethal arrhythmias induced by CIR due to pharmacological modulation of ADO signaling in cardiac cells, suggesting that this cardioprotective strategy could be promising in AMI therapy.

Periprocedural Antithrombotic Treatment in Complex Percutaneous Coronary Intervention

ABSTRACT

In recent years, the management of complex lesions in patients undergoing percutaneous coronary intervention (PCI) constitutes a field of high interest and concern for the interventional cardiology. As more and more studies demonstrate the increased hazard of ischemic events in this group of patients, it is of paramount importance for the physicians to choose the optimal periprocedural (pre-PCI, during-PCI and post-PCI) antithrombotic treatment strategies wisely. Evidence regarding the safety and efficacy of current anticoagulation recommendation, the possible beneficial role of the pretreatment with a potent P2Y12 inhibitor in the subgroup of patients with non-ST segment elevation myocardial infarction with complex lesions, and the impact of a more potent P2Y12 inhibitor in individuals with stable coronary artery disease undergoing complex PCI are needed. This will provide and serve as a guide to clinicians to deploy the maximum efficacy of the current choices of antithrombotic therapy, which will lead to an optimal balance between safety and efficacy in this demanding clinical scenario.

Low-Dose Unfractionated Heparin with Sequential Enoxaparin in Patients with Diabetes Mellitus and Complex Coronary Artery Disease during Elective Percutaneous Coronary Intervention

Background:

Despite its limitations, unfractionated heparin (UFH) has been the standard anticoagulant used during percutaneous coronary intervention (PCI). This study compared the safety of low-dose UFH with sequential enoxaparin with that of UFH in patients with diabetes mellitus (DM) and complex coronary artery disease receiving elective PCI.

Methods:

In this retrospective study, 514 consecutive patients with atherosclerotic cardiovascular diseases and type 2 DM were admitted to the hospital and received selective PCI, from January 2013 to December 2015. All patients with PCI received low-dose UFH with enoxaparin (intraductal 50 U/kg UFH and 0.75 mg/kg enoxaparin, n = 254; UFH-Enox group) or UFH only (intraductal 100 U/kg UFH, n = 260; UFH group). The study endpoints were major adverse cardiac events (MACEs), namely death, myocardial infarction (MI), stroke, target-vessel immediate revascularization (TVR), and thrombolysis in MI (TIMI) major bleeding, within 30 days and 1 year after PCI. Any catheter thrombosis during the procedure was recorded.

Results:

Only one patient had an intraductal thrombus in the UFH group. At the 30-day follow-up, no MACE occurred in any group; seven and five cases of recurrent angina and/or rehospitalization were reported in the UFH-Enox and UFH groups, respectively; there was no significant difference between the two groups (χ² = 0.11, P = 0.77). There was no TIMI major bleeding in the groups. With respect to the 1-year endpoint, two cases of recurrent MI and two of TVRs were reported in the UFH-Enox group, whereas in the UFH group, one case of recurrent MI and three of TVRs were reported; no significant difference existed between the two groups (χ² = 0, P = 0.99). There were 30 and 25 recurrent angina and/or rehospitalizations in the UFH-Enox and UFH groups, respectively; there was no significant difference between the two groups (χ² = 0.37, P = 0.57).

Conclusion:

In elective PCI, low-dose UFH with sequential enoxaparin has similar effects and safety to the UFH-only method.

Suboptimal anticoagulation with pre-hospital heparin in ST-elevation myocardial infarction

This is a prospective, observational study performed in all consecutive ST-elevation myocardial infarction (STEMI) patients who had activated clotting time (ACT) measurement on arrival in the cathlab before coronary angiography. We studied the therapeutic effects of a pre-hospital fixed heparin bolus dose in consecutive patients with STEMI. A total of 1,533 patients received pre-hospital administration of aspirin, high dose clopidogrel (600 mg) and a fixed bolus dose of 5,000 IU unfractionated heparin (UFH), according to the national ambulance protocols. Some patients were also treated with glycoprotein IIb/IIIa inhibitors (GPI) in the ambulance. A therapeutic ACT range was defined according to the ESC guidelines as 200–250 seconds when patients had GPI pretreatment and 250–350 seconds when no GPI pretreatment. Of the 1,533 patients, 216 patients (14.1%) had an ACT within the therapeutic range, 82.3% of the patients had a too low ACT, whereas 3.5% of the patients had a too high ACT. After multivariable analysis, the only independent predictor of a too low ACT was increasing weight (odds ratio 1.02/kg, 95% confidence interval 1.01–1.03, p=0.001). Patients with a too low ACT had less often an open infarct related vessel (initial TIMI flow 2,3) as compared to patients with an ACT in range (36.5% vs. 45.9%, p=0.013). In only a minority of patients with STEMI, pre-hospital treatment with a fixed bolus dose UFH is within the therapeutic ACT range. Increased weight is an independent determinant of a too low ACT. We strongly recommend weight adjusted administration of UFH in the ambulance.

Relation Between TRCA Complication Rates and Peak ACT Levels Stratified According to the BMI Tertiles

We evaluated the efficacy and safety of the fixed dose of 5000 IU unfractionated heparin (UFH) represented as peak activated clotting time (ACT) according to the body mass index (BMI) tertiles in patients undergoing diagnostic transradial coronary angiography (TRCA). A total of 422 patients were included in the present study, 84 in the normal weight group, 218 in the overweight group, and the 120 in the grades 1 and 2 obesity groups. Radial artery occlusion (RAO) was observed in 29 (6.8%) patients and the hematoma was observed in 43 (10.1%) patients. The rate of RAO and hematoma did not differ across the BMI tertiles ( P = .749 and P = .066). Also, peak ACT and procedure duration did not differ between the study groups ( P = .703 and P = .999). The only independent predictor of hematoma was sheath/radial artery diameter ( P = .011) and the independent predictors for RAO were peak ACT, sheath/radial artery diameter, and procedure duration ( P = .001, P = .028, and P < .001, respectively). In conclusion, a fixed dose of 5000 IU UFH is safe and effective regardless of the BMI in diagnostic TRCA procedure.

Administration of low molecular weight and unfractionated heparin during percutaneous coronary intervention

This systematic review with meta-analysis sought to determine the efficacy and safety of unfractionated heparin (UFH) and low molecular weight heparin (LMWH) on clinical outcomes following percutaneous coronary intervention. Medline, Embase, Elsevier, and web of knowledge as well as Google scholar literature were used for selecting appropriate studies with randomized controlled design. After screening 445 studies, a total of 23 trials (including a total of 43,912 patients) were identified that reported outcomes. Pooled analysis revealed that LMWH compared to UFH could significantly increase thrombolysis in myocardial infarction grade 3 flow (p<0.001), which was associated with similar target vessel revascularization (p=0.6), similar incidence of stroke (p=0.7), and significantly lower incidence of re-myocardial infarction (p<0.001), major bleeding (p=0.02) and mortality (p<0.001). Overall, LMWH was shown to be a useful type of heparin for patients with MI undergoing PCI, due to its higher efficacy and lower rate of complication compared to UFH. It is also associated with increased myocardial perfusion, decreased major hemorrhage, and mortality.

Influence of Body Mass Index on the Activated Clotting Time Under Weight-Based Heparin Dose

BACKGROUND

Activated clotting time (ACT) has been successfully applied during percutaneous coronary intervention (PCI) to monitor the extent of thrombin inhibition and anti-coagulation from unfractionated heparin (UFH) aiming to reduce the incidence of thrombotic adverse events and hemorrhagic complications. And this investigation was to explore the influence of body mass index (BMI) on ACT in patients received weight-based dose of UFH during PCI treatment.

METHODS

78 male patients undergoing coronary angiography or PCI treatment with a mean age of 63.86 ± 6.89 years were enrolled in this study. The patients were statistically divided into four quartiles according to their BMI. The ACT values were recorded as ACT0 , ACT5 , ACT10 , ACT30 and ACT60 , respectively. Taking the preoperative ACT0 as reference, and the differences of the other ACT values with ACT0 was indicated as ΔACTs. ACT values peaked at 5 min in 33.33% of the patients, 10 min in 51.33% of the patients and 30 min in 15.34% of the patients, respectively.

RESULTS

In addition, significant differences were found in overall maximum post-UFH ACT values among all BMI quartiles. UFH doses per blood volume were significantly different among the BMI quartiles, showing a positive association with BMI quartiles; further evidence revealed that the areas under the ΔACT-time curves increased gradually from quartile I to quartile IV. The proportions of ACT60 > 250 s and ACT60 > 300 s were found to be positively correlated with the increased BMI at 60 min after heparin loading.

CONCLUSIONS

The results of our study have shown that a standardized dosing nomogram that uses the actual body weight to calculate the heparin doses may result in UFH overdose for patients with higher BMI compared to patients with lower BMI.

A direct comparison of intravenous enoxaparin with unfractionated heparin in primary percutaneous coronary intervention (from the ATOLL trial)

Intravenous enoxaparin did not reduce significantly the primary end point (p = 0.06) compared with unfractionated heparin (UFH) in the randomized Acute Myocardial Infarction Treated with primary angioplasty and intravenous enoxaparin Or unfractionated heparin to Lower ischemic and bleeding events at short- and Long-term follow-up (ATOLL) trial. We present the results of the prespecified per-protocol analysis excluding patients who did not receive the treatment allocated by randomization or received both enoxaparin and UFH. We evaluated all-cause mortality, complication of myocardial infarction, procedural failure, or major bleeding (primary end point) and all-cause mortality, recurrent acute coronary syndrome, or urgent revascularization (main secondary end point). Baseline and procedural characteristics were well balanced between the 2 treatment groups. Of 910 randomized patients, 795 patients (87.4%) were treated according to the protocol with consistent anticoagulation using intravenous enoxaparin (n = 400) or UFH (n = 395). Enoxaparin reduced significantly the rates of the primary end point (relative risk [RR] 0.76, 95% confidence interval [CI] 0.62 to 0.94, p = 0.012) and the main secondary end point (RR 0.37, 95% CI 0.22 to 0.63, p <0.0001). There was less major bleeding with enoxaparin (RR 0.46, 95% CI 0.21 to 1.01, p = 0.050) contributing to the significant improvement of the net clinical benefit (RR 0.46, 95% CI 0.3 to 0.74, p = 0.0002). All-cause mortality was also reduced with enoxaparin (RR 0.36, 95% CI 0.18 to 0.74, p = 0.003). In conclusion, in the per-protocol analysis of the ATOLL trial, pertinent to >87% of the study population, enoxaparin was superior to UFH in reducing ischemic end points and mortality.

Adjunctive Pharmacotherapy for Thrombotic Coronary Lesions

Patients with unstable coronary syndromes are often found to have intracoronary thrombus on angiography. Despite advancements in catheter-based treatments for coronary disease, these lesions remain challenging, as percutaneous coronary intervention of thrombus-containing lesions may be associated with worse outcomes. This article reviews the literature on adjunctive pharmacotherapy in the treatment of thrombotic coronary lesions with special focus on ST-segment elevation myocardial infarction, lesions with high thrombus burden, and saphenous vein graft intervention.

Impact of transfer time on mortality in acute coronary syndrome with ST-segment elevation treated by angioplasty

BACKGROUND

In primary percutaneous coronary intervention (pPCI), conflicting data exist on the relative importance of patient presentation time (time from symptom onset (SO) to first medical contact [FMC]) and transfer time (time from FMC to sheath insertion).

OBJECTIVES

To evaluate the impact of transfer time on mortality in an unselected ST-elevation myocardial infarction (STEMI) population treated with pPCI.

METHODS

In a well-organized urban network, using mobile intensive care units (MICU) whenever possible, the impact of transfer time on inhospital mortality was evaluated in 703 unselected consecutive STEMI patients transferred for pPCI.

RESULTS

Our STEMI population included patients with cardiogenic shock (5.3%) and out-of-hospital cardiac arrest (3.7%). Longer transfer times were found to be associated with a stepwise increase in mortality ranging from 2.99% in the first quartile (Q1) up to 8.65% in the fourth quartile (Q4) (P=0.005). This result was noted in patients presenting early (≤2h of SO, 0.96% for Q1 vs. 9.8% for Q4, P=0.006) but not in late presenters (>2h of SO, 7.00% for Q1 vs. 7.8% for Q4, P=0.85). After adjustment for confounding variables such as the severity of patients, the relationship between mortality and transfer time was no longer apparent.

CONCLUSIONS

In a well-organized urban network dedicated to pPCI, including unselected STEMI patients, transfer time does not appear to be a major contributor to mortality. The relationship of transfer time to mortality seems to be dependent on presentation time and patients' clinical severity.

Efficacy and safety of enoxaparin versus unfractionated heparin during percutaneous coronary intervention: systematic review and meta-analysis

OBJECTIVE

To determine the efficacy and safety of enoxaparin compared with unfractionated heparin during percutaneous coronary intervention.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Medline and Cochrane database of systematic reviews, January 1996 to May 2011.

STUDY SELECTION

Randomised and non-randomised studies comparing enoxaparin with unfractionated heparin during percutaneous coronary intervention and reporting on both mortality (efficacy end point) and major bleeding (safety end point) outcomes.

DATA EXTRACTION

Sample size, characteristics, and outcomes, extracted independently and analysed.

DATA SYNTHESIS

23 trials representing 30,966 patients were identified, including 10,243 patients (33.1%) undergoing primary percutaneous coronary intervention for ST elevation myocardial infarction, 8750 (28.2%) undergoing secondary percutaneous coronary intervention after fibrinolysis, and 11,973 (38.7%) with non-ST elevation acute coronary syndrome or stable patients scheduled for percutaneous coronary intervention. A total of 13,943 patients (45.0%) received enoxaparin and 17,023 (55.0%) unfractionated heparin. Enoxaparin was associated with significant reductions in death (relative risk 0.66, 95% confidence interval 0.57 to 0.76; P<0.001), the composite of death or myocardial infarction (0.68, 0.57 to 0.81; P<0.001), and complications of myocardial infarction (0.75, 0.6 to 0.85; P<0.001), and a reduction in incidence of major bleeding (0.80, 0.68 to 0.95; P=0.009). In patients who underwent primary percutaneous coronary intervention, the reduction in death (0.52, 0.42 to 0.64; P<0.001) was particularly significant and associated with a reduction in major bleeding (0.72, 0.56 to 0.93; P=0.01).

CONCLUSION

Enoxaparin seems to be superior to unfractionated heparin in reducing mortality and bleeding outcomes during percutaneous coronary intervention and particularly in patients undergoing primary percutaneous coronary intervention for ST elevation myocardial infarction.

Low-molecular-weight heparins vs. unfractionated heparin in the setting of percutaneous coronary intervention for ST-elevation myocardial infarction: a meta-analysis

BACKGROUND

The aim of the current study was to perform two separate meta-analyses of available studies comparing low-molecular-weight heparins (LMWHs) vs. unfractionated heparin (UFH) in ST-elevation myocardial infarction (STEMI) patients treated (i) with primary percutaneous coronary intervention (pPCI) or (ii) with PCI after thrombolysis.

METHODS

All-cause mortality was the pre-specified primary endpoint and major bleeding complications were recorded as the secondary endpoints. Relative risk (RR) with a 95% confidence interval (CI) and absolute risk reduction (ARR) were chosen as the effect measure.

RESULTS

Ten studies comprising 16,286 patients were included. The median follow-up was 2 months for the primary endpoint. Among LMWHs, enoxaparin was the compound most frequently used. In the pPCI group, LMWHs were associated with a reduction in mortality [RR (95% CI) = 0.51 (0.41-0.64), P < 0.001, ARR = 3%] and major bleeding [RR (95% CI) = 0.68 (0.49-0.94), P = 0.02, ARR = 2.0%] as compared with UFH. Conversely, no clear evidence of benefits with LWMHs was observed in the PCI group after thrombolysis. Meta-regression showed that patients with a higher baseline risk had greater benefits from LMWHs (r = 0.72, P = 0.02).

CONCLUSIONS

LMWHs were associated with greater efficacy and safety than UFH in STEMI patients treated with pPCI, with a significant relationship between risk profile and clinical benefits. Based on this meta-analysis, LMWHs may be considered as a preferred anticoagulant among STEMI patients undergoing pPCI.

Intravenous enoxaparin or unfractionated heparin in primary percutaneous coronary intervention for ST-elevation myocardial infarction: the international randomised open-label ATOLL trial

BACKGROUND

Primary percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction has traditionally been supported by unfractionated heparin, which has never been directly compared with a new anticoagulant using consistent anticoagulation and similar antiplatelet strategies in both groups. We compared traditional heparin treatment with intravenous enoxaparin in primary PCI.

METHODS

In a randomised open-label trial, patients presenting with ST-elevation myocardial infarction were randomly assigned (1:1) to receive an intravenous bolus of 0·5 mg/kg of enoxaparin or unfractionated heparin before primary PCI. Wherever possible, medical teams travelling in mobile intensive care units (ambulances) selected, randomly assigned (using an interactive voice response system at the central randomisation centre), and treated patients. Patients who had received any anticoagulant before randomisation were excluded. Patients and caregivers were not masked to treatment allocation. The primary endpoint was 30-day incidence of death, complication of myocardial infarction, procedure failure, or major bleeding. The main secondary endpoint was the composite of death, recurrent acute coronary syndrome, or urgent revascularisation. Analysis was by intention to treat. This trial is registered at ClinicalTrials.gov, number NCT00718471.

FINDINGS

910 patients were assigned to treatment with enoxaparin (n=450) or unfractionated heparin (n=460). The primary endpoint occurred in 126 (28%) patients after anticoagulation with enoxaparin versus 155 (34%) patients on unfractionated heparin (relative risk [RR] 0·83, 95% CI 0·68-1·01, p=0·06). The incidence of death (enoxaparin, 17 [4%] vs heparin, 29 [6%] patients; p=0·08), complication of myocardial infarction (20 [4%] vs 29 [6%]; p=0·21), procedure failure (100 [26%] vs 109 [28%]; p=0·61), and major bleeding (20 [5%] vs 22 [5%]; p=0·79) did not differ between groups. Enoxaparin resulted in a significantly reduced rate of the main secondary endpoint (30 [7%] vs 52 [11%] patients; RR 0·59, 95% CI 0·38-0·91, p=0·015). Death, complication of myocardial infarction, or major bleeding (46 [10%] vs 69 [15%] patients; p=0·03), death or complication of myocardial infarction (35 [8%] vs 57 [12%]; p=0·02), and death, recurrent myocardial infarction, or urgent revascularisation (23 [5%] vs 39 [8%]; p=0·04) were all reduced with enoxaparin.

INTERPRETATION

Intravenous enoxaparin compared with unfractionated heparin significantly reduced clinical ischaemic outcomes without differences in bleeding and procedural success. Therefore, enoxaparin provided an improvement in net clinical benefit in patients undergoing primary PCI.

FUNDING

Direction de la Recherche Clinique, Assistance Publique-Hôpitaux de Paris; Sanofi-Aventis.