Acute Stent Thrombosis After Primary Percutaneous Coronary Intervention

Differential Use of Glycoprotein IIb/IIIa Inhibitors with Bivalirudin in Patients with STEMI Undergoing PCI: A Systematic Review and Meta-Analysis

AIM

The efficacy and safety of bivalirudin when used concurrently with glycoprotein IIb/IIIa inhibitors (GPI) is uncertain. In this systematic review and meta-analysis, we aimed to evaluate the efficacy and safety of bivalirudin versus heparin in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI) and to explore the impact of differential use (greater and balanced) of GPI.

METHODS

Online databases were queried from inception to March 2023 to identify eight randomized controlled trials (n = 22,483) for inclusion. The primary outcomes included all-cause mortality, major bleeding, major adverse cardiovascular events (MACE), and net adverse clinical events (NACE). Secondary efficacy endpoints included cardiac death, reinfarction, stent thrombosis (ST), and stroke. Data were pooled using a random-effects model to derive risk ratios (RRs) and 95% confidence intervals (CIs).

RESULTS

When compared to heparin, bivalirudin was associated with a significant reduction in all-cause mortality (RR 0.83; 95% CI 0.72-0.97; P = 0.02), major bleeding (RR 0.73; 95% CI 0.57-0.93; P = 0.01), cardiac death (RR 0.79; 95% CI 0.66-0.94; P = 0.01), and NACE (RR 0.80; 95% CI 0.72-0.89; P < 0.0001). However, while the bivalirudin arm showed an increased likelihood of ST in the greater GPI subgroup (RR 1.70; 95% CI 1.13-2.56; P = 0.01), it was associated with a decreased likelihood of ST in the balanced GPI subgroup (RR 0.40; 95% CI 0.24-0.65; P = 0.0003).

CONCLUSION

Overall, our findings suggest that bivalirudin may be a more efficacious intervention than heparin for reducing certain adverse events in patients with STEMI undergoing primary PCI.

Bivalirudin in acute coronary syndromes

INTRODUCTION

Bivalirudin, a bivalent direct thrombin inhibitor, has been developed to reduce bleeding without any trade-off in thrombotic events in acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI).

AREAS COVERED

Despite showing a superior safety profile compared with unfractionated heparin (UFH), bivalirudin is not considered the anticoagulant of choice in ACS patients undergoing PCI, mainly because of an increased rate of acute stent thrombosis (ST) shown by several randomized controlled trials (RCTs), in addition to limited availability in certain countries and increased costs. However, RCTs on bivalirudin have been characterized by several confounding factors hindering the interpretation of its safety and efficacy compared with UFH among the spectrum of ACS patients. Furthermore, a significant body of evidence has demonstrated that the risk of acute ST can be mitigated by a full-dose infusion regimen following PCI, without compromising the favorable safety profile compared to UFH.

EXPERT OPINION

In light of the increased understanding of the prognostic relevance of bleeding events and the excellent safety profile of bivalirudin, recent trial evidence may allow for this anticoagulant agent to reemerge and have a more prominent role in the management of ACS patients undergoing PCI.

Bivalirudin plus a high-dose infusion versus heparin monotherapy in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention: a randomised trial

BACKGROUND

Previous randomised trials of bivalirudin versus heparin in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI) have reported conflicting results, in part because of treatment with different pharmacological regimens. We designed a large-scale trial examining bivalirudin with a post-PCI high-dose infusion compared with heparin alone, the regimens that previous studies have shown to have the best balance of safety and efficacy.

METHODS

BRIGHT-4 was an investigator-initiated, open-label, randomised controlled trial conducted at 87 clinical centres in 63 cities in China. Patients with STEMI undergoing primary PCI with radial artery access within 48 h of symptom onset who had not received previous fibrinolytic therapy, anticoagulants, or glycoprotein IIb/IIIa inhibitors were randomly assigned (1:1) to receive bivalirudin with a post-PCI high-dose infusion for 2-4 h or unfractionated heparin monotherapy. There was no masking. Glycoprotein IIb/IIIa inhibitor use was reserved for procedural thrombotic complications in both groups. The primary endpoint was a composite of all-cause mortality or Bleeding Academic Research Consortium (BARC) types 3-5 bleeding at 30 days. This trial is registered with ClinicalTrials.gov (NCT03822975), and is ongoing.

FINDINGS

Between Feb 14, 2019, and April 7, 2022, a total of 6016 patients with STEMI undergoing primary PCI were randomly assigned to receive either bivalirudin plus a high-dose infusion after PCI (n=3009) or unfractionated heparin monotherapy (n=3007). Radial artery access was used in 5593 (93·1%) of 6008 patients. Compared with heparin monotherapy, bivalirudin reduced the 30-day rate of the primary endpoint (132 events [4·39%] in the heparin group vs 92 events [3·06%] in the bivalirudin group; difference, 1·33%, 95% CI 0·38-2·29%; hazard ratio [HR] 0·69, 95% CI 0·53-0·91; p=0·0070). All-cause mortality within 30 days occurred in 118 (3·92%) heparin-assigned patients and in 89 (2·96%) bivalirudin-assigned patients (HR 0·75; 95% CI 0·57-0·99; p=0·0420), and BARC types 3-5 bleeding occurred in 24 (0·80%) heparin-assigned patients and five (0·17%) bivalirudin-assigned patients (HR 0·21; 95% CI 0·08-0·54; p=0·0014). There were no significant differences in the 30-day rates of reinfarction, stroke, or ischaemia-driven target vessel revascularisation between the groups. Within 30 days, stent thrombosis occurred in 11 (0·37%) of bivalirudin-assigned patients and 33 (1·10%) of heparin-assigned patients (p=0·0015).

INTERPRETATION

In patients with STEMI undergoing primary PCI predominantly with radial artery access, anticoagulation with bivalirudin plus a post-PCI high-dose infusion for 2-4 h significantly reduced the 30-day composite rate of all-cause mortality or BARC types 3-5 major bleeding compared with heparin monotherapy.

FUNDING

Chinese Society of Cardiology Foundation (CSCF2019A01), and a research grant from Jiangsu Hengrui Pharmaceuticals.

Factors Impacting Stent Thrombosis in Patients With Percutaneous Coronary Intervention and Coronary Stenting: A Systematic Review and Meta-Analysis

Stent thrombosis (ST) is a frequently reported complication in cardiac patients with percutaneous coronary intervention (PCI) that adversely impacts their prognostic outcomes. Medical literature reveals several baseline characteristics of PCI patients that may predict their predisposition to ST and its potential complications. Our systematic review and meta-analysis aimed to determine the diagnostic significance of these baseline parameters in terms of determining the risk of ST among adult patients with PCI. 

We statistically evaluated 18 baseline characteristics of more than 15,500 PCI patients to delineate their stent thrombosis attribution. We included a number of articles focusing on baseline parameters in-stent thrombosis-related PCI scenarios. We explored the articles of interest based on inclusion/exclusion parameters across PubMed, JSTOR, Cochrane library, Google Scholar, and Embase. Medical subject headings (MeSH) words included “stent thrombosis,” “percutaneous coronary intervention,” and “coronary stenting.” We extracted the research articles published between 2005 and 2021 on April 20, 2021. The included studies also focused on procedures and clinical factors concerning their association with PCI-related ST.

Our findings ruled out the progression of abnormal left ventricular ejection fraction (LVEF)-related stent thrombosis in PCI patients (odds ratio {OR}: 9.68, 95% CI: 1.88-49.90, p=0.007). We found an insignificant clinical correlation between stent thrombosis and PCI in the setting of acute coronary syndrome (ACS). Our study outcomes further revealed the absence of stent thrombosis in PCI patients with antiplatelet prescription (OR: 32.42, 95% CI: 21.28-49.39). The findings affirmed the absence of ST in PCI patients receiving aspirin therapy (OR: 32.77, 95% CI: 18.73-57.34; OR: 4.59, 95% CI: 1.97-10.73). The majority of the included studies negated the clinical correlation of stent thrombosis with diabetes mellitus in the setting of PCI (OR: 0.49, 95% CI: 0.06-3.78). Our study did not reveal statistically significant results based on stent thrombosis in PCI patients with drug-eluting stents (OR: 2.91, 95% CI: 0.35-24.49). The findings also did not reveal the impact of cardiac biomarker elevation on stent thrombosis in PCI patients (OR: 8.42, 95% CI: 2.54-27.98, p=0.0005). Eight studies revealed a statistically insignificant correlation between myocardial infarction and stent thrombosis in PCI scenarios (OR: 2.69, 95% CI: 0.89-8.11, p=0.08). The clinical correlation between PCI and stent thrombosis/major bleeding in the setting of hypertension also proved statistically insignificant at 0.67 (OR: 1.31, 95% CI: 0.38-4.51, p=0.97). The study findings did not correlate mean body mass index and multivessel coronary artery disease with ST in PCI scenarios (OR: 1.98, 95% CI: 0.02-239.58, p=0.78; OR: 1.09, 95% CI: 0.58-2.04, p=0.80). Only two studies revealed statistically significant results confirming stent thrombosis in PCI patients with a prior history of PCI (OR: 0.49, 95% CI: 0.23-1.06; OR: 0.33, 95% CI: 0.02-5.59; p=0.03).

Our findings question the clinical significance of baseline characteristics in terms of predicting stent thrombosis in PCI patients. The results support the requirement of future studies to investigate complex interactions between procedural, medicinal, genetic, and patient-related factors contributing to the development of stent thrombosis in PCI patients. 

Bivalirudin Versus Heparin Monotherapy in ST-Segment-Elevation Myocardial Infarction

BACKGROUND

Bivalirudin was not superior to unfractionated heparin in patients with myocardial infarction (MI) treated with percutaneous coronary intervention and no planned use of GPI (glycoprotein IIb/IIIa inhibitors) in contemporary clinical practice of radial access and potent P2Y₁₂-inhibitors in the VALIDATE-SWEDEHEART randomized clinical trial (Bivalirudin Versus Heparin in STEMI and NSTEMI Patients on Modern Antiplatelet Therapy-Swedish Web-System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies Registry).

METHODS

In this prespecified separately powered subgroup analysis, we included patients with ST-segment-elevation MI undergoing primary percutaneous coronary intervention with the primary composite end point of all-cause death, MI, or major bleeding event within 180 days.

RESULTS

Among the 6006 patients enrolled in the trial, 3005 patients with ST-segment-elevation MI were randomized to receive bivalirudin or heparin. The mean age was 66.8 years. According to protocol recommendations, 87% were treated with potent oral P2Y₁₂-inhibitors before start of angiography and radial access was used in 90%. GPI was used in 51 (3.4%) and 74 (4.9%) of patients randomized to receive bivalirudin and heparin, respectively. The primary end point occurred in 12.5% (187 of 1501) and 13.0% (196 of 1504; hazard ratio [HR], 0.95 [95% CI, 0.78-1.17], P=0.64) with consistent results in all major subgroups. All-cause death occurred in 3.9% versus 3.9% (HR, 1.00 [0.70-1.45], P=0.98), MI in 1.7% versus 2.2% (HR, 0.76 [0.45-1.28], P=0.30), major bleeding in 8.3% versus 8.0% (HR, 1.04 [0.81-1.33], P=0.78), and definite stent thrombosis in 0.5% versus 1.3% (HR, 0.42 [0.18-0.96], P=0.04).

CONCLUSIONS

In patients with ST-segment-elevation MI undergoing primary percutaneous coronary intervention with radial access and receiving current recommended treatments with potent P2Y₁₂-inhibitors rate of the composite of all-cause death, MI, or major bleeding was not lower in those randomized to receive bivalirudin as compared with heparin. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02311231.

Efficacy and safety of next-generation tick transcriptome-derived direct thrombin inhibitors

Despite their limitations, unfractionated heparin (UFH) and bivalirudin remain standard-of-care parenteral anticoagulants for percutaneous coronary intervention (PCI). We discovered novel direct thrombin inhibitors (DTIs) from tick salivary transcriptomes and optimised their pharmacologic activity. The most potent, ultravariegin, inhibits thrombin with a K_i of 4.0 pM, 445-fold better than bivalirudin. Unexpectedly, despite their greater antithrombotic effect, variegin/ultravariegin demonstrated less bleeding, achieving a 3-to-7-fold wider therapeutic index in rodent thrombosis and bleeding models. When used in combination with aspirin and ticagrelor in a porcine model, variegin/ultravariegin reduced stent thrombosis compared with antiplatelet therapy alone but achieved a 5-to-7-fold lower bleeding time than UFH/bivalirudin. Moreover, two antibodies screened from a naïve human antibody library effectively reversed the anticoagulant activity of ultravariegin, demonstrating proof-of-principle for antidote reversal. Variegin and ultravariegin are promising translational candidates for next-generation DTIs that may reduce peri-PCI bleeding in the presence of antiplatelet therapy.

Practicability of Bivalirudin plus Glycoprotein IIb/IIIa Inhibitors in Patients Undergoing Percutaneous Coronary Intervention: A Meta-Analysis

A variety of antithrombotic drugs are used during percutaneous coronary interventions (PCIs). We aimed to investigate the practicability of the use of bivalirudin and GPIs in patients receiving PCI. We searched 7 of 629 relevant records from PubMed, the Cochrane Library, EMBASE, and Web of Science for randomised controlled trials. There were no significant differences in the rates of major adverse cardiac events (MACE) between bivalirudin plus GPI and heparin (all P  >  .05). Bivalirudin plus planned GPI was similar to bivalirudin monotherapy in terms of the risk of MACE (risk ratio [RR] = 1.07; 95% confidence interval [CI] = .91 − 1.27; P = .55). Bivalirudin plus provisional GPI was associated with lower bleeding risk (RR = .57; 95% CI = .47 − .69; P < .01) compared to using heparin plus GPI. Compared to bivalirudin alone, bivalirudin plus planned GPI evidently increased bleeding risk (RR = 2.20; 95% CI = 1.73 − 2.79; P < .01). Patients receiving bivalirudin or heparin therapy had semblable efficacy endpoints, but those receiving bivalirudin had a significantly lower bleeding risk. For high-risk bleeding patients, bivalirudin plus provisional GPI can have a better antithrombotic effect than heparin, without increasing the bleeding risk.

Reperfusion After Fibrinolytic Therapy (RAFT): An open-label, multi-centre, randomised controlled trial of bivalirudin versus heparin in rescue percutaneous coronary intervention

BACKGROUND

The safety and efficacy profile of bivalirudin has not been examined in a randomised controlled trial of patients undergoing rescue PCI.

OBJECTIVES

We conducted an open-label, multi-centre, randomised controlled trial to compare bivalirudin with heparin ± glycoprotein IIb/IIIa inhibitors (GPIs) in patients undergoing rescue PCI.

METHODS

Between 2010-2015, we randomly assigned 83 patients undergoing rescue PCI to bivalirudin (n = 42) or heparin ± GPIs (n = 41). The primary safety endpoint was any ACUITY (Acute Catheterization and Urgent Intervention Triage Strategy) bleeding at 90 days. The primary efficacy endpoint was infarct size measured by peak troponin levels as a multiple of the local upper reference limit (Tn/URL). Secondary endpoints included periprocedural change in haemoglobin adjusted for red cells transfused, TIMI (Thrombolysis in Myocardial Infarction) bleeding, ST-segment recovery and infarct size determined by the Selvester QRS score.

RESULTS

The trial was terminated due to slow recruitment and futility after an interim analysis of 83 patients. The primary safety endpoint occurred in 6 (14%) patients in the bivalirudin group (4.8% GPIs) and 3 (7.3%) in the heparin ± GPIs group (54% GPIs) (risk ratio, 1.95, 95% confidence interval [CI], 0.52-7.3, P = 0.48). Infarct size was similar between the two groups (mean Tn/URL, 730 [±675] for bivalirudin, versus 984 [±1585] for heparin ± GPIs, difference, 254, 95% CI, -283-794, P = 0.86). There was a smaller decrease in the periprocedural haemoglobin level with bivalirudin than heparin ± GPIs (-7.5% [±15] versus -14% [±17], difference, -6.5%, 95% CI, -0.83-14, P = 0.0067). The rate of complete (≥70%) ST-segment recovery post-PCI was higher in patients randomised to heparin ± GPIs compared with bivalirudin.

CONCLUSIONS

Whether bivalirudin compared with heparin ± GPI reduces bleeding in rescue PCI could not be determined. Slow recruitment and futility in the context of lower-than-expected bleeding event rates led to the termination of this trial (ANZCTR.org.au, ACTRN12610000152022).

A meta-analysis and cost-minimization analysis of bivalirudin versus heparin in high-risk patients for percutaneous coronary intervention

This meta‐analysis was performed to compare the safety, efficacy, and pharmacoeconomic of bivalirudin versus heparin in high‐risk patients for percutaneous coronary interventions (PCI). Earlier meta‐analysis comparing bivalirudin and heparin during PCI demonstrated that bivalirudin caused less bleeding with more stent thrombosis. However, little data were available on the safety of bivalirudin versus heparin in high‐risk patients for PCI. Thus, we performed a meta‐analysis to evaluate the efficacy and safety in the “high‐risk” patients. A systematic search of electronic databases was conducted up to July 30, 2020. The Cochrane Risk of Bias assessment tool was used to assess the quality of included studies. The primary outcomes were all‐cause death and major adverse cardiac events (MACE); secondary outcomes were major and minor bleeding, followed by a cost‐minimization analysis comparing bivalirudin and heparin using a local drug and medical costs reported in China. Subgroup analysis was based on the type of disease of the high‐risk population. Finally, a total of 10 randomized controlled trials involved 42,699 patients were collected. The Cochrane Risk of Bias Tool was employed to appraise the research quality. No significant difference was noted between bivalirudin and heparin regarding all‐cause death and MACE. However, subgroup analysis showed that bivalirudin caused less major bleeding in female (OR:0.65, 95% CI:0.53–0.79), diabetes (OR:0.55, 95%CI:0.42–0.73), and CKD (OR:0.59, 95%CI:0.63–1.65). The scatterers of the included literature were approximately symmetrical, and no research was outside the funnel plot. Additionally, cost‐minimization analysis showed that heparin was likely to represent a cost‐effective option compared with bivalirudin in China, with potential savings of 2129.53 Chinese Yuan (CNY) per patient for one PCI. Overall, the meta‐analysis showed that although bivalirudin appeared to have a lower risk of major bleeding rate, the overall effectiveness and safety between the two groups showed no significant difference in high‐risk patients for PCI. But the results of the cost‐minimization analysis showed that heparin could be a potential cost‐saving drug than bivalirudin in patients for PCI in China.

Stent thrombosis in acute coronary syndromes: Patient-related factors and operator-related factors

OBJECTIVE

Stent thrombosis (ST) is a common phenomenon in acute coronary syndromes (ACS) when compared to stable coronary artery disease. This study analyzed the patient- and operator-related risk factors of ST in ACS.

METHODS

Coronary angiograms of 1738 consecutive ACS patients admitted in a large tertiary center between year 2014 and 2016 were analyzed retrospectively for the presence of ST. The paired angiograms [ST in ACS during and after percutaneous coronary intervention (PCI)] of the patients were analyzed by two independent observers, with focus on lesion characteristics and procedure techniques. Clinical and laboratory data were collected.

RESULTS

Stent thrombosis was found in 29 (1.6%) ACS patients, with a combination of at least one clinical/laboratory risk factor and one lesion/operator risk factor identified in 28 (96%) out of the 29 ACS patients with ST. The following risk factors for ST were found: Renal insufficiency (OR=4.14, p<0.001, 95% CI=1.73-9.88), type 2 diabetes (OR=2.21, p=0.034, 95% CI=1.06-4.61), excessive alcohol consumption (OR=3.12, p=0.023, 95% CI=1.17-8.33), stent implantation for ST-elevation myocardial infarction (STEMI) (OR=2.28, p=0.029, 95% CI=1.08-4.81), left main (LM) or left anterior descending artery (LAD) as culprit lesion (OR=2.80, p=0.010, CI 95%=1.27-5.95), and absence of antiplatelet therapy prior to ST (OR=3.58, p=0.002, 95% CI=1.60-7.96). The following lesion/operator possible risk factors were identified: Bifurcation lesion (n=7; 24%), heavy coronary calcifications (n=13; 44%), in-stent restenosis with secondary plate rupture (n=6, 20%), inappropriate stent size selection (n=6, 20%), and errors in periprocedural drug administration (n=4, 14%).

CONCLUSION

ST occurred in 1/62 ACS patients after PCI. A combination of clinical/laboratory and lesion/operator risk factors were present in almost all ACS patients with ST. This finding may support the search for strictly individualized strategies for the treatment of ACS patients with ST after PCI.

Bivalirudin versus unfractionated heparin during percutaneous coronary intervention in high-bleeding-risk patients with acute coronary syndrome in contemporary practice

BACKGROUND

Bivalirudin, as compared with unfractionated heparin (UFH), has been shown to reduce bleeding complications and supply a better safety profile among low/medium-bleeding-risk patients undergoing percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS) in some previous studies. Whether this advantage persists in patients at high risk of bleeding according to contemporary practice characterized by frequent use of radial-artery access and novel P2Y₁₂ inhibitors, and low use of glycoprotein IIb/IIIa inhibitors (GPIs) is unclear.

AIM OF THE STUDY

This study aimed to assess the efficacy and safety of bivalirudin compared with UFH in high bleeding risk patients with ACS undergoing PCI in current practice.

MATERIALS AND METHODS

All consecutive high-bleeding-risk patients who underwent PCI for ACS at the First Affiliated Hospital of Zhengzhou University from January to September 2019 were retrospectively analyzed. The 30-day primary outcome was a composite of major bleeding, myocardial infarction, all-cause death, or stroke (net adverse clinical events [NACEs]), and the secondary outcomes at 30 days included a composite of myocardial infarction, stoke, or all-cause death (major adverse cardiovascular events [MACEs]), each component of the primary outcome, target vessel revascularization (TVR) and stent thrombosis (ST). Besides, we assessed angina-related health status at 30 days, the length of hospital stay, and hospitalization costs. A logistic regression model was used to adjust for baseline differences. Consistency of the treatment effect of bivalirudin for NACEs and MACEs compared with UFH was evaluated in 15 prespecified subgroups.

RESULTS

From January to September 2019, 823 patients (361 treated with bivalirudin and 462 treated with UFH) were enrolled in the study. GPIs, novel P2Y₁₂ inhibitors, and radial approach was used in 5.6 %, 66.1 %, and 89.7 % of the patients, respectively. After adjusting for baseline differences, bivalirudin was associated with significant reduction in NACEs, MACEs, major bleeding, and myocardial infarction at 30 days compared with UFH. The individual endpoints of death, stroke, ST and TVR did not differ significantly between the 2 groups after adjusting for covariates. Furthermore, bivalirudin consistently reduced the rates of NACEs and MACEs in the 15 prespecified subgroups compared with UFH. These benefits of bivalirudin can translate into improved angina-related health status, shorter hospital stays, and lower hospitalization costs.

CONCLUSIONS

The treatment of bivalirudin showed better efficacy and safety as compared to UFH among patients with ACS undergoing PCI at high risk of bleeding in contemporary practice.

Meta-analysis of bivalirudin versus heparin in transradial coronary interventions

OBJECTIVES

We sought to evaluate the efficacy and safety of bivalirudin versus heparin in patients with coronary artery disease undergoing transradial artery coronary intervention (TRI).

BACKGROUND

Bivalirudin and radial artery access are independently associated with improved cardiovascular outcomes. However, data supporting a strategy of combining both to achieve additive improvements in cardiovascular outcomes provide conflicting results.

METHODS

A systematic search was performed to identify randomized controlled trials (RCTs) of bivalirudin, in which vascular access sites were reported. The primary outcome was net adverse clinical events (NACE) at 30 days. Secondary outcomes were long-term NACE, short-, and long-term major adverse cardiovascular events, all-cause mortality, myocardial infarction, unplanned revascularization, stent thrombosis, and major bleeding.

RESULTS

We identified 10 RCTs, including 16,328 patients who underwent TRI (mean age 64.6 ± 15.7 years, 72.5% male). Bivalirudin use was associated with decreased 30-day NACE compared with heparin (6.3 vs. 7.4%; risk ratio [RR] = 0.87; 95% confidence interval [CI] = 0.76-0.99; p = .04; number needed to treat = 91). No significant interactions were observed based on clinical presentation, administration of P2Y₁₂ inhibitors, or glycoprotein IIb/IIIa-receptor inhibitors (GPI) use. There were no significant differences between groups in any prespecified secondary outcomes. There was, however, a significant reduction of major bleeding in the bivalirudin group compared with heparin when used in combination with routine GPI (RR = 0.41; 95% CI = 0.19-0.90; p = .03).

CONCLUSIONS

Among patients undergoing TRI, use of bivalirudin was associated with significantly reduced 30-day NACE compared with heparin. There was no significant difference in long term NACE, ischemic, or bleeding events compared with heparin.

Value of CHA2DS2-VASc Score for Prediction and Ruling Out of Acute Stent Thrombosis After Primary Percutaneous Coronary Intervention

Acute stent thrombosis is an important complication of stent implantation. The CHA2DS2-VASc (congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, previous stroke, vascular disease, age between 65 and 74 years, female gender) score incorporates important cardiovascular (CV) risk factors and predicts prognosis in various CV conditions. We evaluated the value of the CHA2DS2-VASc score in predicting acute stent thrombosis (ie, thrombosis during 24 hours after stent placement) in patients undergoing primary percutaneous intervention for ST-segment elevated myocardial infarction. Patients with intraprocedural stent thrombosis and complications were excluded; 48 (2.1%) of 2732 patients had acute stent thrombosis according to our definition. Median CHA2DS2-VASc score was significantly higher in this stent thrombosis group. Cumulative acute stent thrombosis rates were 0.51% for CHA2DS2-VASc score ≤1, 1.55% for ≤2, 1.80% for ≤3, 2.00% for ≤4, 2.17% for ≤5, and 2.19% for ≤6. The CHA2DS2-VASc score (odds ratio = 1.390, 95% confidence interval = 1.118-1.728; P = .003) was an independent predictor of acute stent thrombosis. The CHA2DS2-VASc score ≤1 predicted the absence of the acute stent thrombosis with 91% specificity and 36% sensitivity. Further studies are needed to establish the value of this finding in the context of current clinical practice.

Post-Procedural Bivalirudin Infusion at Full or Low Regimen in Patients With Acute Coronary Syndrome

BACKGROUND

The value of prolonged bivalirudin infusion after percutaneous coronary intervention (PCI) in acute coronary syndrome (ACS) patients with or without ST-segment elevation remains unclear.

OBJECTIVES

The purpose of this study was to assess efficacy and safety of a full or low post-PCI bivalirudin regimen in ACS patients with or without ST-segment elevation.

METHODS

The MATRIX program assigned bivalirudin to patients without or with a post-PCI infusion at either a full (1.75 mg/kg/h for ≤4 h) or reduced (0.25 mg/kg/h for ≤6 h) regimen at the operator's discretion. The primary endpoint was the 30-day composite of urgent target-vessel revascularization, definite stent thrombosis, or net adverse clinical events (composite of all-cause death, myocardial infarction, or stroke, or major bleeding).

RESULTS

Among 3,610 patients assigned to bivalirudin, 1,799 were randomized to receive and 1,811 not to receive a post-PCI bivalirudin infusion. Post-PCI full bivalirudin was administered in 612 (ST-segment elevation myocardial infarction [STEMI], n = 399; non-ST-segment elevation acute coronary syndromes [NSTE-ACS], n = 213), whereas the low-dose regimen was administered in 1,068 (STEMI, n = 519; NSTE-ACS, n = 549) patients. The primary outcome did not differ in STEMI or NSTE-ACS patients who received or did not receive post-PCI bivalirudin. However, full compared with low bivalirudin regimen remained associated with a significant reduction of the primary endpoint after multivariable (rate ratio: 0.21; 95% CI: 0.12 to 0.35; p < 0.001) or propensity score (rate ratio: 0.16; 95% CI: 0.09 to 0.26; p < 0.001) adjustment. Full post-PCI bivalirudin was associated with improved outcomes consistently across ACS types compared with the no post-PCI infusion or heparin groups.

CONCLUSIONS

In ACS patients with or without ST-segment elevation, the primary endpoint did not differ with or without post-PCI bivalirudin infusion but a post-PCI full dose was associated with improved outcomes when compared with no or low-dose post-PCI infusion or heparin (Minimizing Adverse Haemorrhagic Events by TRansradial Access Site and Systemic Implementation of angioX [MATRIX]; NCT01433627).

Association between post-percutaneous coronary intervention bivalirudin infusion and net adverse clinical events: a post hoc analysis of the GLOBAL LEADERS study

Aims

The efficacy and safety of continued bivalirudin infusion after percutaneous coronary intervention (PCI) remains uncertain. We sought to investigate the association between post-PCI bivalirudin infusion and the risk of net adverse clinical events (NACE) at 30 days.

Methods and results

In the GLOBAL LEADERS study, all patients who received bivalirudin during PCI were categorized according to the use of bivalirudin infusion after the procedure. The primary endpoint of the present analysis was NACE [a composite of all-cause death, any stroke, any myocardial infarction, all revascularization, and bleeding assessed according to the Bleeding Academic Research Consortium (BARC) criteria Type 3 or 5] at 30 days. The key safety endpoint was BARC Type 3 or 5 bleeding and definite stent thrombosis. Of 15 968 patients, 13 870 underwent PCI with the use of bivalirudin. In total, 7148 patients received continued bivalirudin infusion after procedure, while 6722 patients received standard care. After propensity score covariate adjustment, the risk of NACE did not significantly differ between two treatments after PCI [continued bivalirudin infusion vs. no bivalirudin infusion: 3.2% vs. 3.1%, adjusted hazard ratio (aHR) 1.35, 95% confidence interval (CI) 0.99–1.84, P = 0.06] nor the BARC Type 3 or 5 bleeding (0.7% vs. 0.7%, aHR 0.89, 95% CI 0.44–1.79; P = 0.743) and definite stent thrombosis (0.5% vs. 0.3%, aHR 1.71, 95% CI 0.77–3.81, P = 0.189). However, continued bivalirudin infusion was associated with an increased risk of NACE and definite stent thrombosis in ST-elevation myocardial infarction (STEMI) patients.

Conclusion

In an all-comers population undergoing PCI, there was no significant difference in the risk of NACE at 30 days between continued bivalirudin infusion vs. no bivalirudin infusion after procedure but continued bivalirudin infusion was associated with a higher risk of NACE in STEMI patients when compared with no infusion.

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.

Effect of Short Procedural Duration With Bivalirudin on Increased Risk of Acute Stent Thrombosis in Patients With STEMI: A Secondary Analysis of the HORIZONS-AMI Randomized Clinical Trial

Importance

Bivalirudin has been associated with reduced bleeding and mortality during primary percutaneous coronary intervention for ST-segment elevation myocardial infarction (STEMI). However, increased rates of acute stent thrombosis (AST) have been noted when bivalirudin is discontinued at the end of the procedure, which is perhaps related to this medication's short half-life.

Objectives

To evaluate the clinical effect of procedure duration on AST when either bivalirudin or heparin plus glycoprotein IIb/IIIa receptor inhibitor (GPI) is used.

Design, Setting, and Participants

An ad hoc analysis of the Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction (HORIZONS-AMI) clinical trial was performed between March 1, 2015, and April 30, 2016, on patients who underwent primary percutaneous coronary intervention with stents and were randomized 1:1 to bivalirudin or heparin plus GPI. Defined as the difference between the patient's arrival at the catheterization laboratory and the patient's final angiogram. Participants included 3602 patients with STEMI, aged 18 years or older, who were undergoing primary percutaneous coronary intervention and presenting less than 12 hours from symptom onset.

Main Outcomes and Measures

Clinical events committee-adjudicated definite AST (occurring ≤24 hours after percutaneous coronary intervention).

Results

Among patients included in this analysis, procedure time was identified in 1286 receiving bivalirudin and 1412 receiving heparin plus GPI. Shorter procedures were defined as the lowest quartile of duration (<45 minutes). Patients undergoing shorter procedures were younger and less likely to be hypertensive and smokers. Shorter procedures were less complicated with fewer stents implanted, less multivessel stenting, less thrombus, and less no-reflow. An increased risk of definite AST was associated with shorter than with longer procedures with bivalirudin (7 [2.1%] vs 7 [0.7%]; relative risk, 2.87; 95% CI, 1.01-8.17; P = .04) but not with heparin plus GPI (0 vs 3 [0.3%]; P = .30).

Conclusions and Relevance

Despite less procedural complexity, shorter primary percutaneous coronary intervention time was associated with an increased risk of AST in patients treated with bivalirudin but not patients treated with heparin plus GPI, possibly because of the rapid offset of bivalirudin's antithrombotic effect during a window of limited oral antiplatelet action.

Trial Registration

clinicaltrials.gov Identifier: NCT00433966.

Effects of Bailout Tirofiban on In-Hospital Outcomes and Long-Term Mortality in Patients With ST-Segment Elevation Myocardial Infarction Undergoing Primary Percutaneous Intervention

We retrospectively analyzed short- and long-term outcomes of patients who received bailout tirofiban during primary percutaneous intervention (pPCI). A total of 2681patients who underwent pPCI between 2009 and 2014 were analyzed; 1331 (49.6%) out of 2681 patients received bailout tirofiban. Using propensity score matching, 2100 patients (1050 patient received bail-out tirofiban) with similar preprocedural characteristics were identified. Patients who received bailout tirofiban had a significantly higher incidence of acute stent thrombosis, myocardial infarction, and major cardiac or cerebrovascular events during the in-hospital period. There were numerically fewer deaths in the bailout tirofiban group in the unmatched cohort (1.7% vs 2.5%, P = .118). In the matched cohort, in-hospital mortality was significantly lower (1.1% vs 2.4%, P = .03), and survival at 12 and 60 months were higher (96.9% vs 95.2%, P = .056 for 12 months and 95.1% vs 92.0%, P = .01 for 60 months) in the bailout tirofiban group. After multivariate adjustment, bailout tirofiban was associated with a lower mortality at 12 months (odds ratio [OR]: 0.554, 95% confidence interval [CI], 0.349-0.880, P = .012) and 60 months (OR: 0.595, 95% CI, 0.413-0.859, P = .006). In conclusion, bailout tirofiban strategy during pPCI is associated with a lower short- and long-term mortality, although in-hospital complications were more frequent.

Bivalirudin versus heparin monotherapy in non-ST-segment elevation myocardial infarction

BACKGROUND

The optimal anti-coagulation strategy for patients with non-ST-elevation myocardial infarction treated with percutaneous coronary intervention is unclear in contemporary clinical practice of radial access and potent P2Y12-inhibitors. The aim of this study was to investigate whether bivalirudin was superior to heparin monotherapy in patients with non-ST-elevation myocardial infarction without routine glycoprotein IIb/IIIa inhibitor use.

METHODS

In a large pre-specified subgroup of the multicentre, prospective, randomised, registry-based, open-label clinical VALIDATE-SWEDEHEART trial we randomised patients with non-ST-elevation myocardial infarction undergoing percutaneous coronary intervention, treated with ticagrelor or prasugrel, to bivalirudin or heparin monotherapy with no planned use of glycoprotein IIb/IIIa inhibitors during percutaneous coronary intervention. The primary endpoint was the rate of a composite of all-cause death, myocardial infarction or major bleeding within 180 days.

RESULTS

A total of 3001 patients with non-ST-elevation myocardial infarction, were enrolled. The primary endpoint occurred in 12.1% (182 of 1503) and 12.5% (187 of 1498) of patients in the bivalirudin and heparin groups, respectively (hazard ratio of bivalirudin compared to heparin treatment 0.96, 95% confidence interval 0.78-1.18, p=0.69). The results were consistent in all major subgroups. All-cause death occurred in 2.0% versus 1.7% (hazard ratio 1.15, 0.68-1.94, p=0.61), myocardial infarction in 2.3% versus 2.5% (hazard ratio 0.91, 0.58-1.45, p=0.70), major bleeding in 8.9% versus 9.1% (hazard ratio 0.97, 0.77-1.24, p=0.82) and definite stent thrombosis in 0.3% versus 0.2% (hazard ratio 1.33, 0.30-5.93, p=0.82).

CONCLUSION

Bivalirudin as compared to heparin during percutaneous coronary intervention for non-ST-elevation myocardial infarction did not reduce the composite of all-cause death, myocardial infarction or major bleeding in non-ST-elevation myocardial infarction patients receiving current recommended treatments with modern P2Y12-inhibitors and predominantly radial access.

Bivalirudin versus heparin with primary percutaneous coronary intervention

BACKGROUND

Optimal adjunctive therapy in ST-segment elevation myocardial infarction (STEMI) patients treated with primary PCI (PPCI) remains a matter of debate. Our aim was to compare the efficacy and safety of bivalirudin to unfractionated heparin (UFH), with or without glycoprotein IIb/IIIa inhibitors (GPI) in a large real-world population, using data from the Swedish national registry, SWEDEHEART.

METHOD

From 2008 to 2014 we identified 23,800 STEMI patients presenting within 12 hours from symptom onset treated with PPCI and UFH ± GPI or bivalirudin±GPI. Primary outcomes included 30-day all-cause mortality and major in-hospital bleeding. Multivariable regression models and propensity score modelling were utilized to study adjusted association between treatment and outcome.

RESULTS

Treatment with UFH ± GPI was associated with similar risk of 30-day mortality compared to bivalirudin±GPI (5.3% vs 5.5%, adjusted HR 0.94; 95% CI 0.82-1.07). The adjusted risk for 1-year mortality, 30-day and 1-year stent thrombosis and re-infarction did not differ significantly between UFH ± GPI and bivalirudin±GPI. In contrast, treatment with UFH ± GPI was associated with a significant higher risk of major in-hospital bleeding (adjusted OR 1.62; 95% CI 1.30-2.03). When including GPI use in the multivariable analysis, the difference was attenuated and no longer significant (adjusted OR 1.25; 95% CI 0.92-1.70).

CONCLUSION

Bivalirudin±GPI was associated with significantly lower risk for major inhospital bleeding but no significant difference in 30-day or one year mortality, stent thrombosis or re-infarction compared with UFH ± GPI. The bleeding reduction associated with bivalirudin could be explained by the greater GPI use with UFH.

Antiplatelet and anticoagulation therapy during percutaneous coronary interventions: A review for the interventionalist

Pharmacotherapy for percutaneous coronary interventions is essential to optimize the balance between thrombosis and bleeding. Currently, choices abound for the selection of antiplatelet and anticoagulation therapies during percutaneous intervention (PCI). This review article discusses the mechanisms, pharmacokinetics/dynamics, and clinical data behind the various pharmacotherapies including; aspirin, thienopyridines, glycoprotein IIb/IIIa inhibitors, vorapaxar, heparin, direct thrombin inhibitors, and factor Xa inhibitors.

Bivalirudin versus heparin in percutaneous coronary intervention-a systematic review and meta-analysis of randomized trials stratified by adjunctive glycoprotein IIb/IIIa strategy

Background

Bivalirudin has been shown to be associated with less major bleeding than heparin in patients undergoing percutaneous coronary intervention (PCI); but the confounding effect of concomitant glycoprotein IIb/IIIa inhibitors (GPI) limits meaningful comparison. We performed a systematic review and meta-analysis to compare bivalirudin to heparin, with and without adjunctive GPI in PCI.

Methods

We searched PubMed, Cochrane, EMBASE, CINAHL and WOS from January 2000 to December 2017 for clinical trials comparing bivalirudin to heparin, with and without adjunctive GPI during PCI. Cochrane's Q statistics were used to determine heterogeneity. Random effects model was used.

Results

Twenty-six comparison groups (22 original studies and 4 subgroup analyses) with 53,364 patients were included. Mean follow-up was 192±303 days. There was no difference between the two groups in all-cause mortality [risk ratio (RR: 0.93; 95% CI: 0.82-1.05, P=0.260), target vessel revascularization (TVR) (RR: 1.17; 95% CI: 0.93-1.46, P=0.174) or stroke (RR: 0.91; 95% CI: 0.71-1.18, P=0.490). Major bleeding was lower in the bivalirudin group with concomitant GPI in one or both arms (RR: 0.64; 95% CI: 0.53-0.77, P<0.001) and without (RR: 0.71; 95% CI: 0.51-0.99, P=0.041) provisional or routine GPIs. Bivalirudin appeared to have a higher risk of stent thrombosis (RR: 1.32; 95% CI: 1.04-1.68, P=0.022) and a trend towards more myocardial infarction (RR: 1.12; 95% CI: 0.98-1.28, P=0.098) though without statistical significance. However, exclusion of studies with GPI showed no difference in stent thrombosis or myocardial infarction with bivalirudin.

Conclusions

Bivalirudin is associated with less major bleeding compared to heparin, regardless of GPI use. The lower anticoagulant effect of bivalirudin is linked with higher stent thrombosis and a trend towards more MI, however a confounding effect of GPI use in the heparin arm cannot be excluded.

Acute stent thrombosis: Should preventative measures start in the emergency department?

Stent thrombosis is a potentially life threatening condition caused by several factors or a combination factors, such as resistance to platelet agents and type of anticoagulation used as well as stent types. We report a case of acute thrombosis and discuss potential areas of intervention with literature review.

At least seven days delayed stenting using minimalist immediate mechanical intervention (MIMI) in ST-segment elevation myocardial infarction: the SUPER-MIMI study

AIMS

The aim of this study was to ascertain whether a minimalist immediate mechanical intervention (MIMI) aiming to restore an optimal Thrombolysis In Myocardial Infarction (TIMI) flow in the culprit artery, followed ≥7 days later by a second percutaneous coronary intervention with intentional stenting, is safe in patients with ST-segment elevation myocardial infarction and large thrombotic burden.

METHODS AND RESULTS

SUPER-MIMI was a prospective, observational trial conducted between January 2014 and April 2015 in 14 French centres. A total of 155 patients were enrolled. The pharmacological therapy was left to the operator's discretion. Eighty-one patients (52.3%) had glycoprotein IIb/IIIa inhibitors (GPI) initiated before the end of the first procedure. The median (interquartile range [IQR]) delay between the two procedures was eight (seven to 12) days. Infarct-related artery reocclusion between the two procedures (primary endpoint) occurred in two patients (1.3%), neither of whom received GPI treatment. TIMI flow was maintained or improved between the end of the first procedure and the beginning of the second procedure in all patients. Thrombotic burden and stenosis severity diminished significantly between the two procedures. Stents were ultimately implanted in 97 patients (62.6%).

CONCLUSIONS

Deferred stenting (≥7 days) in patients with a high thrombus burden was safe on a background of GPI therapy.

Incidence, predictors, and clinical outcomes of early stent thrombosis in acute myocardial infarction patients treated with primary percutaneous coronary angioplasty (insights from the University of Ottawa Heart Institute STEMI registry)

BACKGROUND

Early stent thrombosis (ST) remains an important complication of primary percutaneous intervention (PCI). To date, our information on angiographic and clinical predictors of early ST in ST-segment elevation myocardial infarction (STEMI) patients treated with primary PCI is limited.

METHODS

We tried to evaluate the incidence, predictors, and outcomes of early ST in real-world patients treated with primary PCI. We identified all the patients presenting with STEMI between June 2004 and January 2011 who underwent primary PCI as the primary mode of revascularization. Diagnosis of ST was made as per the standard definition proposed by the Academic Research Consortium.

RESULTS

The incidence of early ST was 1% among 2,303 patients treated with primary PCI. Definite and probable early ST occurred in 22 and 2 patients, respectively. Patients with early ST had higher in-hospital (P = 0.03) and 30-day mortality (P = 0.048). The rate of cardiogenic shock (P = 0.0006) and cerebrovascular accident (P = 0.0004) was also greater in the early ST group. Smaller stent diameter and lower use of intracoronary glycoprotein IIb/IIIa inhibitor were associated with higher rate of early ST. There was a trend of higher bivalirudin use in ST group, which did not reach significance (P = 0.07) On IVUS imaging, stent malapposition and uncovered plaque area were noted in 6 out of 11 cases.

CONCLUSION

The incidence of early ST in primary PCI cohort is low. However, it is still associated with higher mortality and morbidity. Small stent diameter and disuse of intracoronary glycoprotein IIb/IIIa inhibitor may be associated with early ST.

Early clinical outcomes as a function of use of newer oral P2Y12 inhibitors versus clopidogrel in the EUROMAX trial

Objective

To ascertain whether different oral P2Y₁₂ inhibitors might affect rates of acute stent thrombosis and 30-day outcomes after primary percutaneous coronary intervention (pPCI).

Methods

The European Ambulance Acute Coronary Syndrome Angiography (EUROMAX) randomised trial compared prehospital bivalirudin with heparin with optional glycoprotein IIb/IIIa inhibitor treatment in patients with ST-segment elevation myocardial infarction triaged to pPCI. Choice of P2Y₁₂ inhibitor was at the investigator’s discretion. In a prespecified analysis, we compared event rates with clopidogrel and newer oral P2Y₁₂ inhibitors (prasugrel, ticagrelor). Rates of the primary outcome (acute stent thrombosis) were examined as a function of the P2Y₁₂ inhibitor used for loading and 30-day outcomes (including major adverse cardiac events) as a function of the P2Y₁₂ inhibitor used for maintenance therapy. Logistic regression was used to adjust for differences in baseline characteristics.

Results

Prasugrel or ticagrelor was given as the loading P2Y₁₂ inhibitor in 49% of 2198 patients and as a maintenance therapy in 59%. No differences were observed in rates of acute stent thrombosis for clopidogrel versus newer P2Y₁₂ inhibitors (adjusted OR 0.50, 95% CI 0.13 to 1.85). After adjustment, no difference was observed in 30-day outcomes according to maintenance therapy except for protocol major (p=0.029) or minor (p=0.025) bleeding and Thrombolysis In Myocardial Infarction minor bleeding (p=0.002), which were less frequent in patients on clopidogrel. Consistent results were observed in the bivalirudin and heparin arms.

Conclusions

The choice of prasugrel or ticagrelor over clopidogrel was not associated with differences in acute stent thrombosis or 30-day ischaemic outcomes after pPCI.

Trial registration number

NCT01087723.

Outcomes in elderly and young patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention with bivalirudin versus heparin: Pooled analysis from the EUROMAX and HORIZONS-AMI trials

BACKGROUND

Since older age is a strong predictor of not only bleeding but also of ischemic events, understanding the risk:benefit profile of bivalirudin in the elderly undergoing primary percutaneous coronary intervention (pPCI) for ST-segment elevation (STEMI) is important. For this, we aim to compare elderly with young patients, who all underwent pPCI for STEMI and randomly received either bivalirudin or heparin.

METHODS

We performed a patient-level pooled analysis (n=5800) of two large randomized trials. A total of 2149 (37.1%) elderly patients (>65 years of age) with STEMI were enrolled and randomly assigned to either bivalirudin or heparin with or without a GPI (control group) before pPCI. Clinical outcomes at 30 days were analyzed.

RESULTS

In elderly patients, bivalirudin significantly reduced non-CABG major bleeding (7.1% vs 10.4%; P<.01), subacute ST (0.4% vs 1.5%; P<.01), and net adverse clinical events (NACE; composite of all-cause mortality, reinfarction, IDR, stroke or protocol-defined non-CABG major bleeding [13.7% vs 17.2%; P=.03]) with comparable rates of stroke, MI, acute ST, or all-cause death, when compared with heparin with or without GPI.

CONCLUSIONS

In a large group of elderly patients enrolled in the EUROMAX and HORIZONS-AMI trials, bivalirudin was associated with lower 30-day rates of non-CABG major bleeding, subacute ST and NACE, with similar 30-day rates of acute ST and mortality.

Characterization of the Average Daily Ischemic and Bleeding Risk After Primary PCI for STEMI

BACKGROUND

The risk of recurrent ischemic and bleeding events after primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI) may not be uniform over time, which may affect the benefit-to-risk ratio of guideline-recommended antithrombotic therapies in different intervals.

OBJECTIVES

This study sought to characterize the average daily ischemic rates (ADIRs) and average daily bleeding rates (ADBRs) within the first year after primary PCI for STEMI.

METHODS

Among 3,602 patients with STEMI who were enrolled in the HORIZONS-AMI (Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction) trial, all ischemic and bleeding events, including recurrent events, were classified according to the timing of their occurrence as acute (≤24 h after PCI), subacute (1 day to 30 days), and late (30 days to 1 year). Patients were treated with aspirin and clopidogrel for the entire year. ADIRs included cardiac death, reinfarction, and definite stent thrombosis. ADBRs included non-coronary artery bypass graft-related Thrombolysis In Myocardial Infarction major and minor bleeding. ADIRs and ADBRs were calculated as the total number of events divided by the number of patient-days of follow-up in each interval assuming a Poisson distribution. Generalized estimating equations were used to test the absolute least square mean differences (LSMD) between ADIRs and ADBRs.

RESULTS

The ADIR and ADBR both exponentially decreased from the acute to the late periods (p < 0.0001). Although there were no significant differences in ADIR and ADBR in the acute phase (LSMD: +0.11%; 95% confidence interval [CI]: -0.35% to 0.58%; p = 0.63), the ADBR was greater than the ADIR in the subacute phase (LSMD: -0.39%; 95% CI: -0.58% to -0.20%; p < 0.0001). In the late phase, the ADIR exceeded the ADBR (LSMD: +1.51%; 95% CI: 1.04% to 1.98%; p < 0.0001).

CONCLUSIONS

After primary PCI, the ADIR and ADBR both markedly decreased over time. Although the rates for bleeding exceeded those for ischemia within 30 days, the daily risk of ischemia significantly exceeded the daily risk of bleeding beyond 30 days, supporting the use of intensified platelet inhibition during the first year after STEMI.

Bivalirudin versus Heparin Monotherapy in Myocardial Infarction

BACKGROUND

The comparative efficacy of various anticoagulation strategies has not been clearly established in patients with acute myocardial infarction who are undergoing percutaneous coronary intervention (PCI) according to current practice, which includes the use of radial-artery access for PCI and administration of potent P2Y₁₂ inhibitors without the planned use of glycoprotein IIb/IIIa inhibitors.

METHODS

In this multicenter, randomized, registry-based, open-label clinical trial, we enrolled patients with either ST-segment elevation myocardial infarction (STEMI) or non-STEMI (NSTEMI) who were undergoing PCI and receiving treatment with a potent P2Y₁₂ inhibitor (ticagrelor, prasugrel, or cangrelor) without the planned use of glycoprotein IIb/IIIa inhibitors. The patients were randomly assigned to receive bivalirudin or heparin during PCI, which was performed predominantly with the use of radial-artery access. The primary end point was a composite of death from any cause, myocardial infarction, or major bleeding during 180 days of follow-up.

RESULTS

A total of 6006 patients (3005 with STEMI and 3001 with NSTEMI) were enrolled in the trial. At 180 days, a primary end-point event had occurred in 12.3% of the patients (369 of 3004) in the bivalirudin group and in 12.8% (383 of 3002) in the heparin group (hazard ratio, 0.96; 95% confidence interval [CI], 0.83 to 1.10; P=0.54). The results were consistent between patients with STEMI and those with NSTEMI and across other major subgroups. Myocardial infarction occurred in 2.0% of the patients in the bivalirudin group and in 2.4% in the heparin group (hazard ratio, 0.84; 95% CI, 0.60 to 1.19; P=0.33), major bleeding in 8.6% and 8.6%, respectively (hazard ratio, 1.00; 95% CI, 0.84 to 1.19; P=0.98), definite stent thrombosis in 0.4% and 0.7%, respectively (hazard ratio, 0.54; 95% CI, 0.27 to 1.10; P=0.09), and death in 2.9% and 2.8%, respectively (hazard ratio, 1.05; 95% CI, 0.78 to 1.41; P=0.76).

CONCLUSIONS

Among patients undergoing PCI for myocardial infarction, the rate of the composite of death from any cause, myocardial infarction, or major bleeding was not lower among those who received bivalirudin than among those who received heparin monotherapy. (Funded by the Swedish Heart-Lung Foundation and others; VALIDATE-SWEDEHEART ClinicalTrialsRegister.eu number, 2012-005260-10 ; ClinicalTrials.gov number, NCT02311231 .).

Controversies in the Management of ST Elevation Myocardial Infarction: Thrombin Inhibition

Anticoagulation is essential in patients with ST elevation myocardial infarction (STEMI) to prevent further thrombosis and to maintain patency of the infarct-related artery after reperfusion. The various anticoagulant medications available for use in patients with STEMI include unfractionated heparin (UFH), low-molecular-weight heparin, fondaparinux, and bivalirudin, a direct thrombin inhibitor. The authors review the current anticoagulation strategies for patients with STEMI undergoing primary percutaneous coronary intervention (PCI), fibrinolysis, or no reperfusion. The authors present the latest evidence and controversies on this topic, with a focus on bivalirudin versus UFH in the setting of primary PCI for STEMI.

Acute Coronary Stent Thrombosis in Modern Era: Etiology, Treatment, and Prognosis

Acute stent thrombosis (AST) is a rare but life-threatening complication of coronary artery stenting. AST remains a challenging task for cardiologists, despite the application of modern procedural techniques and dual-antiplatelet therapy strategies as well as improved understanding of the underlying pathophysiology. This review focuses on the prevalence, risk factors, prognosis, multiple potential underlying pathogenesis, knowledge gaps, and recommends diagnosis and individualized management strategies of AST.

GPIIb-IIIa Receptor Inhibitors in Acute Coronary Syndrome Patients Presenting With Cardiogenic Shock and/or After Cardiopulmonary Resuscitation

BACKGROUND

Data on the use of GPIIb-IIIa receptor inhibitors (GPI) in acute coronary syndrome (ACS) patients presenting with cardiogenic shock and/or after cardiopulmonary resuscitation is sparse. The aim of the study was to establish the possible influence of the adjunctive use of GPI on 30-day and 1-year mortality in these high-risk patients.

METHODS

Acute coronary syndrome patients (261), who presented with cardiogenic shock and/or were cardiopulmonary resuscitated on admission, were analysed. Groups receiving (170 patients) and not receiving (91 patients) GPI were compared regarding 30-day and 1-year mortality.

RESULTS

The unadjusted all-cause 30-day and 1-year mortality were similar in patients receiving GPI and those not receiving GPI [79 patients (46.5%) vs 50 patients (54.9%) at 30 days; ns, 91 patients (53.5%) vs. 55 (61.1%) at 1 year; ns]. After the adjustment for baseline and clinical characteristics, the adjunctive usage of GPI was identified as an independent prognostic factor in lower 30-day mortality (adjusted OR: 0.41; 95%CI: 0.20 to 0.84; p=0.015) and 1-year mortality (HR 0.62; 95%CI 0.39-0.97; p=0.037). Age, left main PCI and major bleeding_, were also identified as independent prognostic factors in worse 30-day and 1-year mortality. In addition, Thrombolysis in Myocardial Infarction (TIMI) flow 0/1 pre-percutaneous coronary intervention (PCI) predicted a worse 1-year outcome. Novel oral P2Y12 receptor antagonists predicted better 30-day and 1-year survival.

CONCLUSION

Our study suggests that the adjunctive usage of GPI may be beneficial in this high-risk group of patients in whom a delayed onset of action of oral antiplatelet therapy would be expected.

Genetic Polymorphism of CYP2C19 and Inhibitory Effects of Ticagrelor and Clopidogrel Towards Post-Percutaneous Coronary Intervention (PCI) Platelet Aggregation in Patients with Acute Coronary Syndromes

Background

The aim of this study was to observe the effects of genetic polymorphism of CYP2C19 on inhibitory effects of ticagrelor (Tic) and clopidogrel (Clo) towards post-percutaneous coronary intervention (PCI) platelet aggregation (IPA) and major cardiovascular events (MACE) in patients with acute coronary syndromes (ACS).

Material/Methods

From August 2013 to March 2014, 166 patients with ACS undergoing PCI were selected. The patients were randomly grouped into the Tic group and the Clo group. IPA was detected by thromboelastography (TEG) at 1 week after taking the pills. Genotyping of CYP2C19 gene was determined by analysis of gene sequence detection. Patients were followed up for 1 month and MACE was observed.

Results

The total IPA in the Clo group was significantly increased compared with the Tic group (P<0.05). The IPAs in the 3 subgroups of Clo group were all significantly increased compared with the 3 subgroups of the Tic group (all P<0.05). MACE was not significantly different between Clo and Tic groups (P>0.05). MACE had no significant difference among the 3 subgroups of the Tic group (P>0.05). MACE in the low metabolism subgroup of the Clo group was significantly increased compared with the fast metabolism subgroup and middle metabolism subgroup of Clo group (P<0.05). MACE was not significant different between the fast metabolism subgroup and the middle metabolism subgroup of the Clo group (P>0.05). MACE in the low metabolism subgroup of the Tic group was significantly decreased compared with the low metabolism subgroup of the Clo group (P<0.05).

Conclusions

Ticagrelor has a better effect on inhibition platelet aggregation than Clopidogrel in ACS patients undergoing PCI.

Antithrombotic therapy before, during and after emergency angioplasty for ST elevation myocardial infarction

The first three hours after symptom onset hold the maximum potential for myocardial reperfusion and salvage in ST-elevation myocardial infarction (STEMI) patients. During this period timely primary percutaneous coronary intervention (PPCI) or, when PPCI is not promptly feasible, pre-hospital administration of fibrinolyis or a glycoprotein IIb/IIIa-inhibitor (GPI) have been shown to restore coronary patency and reperfusion and even result in myocardial infarction (MI) abortion. On the other hand, oral antiplatelet therapy may not yet guarantee sufficient platelet inhibition. Patients presenting after this golden time have less, if any, benefit from an aggressive antithrombotic treatment prior to PPCI. Antithrombotic treatment during primary angioplasty should be tailored on the basis of the coronary thrombotic burden, vascular approach and the patient's risk of bleeding complications. A GPI-based approach may be favourable in patients presenting early with large MI and high thrombus burden, whereas a bivalirudin-based approach without GPI may be preferred in patients with higher bleeding risk. There are no data to support the use of GPI in bailout conditions. The powerful oral P2Y₁₂ inhibitors, prasugrel and ticagrelor, have been clearly shown to prevent stent thrombosis and recurrent ischaemic events after emergency percutaneous coronary intervention in STEMI patients. Open issues remaining are the treatment of patients with high bleeding risk, such as the elderly and those requiring anticoagulation, as well as the duration of dual antiplatelet therapy after STEMI.

Prolonged High-Dose Bivalirudin Infusion Reduces Major Bleeding Without Increasing Stent Thrombosis in Patients Undergoing Primary Percutaneous Coronary Intervention: Novel Insights From an Updated Meta-Analysis

Background

The optimal antithrombotic therapy in patients with ST‐segment‐elevation myocardial infarction undergoing primary percutaneous coronary intervention (PCI) remains a matter of debate. This updated meta‐analysis investigated the impact of (1) bivalirudin (with and without prolonged infusion) and (2) prolonged PCI‐dose (1.75 mg/hg per hour) bivalirudin infusion compared with conventional antithrombotic therapy on clinical outcomes in patients undergoing primary PCI.

Methods and Results

Eligible randomized trials were searched through MEDLINE, EMBASE, Cochrane database, and proceedings of major congresses. Prespecified outcomes were major bleeding (thrombolysis in myocardial infarction major and Bleeding Academic Research Consortium 3–5), acute stent thrombosis, as well as all‐cause and cardiac mortality at 30 days. Six randomized trials (n=17 294) were included. Bivalirudin compared with heparin (+/− glycoprotein‐IIb/IIIa inhibitor) was associated with reduction in major bleeding (odds ratio [OR]: 0.65, 95% CI: 0.48–0.88, P=0.006, derived from all 6 trials), increase in acute stent thrombosis (OR: 2.75, 95% CI: 1.46–5.18, P=0.002, 5 trials), and lower rate of all‐cause mortality (OR: 0.81, 95% CI: 0.67–0.98, P=0.03, 6 trials) as well as cardiac mortality (OR: 0.69, 95% CI: 0.55–0.87, P=0.001, 5 trials). The incidence of acute stent thrombosis did not differ between the prolonged PCI‐dose bivalirudin and comparator group (OR: 0.81, 95% CI: 0.27–2.46, P=0.71, 3 trials), whereas the risk of bleeding was reduced despite treatment with high‐dose bivalirudin infusion (OR: 0.28, 95% CI: 0.13–0.60, P=0.001, 3 trials).

Conclusions

Bivalirudin (with and without prolonged infusion) compared with conventional antithrombotic therapy in ST‐segment‐elevation myocardial infarction patients undergoing primary PCI reduces major bleeding and death, but increases the rate of acute stent thrombosis. However, prolonging the bivalirudin infusion at PCI‐dose (1.75 mg/kg per hour) for 3 hours eliminates the excess risk of acute stent thrombosis, while maintaining the bleeding benefits.

Impact of Escalating Loading Dose Regimens of Ticagrelor in Patients With ST-Segment Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention: Results of a Prospective Randomized Pharmacokinetic and Pharmacodynamic Investigation

OBJECTIVES

The goal of this study was to assess the pharmacokinetic (PK) and pharmacodynamic (PD) profiles of escalating ticagrelor loading dose (LD) regimens in primary percutaneous coronary intervention (PPCI).

BACKGROUND

Patients with ST-segment elevation myocardial infarction undergoing PPCI frequently have suboptimal platelet inhibition in the early hours after ticagrelor LD. The use of high ticagrelor LD regimens has been hypothesized to optimize platelet inhibition in PPCI.

METHODS

This was a prospective, randomized study of escalating ticagrelor LD regimens (180 mg, 270 mg, or 360 mg) in PPCI (N = 52). PK/PD analyses were performed before and 30 min, 1, 2, 4, 8, and 24 h post-LD. PK assessments included exposure to ticagrelor and its metabolite (AR-C124910XX). PD assessments included P2Y12 reaction units (PRU) measured by VerifyNow P2Y12 and platelet reactivity index (PRI) measured by vasodilator-stimulated phosphoprotein (VASP).

RESULTS

Platelet reactivity was elevated during the first 2 h post-LD. There were no differences in PRU between groups during the study time course (p = 0.179). There were no significant differences in PRU levels across groups at all time points, except at 1 h (p = 0.017) where platelet reactivity was lowest with a 270-mg LD. No differences were found between the 180-mg and 360-mg groups (primary endpoint; p > 0.999). High on-treatment platelet reactivity rates were not different across groups, except at 1 hour (p = 0.038). Parallel PD findings were observed with VASP-PRI. PK analysis showed a delay in ticagrelor absorption and generation of AR-C124910XX, irrespective of dose. Although morphine was associated with a delay in ticagrelor PK/PD, it was not an independent predictor of high on-treatment platelet reactivity.

CONCLUSIONS

ST-segment elevation myocardial infarction patients undergoing PPCI frequently exhibit impaired response to ticagrelor in the early hours after drug administration, which cannot be overcome by increasing LD regimens. These PD findings are largely attributed to an impaired PK profile, indicating a delay in drug absorption compared with that reported in stable clinical settings. (High Ticagrelor Loading Dose in STEMI; NCT01898442).