Efthymios N. Deliargyris

Bivalirudin started during emergency transport for primary PCI

BACKGROUND Bivalirudin, as compared with heparin and glycoprotein IIb/IIIa inhibitors, has been shown to reduce rates of bleeding and death in patients undergoing primary percutaneous coronary intervention (PCI). Whether these benefits persist in contemporary practice characterized by prehospital initiation of treatment, optional use of glycoprotein IIb/IIIa inhibitors and novel P2Y12 inhibitors, and radial-artery PCI access use is unknown. METHODS We randomly assigned 2218 patients with ST-segment elevation myocardial infarction (STEMI) who were being transported for primary PCI to receive either bivalirudin or unfractionated or low-molecular-weight heparin with optional glycoprotein IIb/IIIa inhibitors (control group). The primary outcome at 30 days was a composite of death or major bleeding not associated with coronary-artery bypass grafting (CABG), and the principal secondary outcome was a composite of death, reinfarction, or non-CABG major bleeding. RESULTS Bivalirudin, as compared with the control intervention, reduced the risk of the primary outcome (5.1% vs. 8.5%; relative risk, 0.60; 95% confidence interval [CI], 0.43 to 0.82; P=0.001) and the principal secondary outcome (6.6% vs. 9.2%; relative risk, 0.72; 95% CI, 0.54 to 0.96; P=0.02). Bivalirudin also reduced the risk of major bleeding (2.6% vs. 6.0%; relative risk, 0.43; 95% CI, 0.28 to 0.66; P<0.001). The risk of acute stent thrombosis was higher with bivalirudin (1.1% vs. 0.2%; relative risk, 6.11; 95% CI, 1.37 to 27.24; P=0.007). There was no significant difference in rates of death (2.9% vs. 3.1%) or reinfarction (1.7% vs. 0.9%). Results were consistent across subgroups of patients. CONCLUSIONS Bivalirudin, started during transport for primary PCI, improved 30-day clinical outcomes with a reduction in major bleeding but with an increase in acute stent thrombosis. (Funded by the Medicines Company; EUROMAX ClinicalTrials.gov number, NCT01087723.).

Anti-Platelet Factor 4/Heparin Antibodies An Independent Predictor of 30-Day Myocardial Infarction After Acute Coronary Ischemic Syndromes

Background—We postulated that antibodies to platelet factor 4/heparin complex might contribute to recurrent ischemic events in patients with acute coronary syndrome. Methods and Results—We analyzed serum from patients enrolled in the placebo/unfractionated heparin arm of the GUSTO IV-ACS trial who had high likelihood of prior heparin exposure. We selected 109 patients without thrombocytopenia with the 30-day primary end point (death, myocardial infarction [MI], or revascularization) and 109 age-, gender-, and race-matched controls who did not achieve the primary end point. An ELISA for anti-platelet factor 4/heparin antibodies was performed using 48-hour serum samples. The analyses were done by blinded investigators, and the results were correlated with clinical outcomes. Twenty-three of 218 patients (10.6%) had anti-PF4/heparin antibodies. Patients with anti-PF4/heparin antibodies were more likely to have death or MI (30.4% versus 11.3%, P =0.011) or MI (21.7% versus 6.2%, P =0.008) than patients who were negative for the antibody. After multiple logistic regression analysis, anti-PF4/heparin antibodies remained a predictor of 30-day death or MI (odds ratio, 4.0; 95% CI, 1.4 to 11.3;P =0.0093) and MI (odds ratio, 4.6; 95% CI, 1.4 to 15.0;P =0.0108). The antibody was not associated with the composite end point (death, MI, or revascularization) or with death or revascularization alone. Conclusions—Antibodies to the platelet factor 4/heparin complex are a novel, independent predictor of myocardial infarction at 30 days in patients presenting with acute coronary ischemic syndromes. This finding may explain the previous association between thrombocytopenia and adverse events in patients with acute coronary syndrome and may have important implications for the choice of anticoagulant regimens.

Bivalirudin is superior to heparins alone with bailout GP IIb/IIIa inhibitors in patients with ST-segment elevation myocardial infarction transported emergently for primary percutaneous coronary intervention: a pre-specified analysis from the EUROMAX trial

Aims In the HORIZONS trial, in-hospital treatment with bivalirudin reduced bleeding and mortality in primary percutaneous coronary intervention (PCI) compared with heparin and routine glycoprotein IIb/IIIa inhibitors (GPI). It is unknown whether this advantage of bivalirudin is observed in comparison with heparins only with GPI used as bailout. Methods and results In the EUROMAX study, 2198 patients with ST-segment elevation myocardial infarction (STEMI) were randomized during transport for primary PCI to bivalirudin or to heparins with optional GPI. Primary and principal outcome was the composites of death or non-CABG-related major bleeding at 30 days. This pre-specified analysis compared patients receiving bivalirudin (n = 1089) with those receiving heparins with routine upstream GPI (n = 649) and those receiving heparins only with GPI use restricted to bailout (n = 460). The primary outcome death and major bleeding occurred in 5.1% with bivalirudin, 7.6% with heparin plus routine GPI (HR 0.67 and 95% CI 0.46–0.97, P = 0.034), and 9.8% with heparins plus bailout GPI (HR 0.52 and 95% CI 0.35–0.75, P = 0.006). Following adjustment by logistic regression, bivalirudin was still associated with significantly lower rates of the primary outcome (odds ratio 0.53, 95% CI 0.33–0.87) and major bleeding (odds ratio 0.44, 95% CI 0.24–0.82) compared with heparins alone with bailout GPI. Rates of stent thrombosis were higher with bivalirudin (1.6 vs. 0.6 vs. 0.4%, P = 0.09 and 0.09). Conclusion Bivalirudin, started during transport for primary PCI, reduces major bleeding compared with both patients treated with heparin only plus bailout GPI and patients treated with heparin and routine GPI, but increased stent thrombosis.

Acute Stent Thrombosis After Primary Percutaneous Coronary Intervention : Insights From the EUROMAX Trial (European Ambulance Acute Coronary Syndrome Angiography)

OBJECTIVES This study sought to determine clinical, procedural, and treatment factors associated with acute stent thrombosis (AST) in the EUROMAX (European Ambulance Acute Coronary Syndrome Angiography) trial. BACKGROUND Bivalirudin started during transport for primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction significantly reduced major bleeding compared with heparin with or without glycoprotein IIb/IIIa inhibitors (GPI), but it was associated with an increase in AST. METHODS We compared patients with (n = 12) or without AST (n = 2,184) regarding baseline, clinical, and procedural characteristics and antithrombotic treatment strategies (choice of P2Y12 inhibitor, post-primary PCI bivalirudin infusion dose [0.25 mg/kg/h, or BIV-LOW] vs. [1.75 mg/kg/h, or BIV-PCI] vs. heparin ± GPI). Logistic regression was performed to identify independent correlates of AST. RESULTS The overall AST rate was 0.6% and was higher with bivalirudin than with heparin ± GPI (1.1% vs. 0.2%; p = 0.007). Median time to AST was 2.3 h (interquartile range: 1.9 to 2.8 h). Patients with AST had less hypertension (2 of 14 [14.0%] vs. 961 of 2,182 [44.0%]; p = 0.03), and more frequently received GPI (11 of 14 [78.6%] vs. 880 of 2,183 [40.3%]; p = 0.004). Multivariate analysis using Firth penalized maximum likelihood estimation found hypertension (odds ratio [OR]: 0.24, 95% confidence interval [CI]: 0.07 to 0.92; p = 0.037) and BIV-LOW (OR: 5.8, 95% CI: 1.5 to 22.2; p = 0.010) predictive of AST. Choice of P2Y12 inhibitor had no impact on AST. Compared with heparin ± GPI, AST rates were higher for BIV-LOW (11 of 670 [1.6%] vs. 2 of 947 [0.2%]; p = 0.008), but not different for BIV-PCI (1 of 244 [0.4%]; p = 0.588). CONCLUSIONS In this post-hoc analysis from EUROMAX, AST occurred very early and was not mitigated by the novel P2Y12 inhibitors. Prolonging the bivalirudin infusion at the PCI dose (but not at a lower dose) appeared to mitigate the risk of AST.

Reduction in cardiac mortality with bivalirudin in patients with and without major bleeding: The HORIZONS-AMI trial (Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction).

OBJECTIVES The purpose of this study was to determine whether, in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI), the reduction in cardiac mortality in those taking bivalirudin compared with unfractionated heparin plus a glycoprotein IIb/IIIa inhibitor (UFH+GPI) can be fully attributed to reduced bleeding. BACKGROUND The association between hemorrhagic complications and mortality may explain the survival benefit with bivalirudin. METHODS A total of 3,602 STEMI patients undergoing primary PCI were randomized to bivalirudin versus UFH+GPI. Three-year cardiac mortality was analyzed in patients with and without major bleeding. RESULTS When compared with UFH+GPI, bivalirudin resulted in lower 3-year rates of major bleeding (6.9% vs. 10.5%, hazard ratio [HR]: 0.64 [95% confidence interval (CI): 0.51 to 0.80], p < 0.0001) and cardiac mortality (2.9% vs. 5.1%, HR: 0.56 [95% CI: 0.40 to 0.80], p = 0.001). Three-year cardiac mortality was reduced in bivalirudin-treated patients with major bleeding (20 fewer deaths with bivalirudin; 5.8% vs. 14.6%, p = 0.025) and without major bleeding (18 fewer deaths with bivalirudin; 2.6% vs. 3.8%, p = 0.048). In a fully-adjusted multivariable model accounting for major bleeding and other adverse events, bivalirudin was still associated with a 43% reduction in 3-year cardiac mortality (adjusted HR: 0.57 [95% CI: 0.39 to 0.83], p = 0.003). CONCLUSIONS Bivalirudin reduces cardiac mortality in patients with STEMI undergoing primary PCI, an effect that can only partly be attributed to prevention of bleeding. Further studies are required to identify the nonhematologic benefits of bivalirudin. (Harmonizing Outcomes With Revascularization and Stents in Acute Myocardial Infarction; NCT00433966).

Bivalirudin Versus Heparin Anticoagulation in Transcatheter Aortic Valve Replacement: The Randomized BRAVO-3 Trial.

BACKGROUND Anticoagulation is required during transcatheter aortic valve replacement (TAVR) procedures. Although an optimal regimen has not been determined, heparin is mainly used. Direct thrombin inhibition with bivalirudin may be an effective alternative to heparin as the procedural anticoagulant agent in this setting. OBJECTIVES The goal of this study was to determine whether bivalirudin offers an alternative to heparin as the procedural anticoagulant agent in patients undergoing TAVR. METHODS A total of 802 patients with aortic stenosis were randomized to undergo transfemoral TAVR with bivalirudin versus unfractionated heparin during the procedure. The 2 primary endpoints were major bleeding within 48 h or before hospital discharge (whichever occurred first) and 30-day net adverse clinical events, defined as the combination of major adverse cardiovascular events (all-cause mortality, myocardial infarction, or stroke) and major bleeding. RESULTS Anticoagulation with bivalirudin versus heparin did not meet superiority because it did not result in significantly lower rates of major bleeding at 48 h (6.9% vs. 9.0%; relative risk: 0.77; 95% confidence interval [CI]: 0.48 to 1.23; p = 0.27) or net adverse cardiovascular events at 30 days (14.4% vs. 16.1%; relative risk: 0.89; 95% CI: 0.64 to 1.24; risk difference: -1.72; 95% CI: -6.70 to 3.25; p = 0.50); regarding the latter, the prespecified noninferiority hypothesis was met (pnoninferiority < 0.01). Rates of major adverse cardiovascular events at 48 h were not significantly different (3.5% vs. 4.8%; relative risk: 0.73; 95% CI: 0.37 to 1.43; p = 0.35). At 48 h, the bivalirudin group had significantly fewer myocardial infarctions but more acute kidney injury events than the heparin group; at 30 days, these differences were no longer significant. CONCLUSIONS In this randomized trial of TAVR procedural pharmacotherapy, bivalirudin did not reduce rates of major bleeding at 48 h or net adverse cardiovascular events within 30 days compared with heparin. Although superiority was not shown, the noninferiority hypothesis was met with respect to the latter factor. Given the lower cost, heparin should remain the standard of care, and bivalirudin can be an alternative anticoagulant option in patients unable to receive heparin in TAVR. (International, Multi-center, Open-label, Randomized Controlled Trial in Patients Undergoing TAVR to Determine the Treatment Effect [Both Safety and Efficacy] of Using Bivalirudin Instead of UFH [BRAVO-2/3]; NCT01651780).

Is thrombosis a contributor to heart failure pathophysiology? Possible mechanisms, therapeutic opportunities, and clinical investigation challenges

Thrombotic events (coronary thrombosis, venous thromboembolism, intraventricular thrombosis, intracranial and systemic thromboembolism) occur frequently in patients with heart failure. These events may be precipitated by several mechanisms including hypercoagulability through enhancement of procoagulant reactions, impairment of the protein C pathway, protease activated receptor (PAR) activation, adenosine-mediated thrombosis, or neurohormonal activation; stasis secondary to low cardiac output; and endothelial dysfunction from neurohormonal activation or systemic inflammation. Pathophysiologic evidence and analyses of retrospective data support the hypothesis that antithrombotic agents may improve outcomes in patients with heart failure. Warfarin has not been shown to reduce clinical events in patients with heart failure, although several of the completed randomized trials were underpowered, and the most recent was not placebo-controlled. Many unanswered questions remain that justify continued research in this area. This paper examines the conceptual framework, opportunities, and challenges of clinical investigative approaches with the newer anti-thrombotic agents in patients with heart failure. Critical questions are raised with regard to clinical trial designs that warrant consideration as the field progresses.

Outcomes with cangrelor versus clopidogrel on a background of bivalirudin: insights from the CHAMPION PHOENIX (A Clinical Trial Comparing Cangrelor to Clopidogrel Standard Therapy in Subjects Who Require Percutaneous Coronary Intervention [PCI]).

OBJECTIVES The aim of this study was to examine the efficacy and bleeding outcomes of cangrelor in patients in the CHAMPION PHOENIX (A Clinical Trial Comparing Cangrelor to Clopidogrel Standard Therapy in Subjects Who Require Percutaneous Coronary Intervention [PCI]) who underwent percutaneous coronary intervention with bivalirudin. BACKGROUND Cangrelor is a potent intravenous P2Y12 inhibitor with rapid onset and offset. In the CHAMPION PHOENIX, cangrelor compared with clopidogrel significantly reduced 48-h ischemic events including stent thrombosis, without increasing major bleeding. Bivalirudin has demonstrated ischemic outcomes similar to those with heparin plus glycoprotein IIb/IIIa inhibition, with reduced bleeding but increased early stent thrombosis. METHODS In the modified intent-to-treat population, 2,059 patients (18.8%) received bivalirudin, with 1,014 patients in the cangrelor treatment arm and 1,045 in the clopidogrel treatment arm. RESULTS At 48 h, the primary endpoint of death, myocardial infarction, ischemia-driven revascularization, or stent thrombosis was lower with cangrelor versus clopidogrel (48 [4.7%] vs. 70 [6.7%]; odds ratio [OR]: 0.68, p = 0.047). Death was similar in both arms (2 [0.2%] vs. 2 [0.2%]). Myocardial infarction was reduced by cangrelor (37 [3.6%] vs. 59 [5.6%]; OR: 0.63, p = 0.03), as was death/myocardial infarction (39 [3.8%] vs. 61 [5.8%]; OR: 0.65, p = 0.04). Cangrelor was associated with a nonsignificant trend toward less stent thrombosis (7 [0.7%] vs. 15 [1.4%]; OR: 0.48, p = 0.10), which was evident within 2 h after percutaneous coronary intervention (p = 0.057). GUSTO (Global Use of Strategies to Open Occluded Arteries) severe bleeding was similar in both arms (2 of 1,021 [0.2%] vs. 2 of 1,055 [0.2%]) as were other bleeding definitions and transfusions. Efficacy and safety results were consistent in patients with stable angina, non-ST-segment elevation acute coronary syndrome, and ST-segment elevation myocardial infarction (p for interaction: 0.62 and 0.29). CONCLUSIONS Cangrelor may offer an attractive benefit risk profile when used in combination with bivalirudin.

Current periprocedural anticoagulation in transcatheter aortic valve replacement: could bivalirudin be an option? Rationale and design of the BRAVO 2/3 studies

Transcatheter aortic valve replacement (TAVR) is considered an important option in the management of patients with critical aortic valve stenosis that are either inoperable or have a high surgical risk. Despite continued advances in the procedural aspects of TAVR and decreasing complications rates, the risks of major vascular complications and stroke remain significant, which may in turn confer worse clinical outcomes and impact morbidity and mortality. In this review, we outline certain limitations of the currently recommended periprocedural anticoagulation in TAVR, namely unfractionated heparin that is guided by activated clotting times and protamine use if the bleeding risk is high. We will explore the potential for bivalirudin in this setting, which has become a frontrunner in acute coronary syndrome management because of favorable pharmacokinetics and lower bleeding complications. Finally, we will describe an ongoing large multicenter multinational trial that compares intravenous bivalirudin to unfractionated heparin during TAVR procedures using standardized clinical endpoints.

Bivalirudin Versus Heparin Plus a Glycoprotein IIb/IIIa Inhibitor in Patients With Non–ST-Segment Elevation Myocardial Infarction Undergoing Percutaneous Coronary Intervention After Clopidogrel Pretreatment Pooled Analysis from the ACUITY and ISAR-REACT 4 Trials

Background—The optimal antithrombotic therapy for patients with non–ST-segment elevation myocardial infarction undergoing percutaneous coronary intervention is not well defined. We investigated the efficacy and safety of bivalirudin versus heparin plus a glycoprotein IIb/IIIa inhibitor (GPI) in patients with non–ST-segment elevation myocardial infarction undergoing percutaneous coronary intervention after clopidogrel pretreatment. Methods and Results—This study included 3798 clopidogrel-pretreated patients with non–ST-segment elevation myocardial infarction undergoing percutaneous coronary intervention, who were randomly assigned to receive bivalirudin (n=1928) or heparin (unfractionated heparin or enoxaparin; n=1870) plus a GPI in the setting of the Acute Catheterization and Urgent Intervention Triage Strategy (ACUITY) and Intracoronary Stenting and Antithrombotic Regimen: Rapid Early Action for Coronary Treatment (ISAR-REACT) 4 trials. Major end points were a composite of death, recurrent myocardial infarction or urgent target vessel revascularization (efficacy end point), major bleeding (safety end point), and the composite of death, recurrent myocardial infarction, urgent target vessel revascularization, or major bleeding (net adverse clinical events [NACE]) at 30 days. The incidence of the efficacy end point was 10.6% (n=205) in the bivalirudin group versus 10.2% (n=191) in the heparin plus a GPI group (OR, 1.04; 95% CI, 0.85–1.27; P=0.69). The incidence of safety end point was 3.4% (n=66) in the bivalirudin group versus 6.3% (n=117) in the heparin plus a GPI group (OR, 0.54 [0.40–0.72]; P<0.001). NACE occurred in 258 patients (13.4%) in the bivalirudin group versus 275 patients (14.7%) in the heparin plus a GPI group (OR, 0.90 [0.76–1.06]; P=0.21). Conclusions—NACE rates were not significantly different between bivalirudin and heparin plus a GPI in patients with non–ST-segment elevation myocardial infarction undergoing percutaneous coronary intervention after clopidogrel pretreatment. Although no significant difference in efficacy was seen in terms of suppression of adverse ischemic events, bivalirudin was superior to heparin plus a GPI in terms of reducing bleeding events. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique Identifier: NCT00093158 and NCT00373451.