Comparison of effectiveness and safety of three different antithrombotic regimens (bivalirudin, eptifibatide, and heparin) in preventing myocardial ischemia during percutaneous coronary intervention

Meta-Analysis of Effects of Bivalirudin Versus Heparin on Myocardial Ischemic and Bleeding Outcomes After Percutaneous Coronary Intervention

Bivalirudin is an alternative to unfractionated heparin (UFH) anticoagulation during percutaneous coronary intervention. Previously, we have reported clinical benefit on major bleeding in favor of bivalirudin compared with UFH monotherapy but inconclusive results on mortality. Controversial data have been reported in the last 2 years. We conducted an updated meta-analysis including randomized trials and observational studies, which evaluated ischemic and bleeding outcomes for bivalirudin compared with UFH-only during percutaneous coronary intervention. We included 18 observational studies and 12 randomized trials published from 2003 to 2015. Primary outcomes were major adverse cardiovascular events within 30 days including death, myocardial infarction, and urgent revascularization and stent thrombosis, major bleeding, and transfusion. Overall, we found a significant risk reduction with bivalirudin for major bleeding (odds ratio [OR] 0.59, 95% confidence interval [CI] 0.49 to 0.71, p <0.0001) and for transfusion (OR 0.79, 95% CI 0.66 to 0.95, p = 0.01) and similar risk for major adverse cardiovascular events (OR 0.98, 95% CI 0.86 to 1.12, p = 0.80). However, there was a substantial increased risk of stent thrombosis associated with bivalirudin (OR 1.52, 95% CI 1.11 to 2.08, p = 0.009). No impact on mortality was found. Meta-regression analyses on major bleeding suggested that bivalirudin was more effective than UFH at doses >60 IU/kg and independent of radial access. In conclusion, compared with UFH monotherapy, bivalirudin remains associated with less bleeding risk but higher stent thrombosis risk. Further study remains required to define its role in current antithrombotic armamentarium.

Meta-analysis comparing bivalirudin versus heparin monotherapy on ischemic and bleeding outcomes after percutaneous coronary intervention

With femoral access, bivalirudin decreases risks of major bleeding after percutaneous coronary intervention (PCI) and provides better net clinical benefit compared to unfractionated heparin (UFH) plus planned glycoprotein IIb/IIIa inhibitors. Whether this benefit exists compared to UFH monotherapy is less clear. We performed a systematic review and meta-analysis to compare outcomes in patients undergoing transfemoral PCI with UFH or bivalirudin. Randomized trials (n = 3) and observational studies (n = 13) comparing bivalirudin to UFH monotherapy were reviewed. Primary outcomes were 30-day rates of major adverse cardiovascular events (MACEs) including death, myocardial infarction (MI), urgent revascularization, as well as all-cause mortality, MI, major bleeding, and blood transfusion. We collected data from 16 studies involving 32,492 patients undergoing PCI. Most observational studies were performed in the United States, whereas all randomized trials were done in Europe. Compared to UFH monotherapy, bivalirudin was associated with similar risk of MACEs (odds ratios [OR] 0.92, 95% confidence interval [CI] 0.75 to 1.12), a substantial 45% relative decrease in major bleeding (OR 0.55, 95% CI 0.43 to 0.72), and a trend in the decrease of transfusion (OR 0.87, 95% CI 0.70 to 1.08). A decrease in mortality was seen in observational studies (OR 0.62, 95% CI 0.45 to 0.85) but remained inconclusive in randomized trials (OR 0.63, 95% CI 0.20 to 2.01). MI rate was similar with the 2 anticoagulants. In conclusion, in patients undergoing transfemoral PCI, the benefit of bivalirudin over UFH monotherapy is driven by a significant decrease in major bleeding with similar rates of MACE. As PCI practice moves toward other bleeding-avoidance strategies such as the radial approach, future studies should focus on the interaction between anticoagulant strategy and access-site choice.

Bivalirudin with provisional glycoprotein IIb/IIIa inhibitors in patients undergoing primary angioplasty in the setting of cardiogenic shock

In patients undergoing percutaneous coronary intervention (PCI), clinical trials have demonstrated that the use of bivalirudin with provisional glycoprotein IIb/IIIa inhibitors is not inferior to heparin with systematic glycoprotein IIb/IIIa inhibitors on major adverse cardiac events and is associated with lower rates of bleeding in various clinical settings. Patients with cardiogenic shock (CS), however, have been excluded from all pivotal trials. A retrospective analysis of 86 consecutive patients undergoing PCI for acute myocardial infarction complicated by CS in our center from April 2003 to September 2007 was performed. In-hospital death, major adverse cardiac events, and bleeding rates were compared in 37 patients who received bivalirudin with or without glycoprotein IIb/IIIa inhibitors and 49 patients who were treated with heparin and glycoprotein IIb/IIIa inhibitors as anticoagulation management. Baseline demographic, clinical, and biological characteristics were similar in the 2 groups. The in-hospital death rate was significantly lower in the bivalirudin group (5.4 vs 32.7%, p = 0.002). There were no differences in the rate of major hematoma between the bivalirudin group and the heparin group (3 vs 2.6%, p = 0.46). In conclusion, bivalirudin with provisional use of glycoprotein IIb/IIIa inhibitors appears to be a safe and effective anticoagualtion strategy in patients undergoing primary PCI for acute myocardial infarction complicated by CS.

Influence of bivalirudin on tissue factor-triggered coagulation

Bivalirudin, a synthetic analog of the carboxy-terminus of hirudin, is a reversible thrombin inhibitor used during coronary balloon angioplasty. The objective of this study was to evaluate the influence of bivalirudin on thrombin generation. Three in-vitro models (numerical simulations, synthetic coagulation proteome and whole blood) of contact pathway-independent blood coagulation triggered with tissue factor were used in this study. Increasing concentrations of bivalirudin prolong the initiation phase of thrombin generation in a concentration-dependent manner. At subpharmacologic bivalirudin concentrations (0.5-2 micromol/l), total thrombin generation was significantly increased. At a pharmacologic concentration (5 micromol/l), bivalirudin suppressed thrombin generation in the synthetic coagulation proteome; in numerical simulations and contact pathway-inhibited whole blood, no thrombin generation was detected over 1200-2000 s and platelet activation was inhibited by 80%. The addition of a pharmacologic concentration (9 micromol/l) of a naturally occurring protease inhibitor aprotinin in the presence of at least 0.5 micromol/l bivalirudin provided limited enhancement of the bivalirudin inhibitory effect. In conclusion, bivalirudin at pharmacologic concentrations is an efficient inhibitor of thrombin generation, platelet activation and clot formation, which acts not as a modulator but as an 'on-off' switch of blood coagulation.

Percutaneous Coronary Intervention–Related Bleeding Risk Factors in Current Practice

BACKGROUND:

Bleeding is a common and costly complication of percutaneous coronary intervention (PCI). Little is known about the risk factors for bleeding complications.

Objective:

To report our PCI-related observations from a single institution and use the information to establish risk factors for short-term bleeding complications, with special focus on examining the importance of renal function.

METHODS:

A retrospective record review was conducted of the admission of 300 patients grouped according to antithrombotic regimen: unfractionated heparin alone (n = 187), bivalirudin (n = 26), and glycoprotein IIb/IIIa antagonist plus heparin (n = 103). Bleeding and ischemic outcomes were tracked. A model was constructed to predict independent bleeding risk factors.

RESULTS:

Treatment groups differed significantly regarding any bleeding (p = 0.001), minor bleeding (p < 0.001), and length of stay (p = 0.01). Multivariate predictors of any bleeding included antithrombotic regimen, creatinine clearance (Clcr) <30 mL/min, and hypertension. Any bleeding was associated with prolonged length of stay. Major bleeding was predicted by Clcr <30 mL/min and was associated with prolonged length of stay and death. Minor bleeding was predicted only by choice of antithrombotic regimen.

CONCLUSIONS:

The major influences on bleeding risk appeared to be Clcr <30 mL/min and choice of antithrombotic regimen. It is important to note that other markers of renal function, including serum creatinine value and serum creatinine at a cutoff level of 1.5 mg/dL, did not predict bleeding events.

Bivalirudin compared with IIb/IIIa inhibitors in patients with in-stent restenosis undergoing intracoronary brachytherapy

BACKGROUND

Bivalirudin is replacing heparin in percutaneous coronary interventions (PCIs), including vascular brachytherapy (VBT). The aim of the study was to compare bivalirudin with eptifibatide in patients with in-stent restenosis (ISR) undergoing PCI and VBT.

METHODS

One hundred forty-four patients treated with bivalirudin as a single antithrombotic agent were compared with 150 patients treated with eptifibatide. Bivalirudin as a bolus of 0.75 mg/kg followed by 1.75 mg/kg/h infusion until the end of the procedure, and eptifibatide as a double bolus of 180 microg/kg followed by 2 microg/kg/min infusion for 18 h after the procedure were used. The main outcome measures were in-hospital events and 30-day clinical outcomes.

RESULTS

Baseline clinical characteristics were similar except that patients in the eptifibatide group were younger (P=.02) and had more saphenous vein graft lesions (P<.001). Patients in the bivalirudin group had a higher number of lesions in the right coronary artery (P<.001) and a higher number of vessels treated (P<.001). Postprocedure creatinine phosphokinase (CPK)-MB levels were significantly lower in the bivalirudin group (P<.03). In-hospital events showed significantly less minor bleeding (P=.01) and a trend toward lower major bleeding and major adverse cardiac events (MACE) in the bivalirudin group (P=.06). Thirty-day outcomes showed a significantly lower incidence of non-Q-wave myocardial infarction (MI) in the bivalirudin group (P=.004).

CONCLUSION

Bivalirudin, as a single antithrombotic agent during PCI and VBT, is associated with significantly lower postprocedural CPK-MB elevation, minor bleeding complications, 30-day non-Q-wave MI rates, and a trend toward lower major bleeding and in-hospital MACE when compared with eptifibatide.

Bivalirudin: a review

Bivalirudin (Angiomax) is a thrombin-inhibiting oligopeptide that was developed via rational drug design as a hirudin analogue ('hirulog'). Similar to hirudin, it is a bivalent thrombin inhibitor, as its 20-amino acid structure combines a carboxy-terminal region that recognises thrombin's fibrin(ogen)-binding site, and an amino-terminal tetrapeptide that inhibits the active site of thrombin, connected by a tetraglycine spacer. It has certain pharmacological advantages over hirudin, including enzymic metabolism (less dependence on renal clearance) and low immunogenicity (reduced potential for anaphylaxis). Bivalirudin is approved for use in percutaneous transluminal coronary angioplasty (PTCA), and is undergoing active investigation for anticoagulation during cardiac surgery, both 'off-pump' and with cardiopulmonary bypass ('on-pump'). Anecdotal 'off-label' experience for the treatment of heparin-induced thrombocytopenia shows promise.

Bivalirudin versus heparin as an antithrombotic agent in patients who undergo percutaneous saphenous vein graft intervention with a distal protection device

Bivalirudin (Angiomax) is increasingly used as a substitute for heparin in a variety of percutaneous coronary interventions, and data on its usage in saphenous vein graft interventions are limited. This retrospective, observational study evaluated the efficacy and safety of bivalirudin compared with heparin as an antithrombotic regimen in patients who underwent saphenous vein graft intervention with distal protection devices. We found that bivalirudin use is clinically safe and feasible, with fewer vascular and ischemic complications compared with heparin.

Addition of heparin to contrast media is associated with increased bleeding and peripheral vascular complications during percutaneous coronary intervention with bivalirudin and drug-eluting stents

BACKGROUND

Nonionic radiographic contrast media (CM) is reported to be thrombogenic while performing diagnostic or interventional procedures. To avoid thrombosis, heparin is often added to the CM. Bivalirudin, used to replace heparin during percutaneous coronary intervention (PCI), is reported to be associated with reduced bleeding complications. We aimed to evaluate the impact of adding heparin to the CM during PCI in patients (pts) who underwent sirolimus-eluting stent (SES) implantation when bivalirudin was utilized as the sole antithrombotic agent.

METHODS

A total of 664 pts with 756 lesions underwent standard PCI with SES for various coronary artery lesions. Pts were treated with either bivalirudin only (the bivalirudin group; 0.75 mg/kg bolus and 1.75 mg/kg/h infusion, n = 323 pts) or bivalirudin (same dose) plus low-dose heparin added to the CM (the heparin mix group; mean dose = 2101.8+/-882.5 U, n = 341 pts) during PCI. The periprocedural, in-hospital, and 30-day clinical outcomes were compared.

RESULTS

Baseline clinical and angiographic parameters were similar between both groups. Periprocedural, in-hospital, and 1-month clinical outcomes, including thrombotic complications, were similar between the two groups. There was no difference in the periprocedural thrombosis rate between the groups. In the heparin mix group, the overall incidence of hematoma was significantly higher (3.8% vs. 8.5%, P = .01), there was a trend toward higher rates of blood transfusion (2.6% vs. 6.6%, P = .06) and overall vascular complications (0.01% vs. 5.3%, P <.001), including pseudoaneurysm (PSA; 0.0% vs. 2.6%, P = .004), and pts who required surgical repair (0.3% vs. 1.8%, P = .07).

CONCLUSIONS

The routine addition of low-dose heparin to CM during contemporary PCI does not add any protection value and is associated with higher rates of bleeding and vascular complications.

Bivalirudin versus heparin as an antithrombotic agent in patients treated with a sirolimus-eluting stent

Bivalirudin (Angiomax) is increasingly used as a substitute for heparin in a variety of percutaneous coronary interventions. This retrospective, observational study aimed to evaluate the efficacy and safety of bivalirudin compared with heparin as an antithrombotic regimen in patients treated with sirolimus-eluting stents (Cypher) and found that bivalirudin is clinically safe and feasible, with fewer vascular and ischemic complications compared with heparin.