Bivalirudin in contemporary percutaneous coronary intervention for non-ST-segment elevation acute coronary syndromes: what is the current role of platelet glycoprotein IIb/IIIa receptor inhibitor agents?

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

Background

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

Methods

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

Results

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

Conclusion

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

Carotid Intima-Media Thickness as a Cardiovascular Risk Factor and Imaging Pathway of Atherosclerosis

Assessment of carotid intima-media thickness (IMT) has emerged as a simple and noninvasive technique for measuring atherosclerotic burden. Although serum biomarkers have been linked to the risk of developing atherosclerosis, carotid IMT has the theoretical advantage of directly visualizing a final consequence of the disease itself, namely atherosclerosis in the vessel wall. The current widespread application of carotid IMT measurements has been based on the validity, standardization, and reproducibility of the measurement and the evidence that an increased carotid IMT can be regarded as an attractive biomarker of atherosclerosis and of increased cardiovascular risk, potentially useful as a therapeutic target in those at increased cardiovascular risk. The utilization of carotid IMT measurements as a surrogate end point in clinical trials evaluating a specific drug intervention may result in considerably smaller efforts and costs than when using a hard end point such as myocardial infarction, stroke, or death. In addition, the use of carotid IMT measurement as a screening tool in clinical practice in association with traditional risk factors may improve risk classification and decisions regarding therapeutic interventions. However, although carotid IMT may be correlated with clinical outcomes, changes in surrogate end points over time that result from a particular therapy may not necessarily be predictive of future cardiovascular events. Therefore, it is necessary to perform more clinical studies to clearly define the relationship between the modifications in carotid IMT and the changes in cardiovascular events. In an era of economic burden, when there is a clear combination of limited resources with high expense of innovation in drug development, carotid IMT represents a reasonable, worthwhile surrogate trial end point with a history of nearly 30 years of technical progress and clinical research. Current data strongly suggest that carotid IMT will continue to successfully be used as a valuable tool in clinical atherosclerosis research.

Safety and Effectiveness of Bivalirudin in Patients Undergoing Percutaneous Coronary Intervention: A Systematic Review and Meta-Analysis

Recent clinical trials have shown that while bivalirudin exhibits similar efficacy with heparin, it offers several advantages over heparin, such as a better safety profile. We aimed to evaluate the efficacy and safety of bivalirudin use during Percutaneous Coronary Intervention (PCI) in the treatment of angina and acute coronary syndrome (ACS). We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library, PubMed, EMBASE, and Science Direct from January 1980 to January 2016. Randomized controlled trials (RCTs) comparing bivalirudin to heparin during the course of PCI in patients with angina or ACS were included. Outcome measures included all-cause mortality, myocardial infarction, revascularisation, stent thrombosis, stroke, and major bleeding. The selection, quality assessment, and data extraction of the included trials were done independently by four authors, and disagreements were resolved by consensus. Pooled relative risk (RR) estimates and 95% confidence intervals (CIs) were calculated. A total of 12 RCTs involving 44,088 subjects were included. Bivalirudin appeared to be non-superior compared to heparin in reducing all-cause mortality, myocardial infarction, revascularisation, and stroke. Bivalirudin appeared to be related to a higher risk of stent thrombosis when compared to heparin plus provisional use of a glycoprotein IIb/IIIa inhibitor (GPI) at day 30 (RR 1.94 [1.16, 3.24] p < 0.01). Overall, bivalirudin-based regimens present a lesser risk of major bleeding (RR 0.56 [0.44–0.71] p < 0.001), and Thrombolysis In Myocardial Infarction (TIMI) major bleeding (RR 0.56 [0.43–0.73]) compared with heparin-based regimens either with provisional or routine use of a GPI. However, the magnitude of TIMI major bleeding effect varied greatly (p < 0.001), depending on whether a GPI was provisionally used (RR 0.42 [0.34–0.52] p < 0.001) or routinely used (RR 0.60 [0.43 –0.83] p < 0.001), in the heparin arm. This meta-analysis demonstrated that bivalirudin is associated with a lower risk of major bleeding, but a higher risk of stent thrombosis compared to heparin.

Heparin Versus Bivalirudin in Acute Myocardial Infarction: Unfractionated Heparin Monotherapy Elevated to Primary Treatment in Contemporary Percutaneous Coronary Intervention

Bivalirudin, a direct thrombin inhibitor, was developed as an antithrombin agent for patients undergoing percutaneous coronary interventions (PCI) with the hypothesis that it would reduce bleeding complications without compromising the rate of ischemic events compared to heparin plus GP IIb/IIIa inhibitors. Although the cumulative evidence makes a strong argument for the use of bivalirudin rather than heparin plus systematic GP IIb/IIIa inhibitors for the great majority of patients with acute myocardial infarction (AMI) undergoing PCI, the benefit observed with bivalirudin was achieved because of the major bleeding complications with the use of heparin plus GP IIb/IIIa inhibitors. When bivalirudin was compared with unfractionated heparin alone there was no benefit in ischemic complications with a decrease in major bleeding. However, in a recent large randomized controlled trial comparing bivalirudin with unfractionated heparin alone in AMI patients undergoing primary PCI, bivalirudin did not reduce bleeding complications and was associated with higher rates of stent thrombosis, myocardial reinfarction, and repeat revascularization compared with heparin. Moreover, a very recent meta-analysis shed more insights on the utilization of bivalirudin versus heparin regimens during PCI. Findings from this meta-analysis suggest that routine use of bivalirudin offers little advantage over heparin among PCI patients. In a detailed analysis of some randomized trials and observational studies with bivalirudin in AMI patients done by myself and published almost five years ago in this journal, I rendered some reflections on the future widespread use of bivalirudin. “In the setting of PCI in AMI patients, and in the absence of GP IIb/IIIa inhibitors, bivalirudin did not offer any beneficial effect in the incidence of the composite end points when compared with heparin alone. For now, in real world practice, one would probably choose a well known cheaper drug that has already passed the test of time, heparin. There may be reinforcement in the sole utilization of heparin confining GP IIb/IIIa inhibitors and other intravenous antithrombotics to bailout therapy for periprocedural PCI complications in AMI patients”. Therefore, instead of being the beginning of a new era with bivalirudin, it sure is a welcome back to an old friend, heparin. Indeed, after more than two decades, it is always good to welcome back an old friend, unfractionated heparin, as monotherapy and preferred anticoagulant regimen for contemporary PCI in AMI patients.