Reversible P2Y12 inhibitor versus irreversible P2Y12 inhibitor in ACS patients undergoing PCI (the acute coronary syndrome israeli survey (ACSIS)

Introduction

Based on data from randomized controlled trials, both American and European guidelines recommend treating acute coronary syndrome (ACS) patients with second generation P2Y12 inhibitors.1,2 Direct head-to-head comparison of these agents was scarce until the recent publication of the ISAR-REACT-5 study which demonstrated the superiority of the Irreversible thienopyridine type P2Y12 inhibitor (prodrug) over the reversible P2Y12 inhibitor in terms of 1-year composite of death, myocardial infarction (MI), and stroke.3,4,5 Given the unexpected outcomes of this trial, we sought to perform a comparison of ticagrelor and prasugrel in real-life ACS patients.

Purpose

To compare the outcomes of ACS (acute coronary syndrome) patients undergoing in-hospital PCI (percutaneous coronary intervention) treated with the Irreversible thienopyridine type P2Y12 inhibitor (prodrug) versus the reversible P2Y12 inhibitor.

Methods

ACSIS (Acute Coronary Syndrome in Israel) is a national ACS snapshot survey conducted in all 25 cardiology departments in Israel since 2000 over a two-month period, every two to three years. Both the Irreversible thienopyridine type P2Y12 inhibitor (prodrug) and the reversible P2Y12 inhibitor were commercially introduced in Israel in 2010. We therefore considered patients enrolled in ACSIS surveys 2010–2018 for the present analysis.

Results

Among 7,233 patients enrolled to the ACSIS (Acute Coronary Syndrome in Israel) registry between 2010 and 2018, we identified 1133 eligible patients treated with the Irreversible thienopyridine type P2Y12 inhibitor (prodrug) and 825 with the reversible P2Y12 inhibitor. In hospital complication rates, including rates of stent thrombosis, were roughly similar between groups. Compared to the reversible P2Y12 inhibitor, the Irreversible thienopyridine type P2Y12 inhibitor (prodrug) was associated with lower 1-year death in ST-elevation myocardial infarction (STEMI) patient compared to non-ST-elevation ACS (NSTE-ACS) patients (p for interaction 0.03). In propensity score matched STEMI patients (502 receiving the Irreversible thienopyridine type P2Y12 inhibitor (prodrug), 251 the reversible P2Y12 inhibitor) 30-day re-hospitalization rate (p<0.05), 30-day MACE (the composite of death, MI, stroke, urgent revascularization; p=0.006), and 1-year mortality rates (p=0.08) were higher in the the reversible P2Y12 inhibitor group compared to the the Irreversible thienopyridine type P2Y12 inhibitor (prodrug) group; In NSTE-ACS patients, outcomes were not impacted by drug choice.

Conclusion

The Irreversible thienopyridine type P2Y12 inhibitor (prodrug) was more effective than the reversible P2Y12 inhibitor in STEMI patients, but not in NSTE-ACS patients.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): the Israeli working group on acute cardiac care of the Israel heart society

Apixaban versus Warfarin in Patients with Left Ventricular (LV) Thrombus, a prospective randomized trial

Background

Patients with acute myocardial infarction (MI) have an elevated risk of stroke, mostly due to left ventricular (LV) thrombus formation, which typically occur within the first 2 weeks following an anterior MI. Currently the recommended management of LV thrombus after acute MI is anticoagulation with vitamin K antagonist. To date, there are no prospective data on the use of direct oral anticoagulants (DOACS) for stroke prevention in the setting of LV thrombus.

Aim

To assess the efficacy of apixaban vs. warfarin in treating LV thrombus after MI.

Methods

The study is a prospective, randomized, multi-center open label trial comparing apixaban (at a dose of 5 mg twice daily) with s.c enoxaparin 1mg/kg BID followed by dose-adjusted warfarin to achieve a target international normalized ratio (INR) of 2.0 to 3.0 for 3 months in patients with LV thrombus detected by echocardiography 3 to 14 days after acute MI. The primary outcome was the presence and size of LV thrombus 3 months after initiation of anticoagulation as assessed by 2D echocardiogram. Secondary outcomes were stroke or systemic embolism, major bleeding and death from any cause.

Results

25 patients have been enrolled to date in 3 medical centers, 13 were randomized to apixaban and 12 to warfarin. Mean age was 59.8±10.7 and 19 (76%) were males with no difference between the study groups. Mean LV thrombus size at enrollment was 24X15 mm in the apixaban group and 19X14 in the warfarin group (p=NS). After 3 months of treatment thrombus completely resolved in all patients in the warfarin group and in 12 of 13 in the apixaban group. In one patient in the apixaban group who had a very large thrombus of 40x20mm size upon enrollment the thrombus size was reduced significantly to 20x12 after 3 months. No death, stroke or systemic embolism was documented in either group. There were two patients with major bleeding in the warfarin group, one had sub-arachnoid hemorrhage after 2 months and anticoagulation was stopped, and another had GI bleeding after 1 month and was switched to enoxaparin. One patient in the warfarin group refused to continue the treatment after 3 weeks. No major bleeding events were recorded in the apixaban group and all patients completed 3 months of treatment.

Conclusions

Our preliminary results indicate that apixaban is a safe and effective treatment for patients with LV thrombus post anterior wall MI.

Funding Acknowledgement

Type of funding source: None

Adaptive response to hypoxia and remote ischaemia pre-conditioning: a new hypoxia-inducible factors era in clinical medicine

Transient ischaemia leads to tolerance to subsequent protracted ischaemia. This 'ischaemia pre-conditioning' results from the induction of numerous protective genes, involved in cell metabolism, proliferation and survival, in antioxidant capacity, angiogenesis, vascular tone and erythropoiesis. Hypoxia-inducible factors (HIF) play a pivotal role in this transcriptional adaptive response. HIF prolyl hydroxylases (PHDs), serving as oxygen sensors, control HIFα degradation. HIF-mediated ischaemic pre-conditioning can be achieved with the administration of PHD inhibitors, with the attenuation of organ injury under various hypoxic and toxic insults. Clinical trials are currently under way, evaluating PHD inhibitors as inducers of erythropoietin. Once their safety is established, their potential use might be further tested in clinical trials in various forms of acute ischaemic and toxic organ damage. Repeated transient limb ischaemia was also found to attenuate ischaemic injury in remote organs. This 'remote ischaemic pre-conditioning' phenomenon (RIP) has been extensively studied recently in small clinical trials, preceding, or in parallel with an abrupt insult, such as myocardial infarction, cardiac surgery or radiocontrast administration. Initial results are promising, suggesting organ protection. Large-scale multi-centre studies are currently under way, evaluating the protective potential of RIP in cardiac surgery, in the management of myocardial infarction and in organ transplantation. The mechanisms of organ protection provided by RIP are poorly understood, but HIF seemingly play a role as well. Thus, Inhibition of HIF degradation with PHD inhibitors, as well as RIP (in part through HIF), might develop into novel clinical interventions in organ protection in the near future.