The 2025 ACC/AHA/ACEP/NAEMSP/SCAI Guideline for managing patients with acute coronary syndromes (ACS) is the first major update since the 2013-2015 ST-elevation myocardial infarction (STEMI) and non-ST elevated myocardial infarction (NSTEMI) guidelines. It brings both conditions together into a single framework. This review covers the most important new and revised recommendations and points out where evidence is still lacking.

Delayed endothelialization and inflammatory response are two major obstacles that hinder vascular healing by drug-eluting stents (DES). Here, we report a biomimetic nanozyme strategy to address this issue. We first design and anchor a robust glutathione peroxidase (GPx)-biomimetic nanozyme with diselenide-polyphenol networks on a stent. Then, a thrombin inhibitor, bivalirudin, is efficiently loaded onto the nanozyme utilizing its reversible interactions with polyphenol. The nanozymes exhibit potent GPx activity to controllably generate nitric oxide (NO) and on-demand elution of bivalirudin. The synergistic effects of NO and bivalirudin effectively inhibit thrombin activity, prevent platelet activation, and consequently suppress thrombosis as well as the inflammatory response associated with it. In vitro pathological model cell studies demonstrate that the nanozyme-engineered stents specifically inhibit smooth muscle cell (SMC) proliferation, regulate macrophage polarization, and promote the repair and proliferation of endothelial cells. Thus, it enables rapid endothelialization and vascular healing, preventing restenosis in rabbit and swine models.

Managing anticoagulation during pediatric extracorporeal membrane oxygenation (ECMO) remains a persistent clinical challenge due to the narrow margin between life-threatening hemorrhage and thrombotic occlusion. While bivalirudin has gained traction as a promising alternative to unfractionated heparin (UFH) owing to its predictable pharmacokinetics, robust evidence supporting its pediatric efficacy remains limited. This systematic review and meta-analysis compared clinical outcomes between bivalirudin and UFH in pediatric ECMO populations by searching PubMed, Embase, Scopus, Web of Science, Cochrane CENTRAL and CNKI up to April 4, 2026. Twelve studies (including 770 patients) were analyzed using random-effects models. Compared with UFH, bivalirudin may be associated with significantly lower odds of major bleeding (OR 0.20, 95% CI 0.12-0.32), systemic thrombosis (OR 0.42, 95% CI 0.23-0.75), neurologic events (OR 0.47, 95% CI 0.29-0.78), and in-hospital mortality (OR 0.57, 95% CI 0.41-0.79), alongside faster achievement of therapeutic targets. Although ECMO duration was longer with bivalirudin (SMD 0.43, 95% CI 0.11-0.75), no significant differences were observed in circuit thrombosis, on-ECMO mortality, or time within the therapeutic range. Consequently, bivalirudin may provide a safer, more effective anticoagulation strategy than UFH in pediatric ECMO, though prospective multicenter studies and randomized trials are warranted to validate these findings.

Background: Heparin-Induced Thrombocytopenia (HIT) is a serious immune-mediated complication characterized by anti-platelet factor 4 (PF4)/heparin antibodies that activate platelets, causing thrombocytopenia and a paradoxical prothrombotic state. Management requires immediate heparin discontinuation and alternative anticoagulation due to thrombotic risks. Case Presentation: We report a 36-year-old pregnant female with heart failure who developed HIT after heparin exposure during extracorporeal membrane oxygenation (ECMO) support and was subsequently evaluated for heart transplantation. Confirmed HIT led to switching anticoagulation to bivalirudin. Prior to transplantation, where intraoperative heparin is standard, she underwent plasmapheresis (PLEX) followed by intravenous immunoglobulin (IVIG) and corticosteroids to reduce circulating HIT antibodies. This immune-modulating approach enabled safe intraoperative heparin use without thrombotic complications. Post-transplant HIT assays were negative, with platelet recovery and stable coagulation parameters. Discussion: This case demonstrates that combined PLEX and IVIG can effectively lower pathogenic HIT antibodies, permitting necessary heparin administration in critical settings like heart transplantation. Conclusion: Given the lack of standardized guidelines for managing HIT when heparin exposure is unavoidable, this report highlights a promising strategy to mitigate risks and underscores the need for further research to optimize care in such complex clinical scenarios.

Large ascending aortic thrombus can lead to devastating consequences and requires astute recognition and evaluation, systemic anticoagulation, and urgent surgical intervention. Perioperative and surgical management of a large ascending aortic thrombus is further complicated in patients who develop heparin induced thrombocytopenia (HIT) as the risks of further thrombosis and perioperative bleeding must be carefully navigated. We report the case of a patient who presents with multiple thromboses, including a massive ascending aortic mural thrombus, indicative of an underlying hypercoagulable state, who developed acute HIT after systemic anticoagulation and required urgent cardiac surgery for removal of the aortic thrombus. Following stabilization of acute HIT with argatroban, surgical thrombectomy of the large aortic thrombus and endarterectomy of a penetrating aortic ulcer was successfully performed using bivalirudin anticoagulation for cardiopulmonary bypass without complication. Postoperatively the patient was maintained on argatroban followed by transition to outpatient warfarin without new thromboembolic or bleeding complications.