COVID-19: A double threat to takotsubo cardiomyopathy and spontaneous coronary artery dissection?

Coronavirus disease 2019 (COVID-19) is an ongoing pandemic that has affected millions of individuals worldwide. Prior studies suggest that COVID-19 may be associated with an increased risk for various cardiovascular disorders, such as myocardial injury, arrhythmia, acute coronary syndrome, and venous thromboembolism. Early reports of non-COVID-19 patients have described the concurrence of takotsubo cardiomyopathy (TTC) and spontaneous coronary artery dissection (SCAD). However, the interplay between COVID-19, TTC and SCAD has not been well established. We herein propose two sets of two-hit hypotheses for the development of SCAD and TTC in the context of COVID-19. The first two-hit hypothesis explains the development of SCAD, in which TTC-associated formation of vulnerable coronary substrate serves as the first hit (predisposing factor), and COVID-19-associated inflammation and vascular disruption serves as the second hit (precipitating factor). The second two-hit hypothesis is proposed to explain the development of TTC, in which SCAD-associated formation of vulnerable myocardial substrate serves as the first hit, and COVID-19-associated sympathetic overactivity serves as the second hit. Under this conceptual framework, COVID-19 poses a double threat for the development of SCAD (among patients with underlying TTC) as well as TTC (among patients with underlying SCAD), thereby forming a reciprocal causation. This hypothesis provides a rationale for the joint assessment of TTC and SCAD in COVID-19 patients with pertinent cardiovascular manifestations.

Betrixaban for first-line venous thromboembolism prevention in acute medically ill patients with risk factors for venous thromboembolism.

INTRODUCTION: Compared to other direct oral anticoagulants, betrixaban has a longer half-life, smaller peak-trough variance, minimal renal clearance, and minimal hepatic Cytochrome P (CYP) metabolism. The Acute Medically Ill VTE Prevention with Extended Duration Betrixaban (APEX) trial evaluated the efficacy and safety of extended duration betrixaban compared to standard duration enoxaparin in acutely ill hospitalized patients. Areas covered: This article describes the role of betrixaban in the prevention of venous thromboembolism (VTE) in acutely ill medical patients. This article provides a consolidated summary of the primary APEX study findings as well as prespecified and exploratory substudies. This article also provides a review of the results of studies in which other direct factor Xa inhibitors have been evaluated in an extended duration regimen in this patient population. Expert commentary: While previous agents have demonstrated that extended duration VTE prophylaxis can be efficacious, betrixaban is the first agent to demonstrate efficacy without an increase in major bleeding. The totality of the data from the APEX trial supports extended duration betrixaban for VTE prophylaxis in the acute medically ill patient population. As such, betrixaban has been approved in the USA for extended VTE prophylaxis in at-risk acute medically ill patients.

Effect of Procedure and Coronary Lesion Characteristics on Clinical Outcomes Among Atrial Fibrillation Patients Undergoing Percutaneous Coronary Intervention: Insights From the PIONEER AF-PCI Trial.

OBJECTIVES: This study sought to assess whether there were significant interactions of procedural access strategies and lesion characteristics with bleeding and ischemic events among atrial fibrillation (AF) patients anticoagulated with rivaroxaban or warfarin following a percutaneous coronary intervention. BACKGROUND: Among stented AF patients, the impact of procedural access strategies or lesion characteristics on antithrombotic safety and efficacy outcomes is unclear. METHODS: In the PIONEER AF-PCI (An Open-label, Randomized, Controlled, Multicenter Study Exploring Two Treatment Strategies of Rivaroxaban and a Dose-Adjusted Oral Vitamin K Antagonist Treatment Strategy in Subjects With Atrial Fibrillation Who Undergo Percutaneous Coronary Intervention) trial, 2,124 patients were randomized to 3 groups and followed for 12 months: 1) rivaroxaban 15 mg once daily plus a P2Y12 inhibitor (n = 709); 2) rivaroxaban 2.5 mg twice a day plus dual antiplatelet therapy (DAPT) (n = 709); and 3) dose-adjusted warfarin plus DAPT (n = 706). Kaplan-Meier rates of clinically significant bleeding and major adverse cardiovascular events were compared between treatments stratified by subgroups of procedure type and lesion characteristics. RESULTS: Compared with warfarin, both rivaroxaban regimens consistently reduced clinically significant bleeding across subgroups of radial versus femoral arterial access and by vascular closure device use. Treatment effect of rivaroxaban on major adverse cardiovascular events did not vary when stratified by ischemia-driven revascularization, urgency of revascularization, location of culprit artery, presence of bifurcation lesion, presence of thrombus, type, and length of stent or number of stents (interaction p > 0.05 for all subgroups). CONCLUSIONS: Among stented AF patients requiring long-term oral anticoagulation, there was no effect modification by procedure or lesion characteristics of either clinically significant bleeding or major adverse cardiovascular events. Rivaroxaban-based therapy was superior to warfarin plus DAPT in bleeding outcomes regardless of the type of stent or arterial access during the index coronary revascularization. (A Study Exploring Two Strategies of Rivaroxaban [JNJ39039039; BAY-59-7939] and One of Oral Vitamin K Antagonist in Patients With Atrial Fibrillation Who Undergo Percutaneous Coronary Intervention [PIONEER AF-PCI]; NCT01830543).