Antibiotics vs Surgical ThERapy for Infective endocarditis (ASTERIx)

Study design

Multicenter, multinational, randomized, prospective study.

About the project

Infective endocarditis is a life-threatening disease with increasing incidence. In spite of improved disease-management and diagnostics (i.e. antibiotics, surgery, and imaging techniques) infective endocarditis remains a condition that is hard to diagnose and associated with high mortality (≈1/3 die within one year) and severe complications. Much attention has been given to when, where, and in whom cardiac surgery is associated with better outcomes.

Data on the clinical benefit of surgery over medical therapy in endocarditis are varying in quality, results, and inference. Clinical guidelines on surgical indications have remained quite stable in the past decades encouraging surgery. However, these recommendations are not based on relevant data and at the moment we are putting very sick patients with endocarditis through high-risk procedures without the proper knowledge and perhaps we refrain from surgery where benefit may be likely.


The aim of this study is to test whether surgery is superior to medical therapy for patients with endocarditis with a non-emergent indication for surgery in a randomized trial. This is especially important as endocarditis patients often have many comorbidities and higher operative risk.


In total, 496 patients will be included in the study over four years. The study is event-driven and will require at least 240 events. The study will assess the primary composite outcome of death, embolization, relapse of infective endocarditis, new heart failure or reinfection.

Study participants who survive to discharge will be followed by routine clinical check-ups at one- and four-weeks post-discharge and at three months. Additionally a 12-month study follow-up is planned. The investigators will also conduct a small substudy to assess the frequency of silent emboli.

Project group

  • Emil Loldrup Fosbøl (Sponsor), Rigshospitalet, Copenhagen, Denmark
  • Jonas A Povlsen, MD PhD, Senior Registrar
    Department of Cardiology, Aarhus University Hospital, Aarhus, Denmark
  • Ivy Susanne Modrau, (German), Associate Professor, Consultant Cardiac Surgeon
    Department of Cardiothoracic and Vascular Surgery,  Aarhus University Hospital, Aarhus, Denmark
  • Kaare Troels Jensen, PhD, Consultant
    Department of Cardiology, Aarhus University Hospital, Aarhus, Denmark
  • Vibeke Guldbrand Rasmussen, PhD, Consultant
    Department of Cardiology, Aarhus University Hospital, Aarhus, Denmark


Participating sites:

  • Herlev and Gentofte Hospital, Denmark
  • Bispebjerg Hospital Amager/Hvidovre Hospital, Denmark
  • Nordsjaellands Hospital, Denmark
  • Roskilde University Hospital, Denmark
  • Odense University Hospital, Denmark
  • Aalborg University Hospital, Denmark
  • Lund University Hospital, Sweden
  • Duke University Hospital, USA


Rigshospitalet; Novo Nordisk Foundation (Borregaard Clinical Ascending Investigator 2020 and Investigator Initiated Clinical Trials Grant); and The Danish Heart Foundation.



Project period

Start: 1 May 2022
End: 1 June 2026


Principal Investigators