An Efficacy and Outcome Study of Supplemental Oxygen Treatment in Patients With Suspected Myocardial Infarction (DETO₂X-AMI)

• 1-year all-cause mortality [ Time Frame: 1 year ] [ Designated as safety issue: No ]
  1-year all-cause mortality on an intention to treat basis (ITT)
  
  

• Myocardial damage [ Time Frame: Participants will be followed for the duration of hospital stay, an expected average of 3-5 days ] [ Designated as safety issue: No ]
  Myocardial damage assessed by cardiac resonance imaging (CMR), by electrocardiogram, biomarkers and coronary angiography using the index of microvascular resistance (IMR)
  
  
• Mortality and morbidity [ Time Frame: Participants will be followed for the duration of hospital stay, an expected average of 3-5 days, at 30 days and 1-year ] [ Designated as safety issue: No ]
  Evaluate mortality during hospital stay, at 30 days and 1-year.
  
  
• Heart failure evaluation [ Time Frame: Participants will be followed for the duration of hospital stay, an expected average of 3-5 days ] [ Designated as safety issue: No ]
  Assessment of the degree of heart failure by echocardiography, biomarkers and number of patients needing medical (iv-drugs such as furosemide, nitroglycerine or inotropes) and/or mechanical (CPAP) assistance.
  
  
• Health economics [ Time Frame: Health economics will be assessed from first contact with the ambulance service through to the duration of hospital stay, an expected average of 3-5 days ] [ Designated as safety issue: No ]
  Health economics concerning supplemental oxygen treatment from prehospital contact of the emergency service through to hospital discharge
  
  

AIM:

The aim of the DETO₂X-AMI trial is to evaluate the role of supplemental oxygen delivery in the setting of acute coronary syndrome myocardial infarction including ST-segment elevation myocardial infarction (STEMI), non ST-segment elevation myocardial infarction (NSTEMI) and unstable angina (UA).

DESIGN:

DETO₂X-AMI is a multicentre, interventional, controlled, randomized registry based clinical trial (RRCT) recruiting 6600 patients at cardiac care facilities which report into the SWEDEHEART registry throughout the whole of Sweden.

The SWEDEHEART (Swedish Web-system for Enhancement and Development of Evidence-based care in Heart disease Evaluated According to Recommended Therapies) registry is a nationwide used platform allowing a broad population of all-comers access to the broad registry network which includes:

• RIKS-HIA (nationwide registry where all ischemia cases treated on cardiac intensive care units are registered),
• SCAAR (Swedish Coronary Angiography and Angioplasty Registry where nationwide all coronary angiography and percutaneous coronary intervention (PCI) procedures are registered))
• SEPHIA (nationwide registry for all post AMI follow-up).

All follow-up will be carried out in SWEDEHEART and other national registries such as the national death origin registry (dödsorsaksregister) or the in-patient care registry (slutenvårdsregister). A similar set-up has been successfully used for the TASTE (Thrombus Aspiration in ST-Elevation myocardial infarction in Scandinavia)trial.

MATERIAL and METHODS:

Patients with normal oxygen saturation (≥90% on pulse oximeter) presenting to the ambulance service or the emergency department (ED) with classical symptoms suggestive of acute coronary syndrome (ACS) and significant ECG changes or elevated cardiac biomarkers (ED) are evaluated for inclusion. If eligible, oral informed consent is obtained by EMD or ED personnel prior to inclusion. Randomization is carried out on the cardiac intensive care unit using a web-based tool as part of registration directly into the national SWEDEHEART registry.

Patients are randomized to either supplemental oxygen delivered by oxymask® (6 L/min) for 12 hours (min 6 hours) or no supplemental O₂. All patients receive standard care according to international ACS guidelines including acute coronary intervention.

Primary endpoint is 1-year all-cause mortality. Secondary endpoints will furthermore evaluate mortality, complications during hospital stay, heart failure (echocardiography, registry), myocardial damage using cardiac resonance imaging (CMR), electrocardiogram, modern biomarkers and coronary angiography and health economics.

Follow-up is carried out according to clinical post AMI routine which includes a standardized registration in the SWEDEHEART registry. Mortality data is obtained from the national death origin registry which is linked to SWEDEHEART.

CONCLUSION:

There is no conclusive evidence from adequately designed and powered trials supporting the routine administration of supplemental oxygen in the setting of suspected AMI. The DETO₂X-AMI trial is designed to shed light on this important issue and give guidance to future recommendations.