Effects of Oxygen Treatment on Mechanisms Involved in Ischemia-reperfusion Injury: A Pilot Study in Healthy Volunteers

Summary

Oxygen treatment is widely used in acutely ill patients. In particular, oxygen treatment is routinely used in acute coronary syndrome (ACS) patients with suspected acute myocardial infarction and variably recommended in ACS-guidelines, despite very limited data supporting a beneficial effect.

Immediate re-opening of the acutely occluded infarct-related bloodvessel via primary percutaneous coronary intervention (PCI) is the treatment of choice to limit ischemic injury in the setting of ST-elevation ACS (STE-ACS). However, the sudden re-initiation of blood flow achieved with primary PCI can give rise to further damage, so-called reperfusion injury. Ischemia and reperfusion associated myocardial injury (IR-injury) involves a wide range of pathological processes. Vascular leakage, activation of cell death programs, transcriptional reprogramming, no reflow phenomenon and innate and adaptive immune activation all contribute to tissue damage, thereby determining the infarct size. The effect of oxygen treatment on these pathological processes, on the extent of IR-injury and the final infarct size in STE-ACS patients has not previously been studied.

ACS is characterized by a systemic inflammation with typical elevations of soluble inflammatory markers as well as changes in white blood cells. The inflammatory reaction might be considered helpful in restoring myocardial tissue structure and function, but on the other hand it might worsen IR-injury by activating various pathological processes. In human experimental studies, Salmonella typhi vaccine has been used to create a standardized model of systemic inflammation and when administered to healthy volunteers the vaccination has not been associated with any adverse events.

In an ongoing register randomized multicentre clinical trial, the DETO2X (Determination of role of oxygen in suspected acute myocardial infarction) study, the effect of oxygen on morbidity and mortality in ACS patients is being investigated. In a substudy of the DETO2X-trial, the investigators have planned to evaluate the effect of oxygen treatment on IR-injury in STE-ACS as assessed by biomarkers reflecting various aspects of the pathological processes involved.

The presented study is an experimental pilot study performed in healthy volunteers with a Salmonella typhi vaccine-induced inflammation with the purpose of studying effects of oxygen treatment on biological systems involved in the pathogenesis of IR- injury.

Conditions

• Myocardial Infarction
• Inflammation
• Acute Coronary Syndrome (ACS)
• Reperfusion Injury

Interventions

BIOLOGICAL

Salmonella typhi vaccine (Typhim Vi®)

A peripheral venous catheter will be inserted. This catheter will be used to collect blood sample during the study day. In addition, peripheral oxygen saturation will be measured by pulse oximetry. After baseline venous blood samples have been collected, all study participants will receive 0.5 mL of the Salmonella typhi vaccine as an intramuscular injection (Typhim Vi®, Sanofi Pasteur MSD, injection solution 25 microgram/0.5 mL) Venous blood samples will be collected at 3, 6 and 8 hours after baseline. After the 8-hour blood sampling, the peripheral venous catheter will be removed and the study day ended.

DRUG

Oxygen (Oxymask®)

As in arm 1. Half an hour after vaccination is administered, oxygen treatment will be initiated at 6 L/min via Oxymask® and continued for 6 hours. During oxygen treatment peripheral oxygen saturation will be measured by pulsoximetry. Venous blood samples will be collected at 3, 6 and 8 hours after baseline. After the 8-hour blood sampling, the peripheral venous catheter will be removed and the study day ended.

DRUG

Atorvastatin

As in arm 1. Half an hour after vaccination is administered, oxygen treatment will be initiated at 6 L/min via Oxymask® and continued for 6 hours. During oxygen treatment peripheral oxygen saturation will be measured by pulsoximetry. A single dose of Atorvastatin 80 mg will be given immediately prior to start of oxygen. Venous blood samples will be collected at 3, 6 and 8 hours after baseline. After the 8-hour blood sampling, the peripheral venous catheter will be removed and the study day ended.

Sponsors & Collaborators

• University Hospital, Linkoeping

  collaborator OTHER

• Karolinska Institutet

  lead OTHER

Principal Investigators

• Lennart Nilsson, MD, PHD · Department of Medical and Health Sciences, Linköping University, and Department of Cardiology, University Hospital, 58185 Linköping, Sweden

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

40 Years

Sex

MALE

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2014-10-31

Primary Completion

2015-12-31

Completion

2015-12-31

Countries

• Sweden

Study Locations