Oxygen in acute myocardial infarction is challenged in study

The rumours that Professor Johan Herlitz mention include the Cochrane reports from 2010 and 2013, where you can deduce that no one knows whether oxygen is of any benefit as there are no randomised trials.

The current Swedish study, under the name DETO2X-AMI, which in turn stands for “DETermination of the role of OXygen in Acute Myocardial Infarction” had already started a year ago and to date has covered about 1,000 patients and more than 20 hospitals around the country. The goal is to come up to 6,600 patients and between 30-40 hospitals to ensure a sufficient sample size for the randomised trial.

The research team consists of:
Leif Svensson, Stockholm
Johan Herlitz, Gothenburg
Tomas Jernberg, Stockholm
Bertil Lindahl, Uppsala
Stefan James, Uppsala
Nils Witt, Stockholm
David Erlinge, Lund
Robin Hofmann, Stockholm

“We estimate that it will take us about 1.5 years before we have achieved this number,” Johan Herlitz predicts, a cardiologist and professor of prehospital emergency care at the Department of Health Sciences, University of Borås (pictured).

Extension of the study

Up until then, the study is planned to be extended to cover new centres in Kalmar, Umeå, Sundsvall, Skövde, Trollhättan, Kristianstad, Kalix and Kiruna among others.

The study is already being conducted in Gothenburg, Stockholm, Lund, Uppsala, Norrtälje, Enköping, Linköping, Växjö, Jönköping, Ljungby, Karlstad, Örebro, Lindesberg, Köping and Gävle.

Oxygen saturation

Only heart attack patients who meet specific criteria will be included in the study. In addition, they must be over 30 years of age and have an oxygen saturation in the blood of 90 per cent.

“In patients with acute myocardial infarction, oxygen saturation in the blood is always measured. The vast majority, 90 per cent have an oxygen saturation above 90 per cent, and it is these patients we want to look at more closely. If the patient is below 90 per cent, they will not be included in this study, as they need oxygen anyway,” says Johan Herlitz.

If the study demonstrates that oxygen does not mean any benefit - or even causes harm - to heart attack patients, it may have implications for how the care of cardiac patients is handled in the future.

“Yes, it may mean that Swedish health care stops giving oxygen to these patients entirely in this case. We will have to see what the outcome will be first,” Herlitz concludes.

Footnote: The study is being conducted with research grants from the Heart and Lung Foundation, the Swedish Foundation for Strategic Research, the Swedish Research Council and Swedeheart.  

Copy: Eva-Lotta Andersson
Photo: Ulf Nilsson/MIM-Bild