For decades, oxygen has been given to heart attack patients as standard. However, this is not strictly necessary – and may even end up being detrimental to patients.
Back in 2014, a study was published that cast doubt on the routine provision of oxygen to heart attack patients. The Australian research team led by Dr. Dion Stub had compared the effect of this measure, which had been practised for decades, with that shown by patients breathing in the ambient air. The result was worrying: the supply of oxygen had more negative than positive effects. Within six months after the infarction, cardiovascular complaints occurred more frequently than in the ambient air patient group.
The study entitled “Air Versus Oxygen in Myocardial Infarction” did not make much of a splash because the number of subjects was very manageable at 638. In order to obtain reliable results, a significantly higher number of participants is required. This was achieved – with more than ten times as many patients – in a Swedish study that was recently published in the “New England Journal of Medicine”. Its results go in the same direction as those of the 2014 study.
Oxygen should only be administered when indicated.
About half of the 6,629 heart attack patients received oxygen for an average of about eleven and a half hours via a breathing mask, while the comparison group only breathed ambient air. In terms of mortality, the different treatment did not lead to any significant differences: “Within one year, there were about the same number of deaths in both groups of test persons: 5.0 percent with oxygen supply, 5.1 percent without,” explains cardiologist Dr. Rainer Ruf from the Outpatient Centre in Berlin-Friedrichshain. “The difference is not statistically significant, unlike the different values for repeat inpatient treatments in the same period: while 3.8 percent of the patients with oxygen administration were admitted to hospital again, it was only 3.3 percent in the comparison group,” the cardiologist continues.
Based on these results, the Swedish researchers conclude that the blanket supply of oxygen after a heart attack does more harm than good. The gas should only be administered if there is a specific indication. The main indications are acute heart failure and hypoxia (oxygen deficiency).