ESC Congress 2017 In Review – Focus on CAD&ACS - 9

ESC Congress 2017

Late-Breaking Clinical Trials

In Review

CAD & ACS

Supplemental Oxygen No Better
Than Ambient Air: Results From
the DET02X-AMI Study
Written by Brian Hoyle
Figure 1. Primary Endpoint at 1 Year
6
5
4

Mortality (%)

The findings of a registry-based randomised clinical trial
(RCT) involving 6,629 patients have shown that routine
oxygen therapy for nonhypoxaemic patients with suspected acute myocardial infarction (AMI) does not reduce
all-cause mortality at 1 year compared with ambient air.
The results of the DETO2X-AMI study [Hofmann R et
al. N Engl J Med. 2017] were presented by Robin
Hofmann, MD, Karolinska Institutet, Stockholm, Sweden.
Oxygen therapy has been used for over a century for
AMI patients, and it is recommended in clinical guidelines. The rationale of the approach is the belief that the
delivery of more oxygen to the ischaemic myocardium
reduces the infarct size and subsequent complications.
On the other hand, above-normal oxygen levels can
produce or cause coronary constriction. Data supporting the benefit of routine oxygen therapy in terms of
patient survival are lacking. A recent systematic literature review confirmed conflicting data on the benefits
of oxygen therapy in acute coronary syndrome patients
[Shuvy M et al. Eur Heart J. 2013].
The national SWEDEHEART cardiac registry collects
data from 69 Swedish hospitals that provide comprehensive coronary care, and manage over 90% of the
annual AMIs in Sweden. Inclusion criteria were classical symptoms of AMI within the previous 6 hours, age
≥ 30 years, oxygen saturation ≥ 90%, and suspected
myocardial damage evident by either characteristic
electrocardiogram changes or elevated troponin level.
Patients already receiving routine oxygen therapy were
excluded, as were those who experienced a cardiac
arrest before enrollment.
The 6,629 patients with suspected MI were randomised to receive supplemental oxygen delivered at a
rate of 6 L/minute for 6-12 hours (median duration 11.6
hours) using an open face mask (n = 3,311) or normal
breathing of ambient air (n = 3,318). The primary endpoint in the intention-to-treat population was all-cause
death within 1 year post randomisation.
At baseline, the 2 groups were similar demographically and clinically. No patients were lost to follow-up for
the primary endpoint.
The primary endpoint of 1-year mortality was similar
among the 2 groups (5.0% in the oxygen group vs 5.1%
in the ambient air group; HR, 0.97; 95% CI, 0.79 to 1.21;
P = .80; Figure 1).

Ambient air
Oxygen treatment

Ambient air 5.1%
Oxygen treatment 5.0%

122

152

182

213

243

274

304

335 365

Days since Randomisation
No. at risk
Oxygen treatment 3311 3238 3227 3218 3210 3201 3189 3182 3175 3170 3165 3159 3145
Ambient air
3318 3251 3235 3224 3215 3202 3190 3177 3169 3166 3162 3160 3150

From The New England Journal of Medicine, Loscalzo J et al, Oxygen Therapy
Beneficial in Acute Myocardial Infarction? Simple Question, Complicated
Mechanism, Simple Answer, EPub 28 August 2017. Copyright © 2017 Massachusetts
Medical Society. Reprinted with permission from Massachusetts Medical Society.

Cardiac troponin T levels were nearly identical in the
2 groups (P = .97). Finally, there was no significant benefit to routine oxygen treatment across subgroups of AMI
diagnosis, infarction type, sex, advanced age, smoking,
diabetes, chronic kidney disease, anaemia, and prior history of MI or percutaneous coronary intervention.
In conclusion, routine use of oxygen in patients with
suspected AMI without hypoxaemia did not reduce
1-year all-cause mortality.

Results From the COMPASS Study
Written by Maria Vinall

Cardiovascular disease (CVD) affects 300 million persons worldwide, about 4% of the worlds' population.
Aspirin is the most widely used preventive treatment
but it reduces CV events by only 19% long-term. The
ATLAS TIMI-51 trial [Mega JL et al. N Engl J Med. 2012]
established the efficacy of low doses of rivaroxaban, a
selective direct factor Xa inhibitor, in patients with acute
coronary syndrome. John W. Eikelboom, MD, McMaster
University, Hamilton, Ontario, Canada, presented the primary results of the COMPASS trial [Eikelboom JW et al.
N Engl J Med. 2017], which aimed to extend the results
Official Peer-Reviewed Highlights From ESC Congress 2017

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