Supplemental Oxygen in Catheterized Coronary Emergency Reperfusion (SOCCER)

• Pain difference [ Time Frame: At randomization vs at PCI balloon inflation start ] [ Designated as safety issue: No ]
  Visual analog scale
• Area at risk [ Time Frame: Day 4-6 after the acute PCI ] [ Designated as safety issue: No ]
  Assessed by cardiac magnetic resonance imaging
• Infarct size [ Time Frame: Day 4-6 after the acute PCI ] [ Designated as safety issue: No ]
  Assessed by cardiac magnetic resonance imaging
• Ejection fraction [ Time Frame: Day 4-6 after the acute PCI ] [ Designated as safety issue: No ]
  Assessed by cardiac magnetic resonance imaging
• Microvascular obstruction [ Time Frame: Day 4-6 after the acute PCI ] [ Designated as safety issue: No ]
  Assessed by cardiac magnetic resonance imaging
• Doses of opioids (substance and mg) and betablockers (substance and mg) [ Time Frame: Given before and during the PCI ] [ Designated as safety issue: No ]
• Blood oxygen saturation change [ Time Frame: From inclusion to PCI start ] [ Designated as safety issue: No ]
  Measured by pulse oximeter
• Infarct size [ Time Frame: First 24 h after inclusion ] [ Designated as safety issue: No ]
  Measured with area under TnT curve
• ST segment recovery [ Time Frame: 90 minutes after acute PCI ] [ Designated as safety issue: No ]
  As measured on ECG
• TIMI flow [ Time Frame: During acute PCI ] [ Designated as safety issue: No ]
  Measured with coronary angiography
• Use of heart failure medications (beta blockers, ACEI, ARB, diuretics, digoxin and sinus node inhibitors etc) [ Time Frame: At 6 months ] [ Designated as safety issue: No ]
• Perceived health [ Time Frame: At 6 months ] [ Designated as safety issue: No ]
  Measured with EQ-5D
• Wall motion score index on echocardiography [ Time Frame: Day 2-3 after acute PCI ] [ Designated as safety issue: No ]
  Measured on echocardiography
• Change in wall motion score index [ Time Frame: From index hospitalization to 6 months ] [ Designated as safety issue: No ]
  Measured on echocardiography

The aim of SOCCER is to evaluate the effects of treatment with supplemental O2 before and during acute balloon angioplasty (PCI) for patients with ST-elevation myocardial infarction (STEMI). One hundred STEMI patients are randomized in the ambulance to either standard O2 treatment (10 l/min) or no supplemental O2, to be given until the end of the acute PCI. Cardiac magnetic resonance imaging and echocardiography during the hospital stay is used to assess infarct size and myocardial performance. All patients are followed for 6 months. At 6 months, perceived health and NT-proBNP are recorded for all patients, and an additional echocardiography is performed. The primary endpoint is the fraction of myocardium saved with the acute PCI. The secondary endpoints include the pain difference between inclusion time and start of PCI and myocardial performance on echocardiography.

Almost all patients with ST elevation myocardial infarction (STEMI) in Sweden undergo acute balloon angioplasty (PCI) to open the occluded coronary artery, and thereby to reduce or abolish the myocardial infarction. Standard treatment in these cases is 10-15 l of supplemental oxygen to reduce the myocardial ischemia and the infarct size. It is, however, unknown whether supplemental O2 is beneficial or detrimental to patients with STEMI undergoing PCI.

This study aims to evaluate the effects of treatment with supplemental O2 in acute PCI for STEMI.

The study is a multicenter single blind parallel group randomized trial. One hundred normoxic STEMI ambulance patients accepted for primary PCI are randomized in the ambulance to either standard O2 treatment (10 l/min) or no supplemental O2, to be given until the end of the acute PCI. All patients undergo cardiac MRI at day 4-6 to determine area at risk, infarct size and myocardial salvage index. Fifty patients undergo an extended echocardiography during the hospital stay to assess infarct size and wall motion score index. All patients are followed for 6 months. At 6 months, perceived health (EQ-5D) and NT-proBNP are recorded for all patients, and an additional echocardiography is performed for the subgroup of 50 patients. The primary endpoint is myocardial salvage index. Secondary endpoints include pain difference between inclusion time and start of PCI and wall motion score index on echocardiography.

• Drug: Oxygen
  Fitting of Oxymask TM and treatment with 10 L O2/min
• Device: Room air
  Fitting of Oxymask TM

• Experimental: 10 L O2/min
  Oxygen breathing via Oxymask TM
  Intervention: Drug: Oxygen
• Sham Comparator: Room air
  Room air breathing via Oxymask TM
  Intervention: Device: Room air

• Wijesinghe M, Perrin K, Ranchord A, Simmonds M, Weatherall M, Beasley R. Routine use of oxygen in the treatment of myocardial infarction: systematic review. Heart. 2009 Mar;95(3):198-202. Epub 2008 Aug 15. Review.
• Burls A, Cabello JB, Emparanza JI, Bayliss S, Quinn T. Oxygen therapy for acute myocardial infarction: a systematic review and meta-analysis. Emerg Med J. 2011 Feb 23; [Epub ahead of print]
• Nicholson C. A systematic review of the effectiveness of oxygen in reducing acute myocardial ischaemia. J Clin Nurs. 2004 Nov;13(8):996-1007. Review.
• Beasley R, Aldington S, Weatherall M, Robinson G, McHaffie D. Oxygen therapy in myocardial infarction: an historical perspective. J R Soc Med. 2007 Mar;100(3):130-3. Review. No abstract available.
• Farquhar H, Weatherall M, Wijesinghe M, Perrin K, Ranchord A, Simmonds M, Beasley R. Systematic review of studies of the effect of hyperoxia on coronary blood flow. Am Heart J. 2009 Sep;158(3):371-7. Epub 2009 Jul 15. Review.

Inclusion Criteria:

• STEMI patient transported with ambulance to SUS Lund or Malmö or Helsingborg hospital, and accepted for acute PCI
• Symptom duration less than 6 hours
• Normal SaO2 (≥ 94 %) measured with pulse oximeter
• Informed consent

Exclusion Criteria:

• Previous AMI
• Inability to make decision to participate; dementia and the like
• For CMR: Significant claustrophobia, prostheses or other magnetic material inside the body