Hyperbaric oxygenation following thrombolysis improved myocardial contractility in acute myocardial infarction

1. HBO improved myocardial contractility on echo and was associated with a lower cardiac enzyme peak.
2. No evidence of a difference in clinical outcome.

Citation/s:
1. Dekleva M, Neskovic A, Vlahovic A, Putnikovic B, Beleslin B, Ostojic M. Adjunctive effect of hyperbaric oxygen treatment after thrombolysis on left ventricular function in patients with acute myocardial infarction. American Heart Journal 2004; 148(4):E14 [same study as Vlahovic et al 2004]
Lead author's name and fax: Dekleva M. mildek@eunet.yu

Three-part Clinical Question: In patients with an acute myocardial infarction, does adjuvant hyperbaric oxygen therapy improve cardiac function and clinical outcomes?
Search Terms: Myocardial infarction, acute coronary syndrome, thrombolysis

The Study:
Single-blinded (outcome observer) randomised controlled trial without intention-to-treat.
The Study Patients: Patients with first acute MI, less than 70 years of age, chest pain duration 30 to 360 minutes with S-T elevation and cardiac enzyme rise. Probably entered within 24 hours of infarct but not clear. Not accepted if malignant arrhythmia, severe haemodynamic instability, cardiac failure or previous cardiac surgery.
Control group (N = 37; 37 analysed): Streptokinase 1.5 mega-units followed by intravenous heparin infusion plus other drugs as required.
Experimental group (N = 37; 37 analysed): As above plus HBO at 2 ATA for 60 minutes. Given 45 minutes to 18 hrs (mean 10 hrs) after STK infusion.

The Evidence:

Event

Outcome

Time to Outcome

Control group

HBO group

Relative risk reduction

Absolute risk reduction

NNT

Cardiac Mortality

3 weeks?

0.027

0

100%

0.027

37

95% Confidence Intervals:

 

-0.03 to 0.08

NNT = 13 to INF

 NNH = 40 to INF

Angiography - collaterals

3 weeks?

0.243

0.243

5%

0.027

37

95% Confidence Intervals:

-37% to 47%

-0.20 to 0.25

NNT = 4 to INF; NNH = 5 to INF

Angiography - reperfusion

3 weeks?

0.595

0.595

0%

0.000

INF

95% Confidence Intervals:

-38% to 38%

-0.22 to 0.22

NNT = 4 to INF; NNH = 4 to INF

 

Measure

Control Group

Experimental Group

Difference

95% CI

Mean

SD

Mean

SD

Ejection fraction at 3 weeks (%)

44.05

 

50.8

 

-6.750

 

Serum creatine phosphatase (peak in units/L)

1,529

1,187

989

643

-988

-1199 to -778

Comments:
1. The methodology is difficult to follow and results are poorly reported. Time of exclusions not clear.
2. Actual time period from chest pain onset to compression is not clear, but the mean time from thrombolysis to compression was 10 hours. Outcomes might improve if the facilities were at the same site.
3. The clinical impact of the improvements reported is unclear.
4. The relevance of these findings may be altered in the setting of early interventional angiography.

Appraised by: Sean Hopson, James Hudgell and Mike Bennett, Prince of Wales Hospital, Sydney ; Friday, 24 November 2006
Email: m.bennett@unsw.edu.au
Kill or Update By: November 2007