Vlahovic

Hyperbaric oxygenation did not affect measures of left ventricular stiffness, but was associated with lower enzyme levels and lower requirement for beta-blockers and anti-arrhythmics in patients with acute myocardial infarction

Clinical Bottom line:

1. No significant effect of HBOT on left ventricular stiffness assessed by echocardiography.
2. HBOT may have resulted in smaller infarct size.

 Citation/s:1. Vlahovic A, Neskovic AN, Dekleva M, Putnikovic B, Popovic ZB, Otasevic P, Ostojic M. Hyperbaric oxygen treatment does not affect left ventricular chamber stiffness after myocardial infarction treated with thrombolysis. American Heart Journal 2004; 148:J1-J7.


Lead author's name and email: neskovic@hotmail.com

Three-part Clinical Question:For patients with an acute myocardial infarction, does the adjunctive administration of hyperbaric oxygen following thrombolysis, compared to thrombolysis alone, result in any improvement in left ventricular stiffness or infarct size?

Search Terms:myocardial infarction, cardiac enzymes, echocardiography

The Study:Non-blinded randomised controlled trial with intention-to-treat.

The Study Patients:Proven acute MI in patients under 70 years with ECG changes and enzyme rise, and without heart failure or malignant arrhythmias.

Control group(N = 37; 37 analysed): Streptokinase 1.5m IU at mean time of 2.4 hours.

Experimental group(N = 37; 37 analysed): Streptokinase as above (mean time to treatment 3.0 hours), followed by 100% oxygen at 2 ATA for 60 minutes (mean time to treatment 13 hours).

The Evidence:

Outcome

Time to Outcome

Control group

HBOT group

Relative risk reduction

Absolute risk reduction

Number needed to treat

Needed intravenous beta-blockers

not known

0.16

0.03

83%

0.14

7

95% CI:

3% to 100%

0.01 to 0.27

4 to 189

Needed antiarrhythmics

not known

0.30

0.11

64%

0.19

5

95% CI:

4% to 100%

0.01 to 0.37

3 to 91

 

Measure

Control Group

Hyperbaric Group

Difference

95% CI

Mean

SD

Mean

SD

Peak creatine phosphokinase level (IU)

1529

1187

989

643

540

98.2 to 981.9

Wall motion score index

1.52

0.7

1.38

0.5

0.14

-0.14 to 0.42

Deceleration time (early filling velocity)

Not given

Not given

 

P = 0.87

 

Comments:

1. Generally this group of patients had small infarcts with a mild degree of systolic and diastolic dysfunction. The effect of HBOT in a higher risk group is not clear from this study.

2. There is a mean time from pain onset to HBOT of 13 hours, and this may mean many patients missed an early time window when HBOT may have been more efficaceous.

3. Only an indirect measure of infarct size was measured in this study - CK levels.

Appraised by:Mike Bennett, POWH; m.bennett@unsw.edu.au; Friday, 6 July 2007

Kill or Update By:June 2024

 

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