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. |
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