Hyperbaric oxygen and thrombolysis in myocardial infarction: the "HOT MI" pilot study

Hyperbaric oxygen treatment (HBO) in combination with thrombolysis has been demonstrated to salvage myocardium in acute myocardial infarction in the animal model. Therefore a randomized pilot trial was undertaken to assess the safety and feasibility of this treatment in human beings. Patients with an acute myocardial infarction (AMI) who received recombinant tissue plasminogen activator (rTPA) were randomized to treatment with HBO combined with rTPA or rTPA alone. Sixty-six patients were included for analysis. Forty-three patients had inferior AMIs (difference not significant) and the remainder had anterior AMIs. The mean creatine phosphokinase level at 12 and 24 hours was reduced in the patients given HBO by approximately 35% (p = 0.03). Time to pain relief and ST segment resolution was shorter in the group given HBO. There were two deaths in the control group and none in those treated with HBO. The ejection fraction on discharge was 52.4% in the group given HBO compared with 47.3% in the control group (difference not significant). Adjunctive treatment with HBO appears to be a feasible and safe treatment for AMI and may result in an attenuated rise in creatine phosphokinase levels and more rapid resolution of pain and ST segment changes.