Carbon monoxide poisoning (COP) may increase the risk of myocardial infarction. We conducted a study to investigate the effects of hyperbaric oxygen therapy (HBOT) on the risk. We used the Nationwide Poisoning Database in Taiwan to identify COP patients diagnosed between 1999 and 2012. We compared the risk for myocardial infarction between patients with and without HBOT by following up through 2013 and identified the independent predictors of myocardial infarction. The risk of myocardial infarction in the 7278 patients with HBOT was lower than in the 18,459 patients without HBOT, but this difference did not reach statistical significance [adjusted hazard ratio (AHR): 0.69; 95% confidence interval (CI) 0.45-1.07]. Stratified analyses showed that the reductions in the risk associated with HBOT for myocardial infarction reached statistical significance in male patients (AHR: 0.45; 95% CI 0.24-0.83) and during the first 2 weeks of follow-up (AHR: 0.22; 95% CI 0.05-0.96). In patients without HBOT, independent predictors of myocardial infarction were old age, male sex, and the underlying comorbidities of hypertension, diabetes, coronary artery disease, and congestive heart failure. In patients with HBOT, however, old age, male sex, and the underlying comorbidities of diabetes, coronary artery disease, and congestive heart failure were not independent predictors. HBOT was associated with a reduced risk of myocardial infarction in male patients and within 2 weeks following COP. These results may provide important reference for using HBOT in treating COP.
Keywords: Carbon monoxide; Hyperbaric oxygen therapy; Myocardial infarction; Poisoning.