Increased risk of acute myocardial infarction after the Great East Japan Earthquake

Strong psychosocial stress is considered to be a precipitating factor in acute coronary events. To assess the hypothesis that the incidence of acute myocardial infarction (AMI) and its severity was remarkably heightened after the great earthquake, we retrospectively analyzed the clinical data of patients with AMI admitted to our hospital during a 3-week period between March 11 and March 31, 2011 (disaster group) as compared with AMI patients during the corresponding time period of 2010 (non-disaster group). The number of patients with AMI in the disaster group increased by about threefold (22 in the disaster group vs. seven in the non-disaster group). Compared with the previous years 2010 or 2009, the odds ratios [OR] for AMI during a 3-week period in 2011 were 4.40 (95 % confidence interval [CI]: 1.05–18.35), 5.66 (95 % CI: 1.42–22.59), respectively. Although the number of patients who underwent coronary revascularization was higher in the disaster group than in the non-disaster group (68.2 vs. 42.9 %, p = 0.0397), peak serum creatine kinase (CK)-MB level was significantly higher in the disaster group than in the non-disaster group (208.0 ± 159.0 vs. 149.3 ± 102.7 IU/l, p = 0.0431). In the disaster group, four patients died of cardiac causes, whereas no patient died in the non-disaster group (in-hospital mortality rate in the disaster vs. non-disaster group: 18.2 vs. 0 %, p = 0.0281). These results suggest that patients with AMI after the earthquake might be subject to strong psychosocial stress, and that psychological stress brought on by such disaster could trigger cardiac events and cardiac death.