Abstract 12850: Increased Incidence of Acute Myocardial Infarction after the Great East Japan Earthquake

Abstract

Background: On March 11, 2011, we experienced the Great East Japan Earthquake in the Tohoku area, Japan. It has been previously reported that the incidence of acute myocardial infarction (AMI) was increased after earthquakes; however, there is no report about the incidence and the clinical characteristics of AMI patients after an earthquake. Thus, we conducted a single-center cohort study to examine the clinical characteristics of AMI patients before and after the Earthquake.

Methods: We enrolled all patients with AMI who admitted to the Iwate Prefectural Central Hospital during the 1-month period after the Earthquake from March 11 to April 10 in 2011 (disaster group, n=23) and those in the corresponding period of 2009 and 2010 (non-disaster group, n=18). We examined the incidence and clinical characteristics of AMI patients in the 2 groups.

Results: The number of patients with AMI in the disaster group was significantly increased by about 2-fold (23 patients/month in 2011 vs. 7 patients/month in 2010 and 11 patients/month in 2009, both P<0.01). The disaster group had a significantly greater prevalence of hypertension than in the non-disaster group (87.0% vs. 55.6%, P<0.05). The disaster group had significantly lower plasma levels of total cholesterol (147±6 vs. 188±11 mg/dl, P<0.05), low-density lipoprotein cholesterol (97±7 vs. 125±11 mg/dl, P<0.05) and less prevalence of history of smoking (17.4% vs. 50.0%, P<0.05). No significant difference was noted between the 2 groups in terms of age, sex, diabetes mellitus, familial history of AMI and medications. In-hospital mortality rate of the disaster group was not significantly different from that of the non-disaster group (17.4% vs. 11.1%, P=0.57). The incidence of congestive heart failure after AMI during the initial hospitalization was also not significantly different compared with the non-disaster group (34.8% vs. 16.7%, P=0.19).

Conclusions: These results indicate that the incidence of AMI was significantly increased after the Great East Japan Earthquake compared with the same period in the past 2 years and that the occurrence of AMI was accelerated in patients with a less number of risk factors except hypertension.