924-118 The January 17,1994 Los Angeles Earthquake as a Trigger for Acute Myocardial Infarction

Abstract

The January 17, 1994 Los Angeles earthquake (EQ) provided a unique opportunity to examine the effect of extensive environmental disaster associated with tremendous emotional stress on the incidenCe of acute cardiac events. We surveyed 75 coronary care units (CCUs) in Southern California comparing the number of admissions for myocardial infarction (MI), unstable angina (UA), total CCU admissions and related in-hospital mortality in the week before (Jan 10–16) and after (Jan 17–23) the EQ. Five CCUs were excluded because of insufficient data. The relative risk for MI following the EQ was assessed in a subgroup of 29 CCUs that were able to provide data on the equivalent period in 1993. Total number of pts (average number ± SD per CCU): cases Week Before Week After p Value MI 147 (2.1 ± 2.7) 195 (2.9 ± 3.1) 0.01 UA 255 (3.6 ± 5.2) 273 (3.9 ± 5.2) 0.39 Total CCU pts 1096 (15.7 ± 13.2) 1174(16.8 ± 13.2) 0.18 The % of CCU admissions for Ml increased in the week following the EQ [195 of 1174 (16.6%) vs. 147 of 1096 (13.4%); P = 0.04]. The % of CCUs reporting increased number of MIs was higher in hospitals located within 15 miles of the EQ epicenter vs. hospitals located > 15 miles [11 of 14 (79%) vs. 23 of 56(41%); p = 002]. In-hospital mortality (%) was similar for Ml and UA pts in the week before and after the EQ (Ml: 7% vs. 6%; UA: 1% vs. 0%, respectively). In comparison to 1993 (subgroup of 29 CCUs), there was a significant increase in the risk of developing MI in the week following the EQ vs. the week before (1994: 70 vs. 41 pts; 1993: 49 vs. 68 pts, respectively; odds ratio 2.4, 95% confidence interval 1.4 – 4.0). 1) Our data indicate a significant increase in the incidence of Ml but not UA or in hospital mortality in the week following the EQ. 2) Our observation supports the concept that a stressful event can trigger acute MI.