Earthquake-related cardiovascular mortality worldwide. Are young women the most susceptible population?

Introduction: Earthquakes are important emotional stressors capable to trigger acute cardiovascular events, like acute myocardial infarction (AMI). However, earthquake-induced stress may affect sexes and age-groups differently. Using worldwide data, we assessed if earthquake-related AMI mortality diverges from the expected, according to age-group and sex.

Methods: A retrospective review of earthquake-related AMI mortality was conducted. Sex and age of the victims were retrieved and distributed by age-groups (<70, ≥70 years old) and by World Health Organization (WHO) region. Search was based on the US Geological Survey, OCHA Reliefweb and Earthquake Report datasets. Additional information obtained from newspapers was used to complete demographic data of the victims.  To compare observed with expected sex-ratios, death counts of coronary heart disease (CHD, no data on AMI mortality) by sex, age-group and WHO region were collected. Chi-square test was used for comparisons and odds ratios (OR) and 95% confidence intervals (CI95%) calculated.

Results: We got demographic information about 237 earthquake-related AMI deaths, covering the period 1977-2013: 58 males and 75 females under 70 years; 48 and 56 aged ≥70 years. Worldwide, the expected female proportion of deaths from CHD under 70 years old was 33.4%, whereas for only earthquake-related AMI mortality was 56.4% [47.9-64.5]. Sex ratio (W/M) for earthquakes was 2.58 [1.81-3.70] times higher than for all-cause CHD mortality. Significant associations were also found for Europe (2.12, 1.16-3.87), South-east Asia (3.45, 1.04-13.12), Western Pacific (3.80, 1.35-12.20) and America (2.77, 1.49-5.24); but not for Eastern Mediterranean and Africa, where cases or demographic data were not sufficient. No sex unbalances were found for older adults. 

Conclusions: Younger women presented a 2.6-fold increase of the risk of dying from AMI in an earthquake, when compared with other CHD causes. Community-based interventions aiming at instructing high-risk groups to manage earthquake-induced stress might postpone the occurrence of acute cardiovascular events.