Nationwide analysis of the relationship between low ambient temperature and acute aortic dissection-related hospitalizations

Abstract Aims Acute aortic dissection (AAD) is a life-threatening cardiovascular emergency. Therefore, identifying modifiable risk factors for AAD is of great public health significance. An association between ambient temperature (AT) and AAD has been reported; however, not all findings have been elucidated. This study examined the association between AAD-related hospitalization and AT using data from the Japanese Registry of All Cardiac and Vascular Diseases Diagnostic Procedure Combination (JROAD-DPC), which is a nationwide claims-based database. Methods and results This nationwide time-stratified case-crossover study evaluated data of hospitalized patients with AAD from 1119 certified hospitals between 2012 and 2020 using the JROAD-DPC database. Conditional logistic regression and distributed lag non-linear models were used to investigate the association between average daily temperature and AAD-related hospitalization. Among the 96 812 cases analysed, the exposure–response curve between AT and AAD-related hospitalization showed an increase in the odds ratio for lower temperatures, with a peak at time −10°C (odds ratio: 2.28, 95% confidence interval: 1.92–2.71, compared with that at 20°C). The effects of temperature on lag days 0 and 1 were also significant. Stratified analyses showed a greater association between AT and AAD-related hospitalization for the following variables: older age (≥75 years), female sex (44.4%, the mean age ± SD was 76 ± 12 years), low body mass index (<22), winter season, and warmer regions. Conclusion Low AT is associated with an increased risk of AAD-related hospitalization. Several susceptible groups are affected by cold temperatures and have a higher risk of hospitalization.