Role of climatic factors in the incidence of Takotsubo syndrome: A nationwide study from 2012 to 2016

Aims: This study aimed to investigate the influence of climatic factors on the onset of Takotsubo syndrome (TTS). Methods and results: We performed a retrospective nationwide study among patients registered in the Japanese Registry of All Cardiac and Vascular Diseases and Diagnosis Procedure Combination (JROAD–DPC) discharge database, between 2012 and 2016. Before the analysis, a multicentre validation study was conducted for assessing the accuracy of the JROAD–DPC classification for TTS. First, we investigated the seasonal variation of incidences of TTS. Second, we analysed the associations between the incidence of TTS and climatic factors using the hierarchical Poisson regression modelling, and we also investigated the associations between typhoon landfalls and hospitalization for TTS, using the fixed-effects conditional Poisson regression model. The sensitivity and specificity for diagnosis were 83% and 100%, respectively. Then we analysed 5643 patients with TTS. The mean patient age was 74 (standard deviation ± 11) years; 79% were female. TTS was diagnosed significantly more frequently in the summer and early autumn. The incidence of TTS was related to higher temperatures; adjusted incidence rate ratios were 1.46 [95% confidence interval (CI): 1.33–1.60, P < 0.01] and 1.47 (95% CI: 1.34–1.62, P < 0.01) for temperatures of 20–25°C and >25°C, respectively. The incidence rate ratio for the first 2 days after a typhoon landfall was 1.85 (95% CI: 1.07–3.19; P = 0.03). Conclusions: This study demonstrates distinct patterns of seasonal variation in the incidence of TTS, as well as a significant association between its onset and climatic factors, including typhoon landfalls.