Impact of the COVID-19 pandemic on incidence and mortality of emergency cardiovascular diseases in Tokyo.

Background: The impact of the coronavirus disease 2019 (COVID-19) pandemic on the incidence and in-hospital mortality of emergency cardiovascular disease (CVD) has not been clarified in Japan.

Methods: We compared the number of admissions and in-hospital mortality for emergency CVD during the pandemic (from January to December 2020) with those of pre-pandemic periods (from January 2018 to December 2019), using quarterly data from the Tokyo Cardiovascular Care Unit Network. The incidence rate in 2020 is compared with the average incidence rate observed in the same quarter of 2018 and 2019 and is presented as an incidence rate ratio (IRR) with 95 % confidence interval (CI).

Results: The number of admissions for acute myocardial infarction during the pandemic was significantly lower than before the pandemic, with an IRR of 0.93 (95 % CI; 0.88-0.98). Similarly, the IRR for unstable angina was 0.78 (95 % CI; 0.72-0.83), for acute heart failure was 0.84 (95 % CI; 0.76-0.91), for acute aortic dissection was 0.88 (95 % CI; 0.78-0.98), and for ruptured aortic aneurysm was 0.75 (95 % CI; 0.62-0.88). In quarterly comparisons, the numbers of acute aortic diseases and emergency arrhythmia significantly decreased from July to September 2020, while those of other emergency CVDs significantly declined in the 2020 April-June period, which includes the first wave period in Japan. In-hospital mortality of emergency CVDs was unchanged from the pre-pandemic period, except for acute aortic dissection, which increased in odds ratio of 1.31 (95 % CI 1.10-1.57).

Conclusions: The COVID-19 pandemic significantly reduced the number of admissions for all emergency CVDs in all or part of the year. In-hospital mortality was unchanged from the pre-pandemic period, except for acute aortic dissection, which increased.