Unusual Incidence of Acute Type A Aortic Dissection during COVID-19.

Seasonal variations have been identified in the incidence of Stanford acute type A aortic dissection (ATAAD), and these have been only further impacted by the recent COVID-19 pandemic. We sought to examine the incidence and presentation of ATAAD during the initial height of the COVID-19 pandemic during the year 2020 and compare this with our pre-pandemic experience. A retrospective review was undertaken of all consecutive patients who had ATAAD repair between January 2014 and December 2020. The incidence and pattern of presentation during 2020 was compared with that of the prior 6 years. A total of 339 patients underwent ATAAD during the study period, 301 (88.8%) from 2014 to 2019 (pre-COVID-19) and 38 (11.2%) during 2020 (coincident with COVID-19). We found a marked decrease in the incidence of ATAAD during COVID-19 as compared to the aggregate of our prior experience. During the height of the COVID-19 pandemic, we witnessed significantly fewer patients presenting with ATAAD, presumably due to a combination of "lockdown" restrictions, perhaps coupled with reduced influenza activity in the population. This was followed by an unusual rebound in the incidence of ATAAD, a phenomenon not previously noted.