CA = Cardiac Arrest (aka "heart attacks")

ACS = Acute Coronary Symptoms (e.g. chest pains, etc.)

https://www.nature.com/articles/s41598-022-10928-z

The main finding of this study concerns with increases of over 25% in both the number of CA calls and ACS calls of people in the 16–39 age group during the COVID-19 vaccination rollout in Israel (January–May, 2021), compared with the same period of time in prior years (2019 and 2020), as shown in Table 1. Moreover, there is a robust and statistically significant association between the weekly CA and ACS call counts, and the rates of 1st and 2nd vaccine doses administered to this age group. At the same time there is no observed statistically significant association between COVID-19 infection rates and the CA and ACS call counts. This result is aligned with previous findings which show increases in overall CA incidence were not always associated with higher COVID-19 infections rates at a population level35,49,50, as well as the stability of hospitalization rates related to myocardial infarction throughout the initial COVID-19 wave compared to pre-pandemic baselines in Israel51. These results also are mirrored by a report of increased emergency department visits with cardiovascular complaints during the vaccination rollout in Germany52 as well as increased EMS calls for cardiac incidents in Scotland53.