Background:
The SARS-CoV2 pandemic has put practical algorithms of medical treatments to the test and confronted the clinics worldwide with various challenges. There is a unique constellation in the state of Thuringia observing the course of incidences during both lock-downs in 2020. While looking on equal political measures to limit social contacts in both time frames, we experienced a first lock-down with very low COVID19 incidences and sufficient medical resources, and a second (and 3^rd) lock-down with very high incidences and vanishing resources. Care for acute coronary syndrome (ACS) under pandemic conditions is challenging, since acute care is time sensitive and symptoms of ACS and COVID19-infection are overlapping.

Objective:
(1) To investigate the impact of political lockdown measure on acute care for ACS  during SARS-CoV2-pandemic in a high, volume PCI center and in the state of  Thuringia, and (2) to compare the impact of the 1^st wave with locally extremely low COVID19-incidences vs. 2^nd and 3^rd waves with high COVID19-incidences.

Methods:
This is an observational all comers cohort study at the University Heart Center, Jena, Germany.  The overviewed time span of our observation reaches from January of 2020 to April of 2021 (lock-down no.1 in 03/04 2020 and lock-down no.2/3 in 09/10 2020 – 03/04 2021included). Additional time frames before and between lockdowns were used as comparators. Various administrative, procedural, therapeutic and clinical parameters were anonymously recorded to analyze the patient’s individual clinical characteristics, their performance and the pre- and intrahospital work flow.

Results:
Overall, 975 Patients presented with ACS during the months between 03 – 05/06 2019 (pre-pandemic comparator group) and 01/02 2020 – 03/04 2021. Beginning with months of increasing COVID19-incidences and subsequent lockdown during the 2^nd/3^rd wave in fall/winter 2020, numbers of STEMI cases considerably reduced. The progress of diminution seems to accentuate itself into December of 2020, the month of highest  COVID19 infection rates. Conversely, patient performance (onset-to-first medical contact time) worsened during these times (Fig.1).  Pre- and intrahospital workflows (e.g. prehospital time, contact-to-wire and door-to-wire time) remained stable with a tendency to even faster care during lockdown months (Fig. 2). Also, inadequate therapy delays of STEMI patients after first-medical contact occurred less frequently during lockdown (Fig. 3). A potential effect of low ACS patient volume during this time has to be discussed. Alterations are found in the frequency of non-invasive-diagnostics in ACS patients (Fig. 4). CT-scans for evaluation of the thorax to exclude COVID19 pneumonia were ordered more often with the beginning of the COVID19-pandemic, and since then remained relatively high and stable (average of ~ 17% pre-pandemic vs. ~ 26 % pandemic; Fig. 4).

Conclusion:
The absolute numbers of ACS patients sank during both political lockdown measures. Considering Thuringia’s unique setting being determined by equal political measures while having low COVID19 infections in the first, then high infections in the second lock-down, one can identify political actions and a doubtful population as the reason for alteration in ACS cases. However, quality of care of ACS patients, that seeked medical attention, was not impaired.