Background: Admission numbers of patients with an acute cardiac event significantly declined during the initial phase of the COVID-19 pandemic. Data on the relation between non-emergency and emergency admission rates during the lockdown and post-lockdown period are sparse.

Aim: The aim of this study was to determine the time-dependent course of non-emergency and emergency admissions of cardiac patients treated at a high-volume cardiac center before, during, and after COVID-19-related lockdown.

Methods: This monocentric retrospective study included consecutive patients suffering from cardiac diseases admitted to our tertiary heart center between January 1st and June 30th 2020. The observation period of 6 months was analyzed in total and divided into three defined time periods: the pre-lockdown (January 1st - March 19th), the lockdown (March 20th to April 19th) and the post-lockdown (April 20th to June 30th) period. These were compared to the reference periods in 2019 and 2022 using daily admission rates and incidence rate ratios (IRR).

Results: Over the observation period from January 1st to June 30th cardiac admissions (including non-emergency and emergency) were comparable between 2019, 2020 and 2022 (n=2,889, n=2,952, n=2,956; p=0.845). However, when compared to the reference period 2019, non-emergency admissions decreased in 2020 (1,364 vs.1,663; p=0.02), while emergency admissions significantly increased (1,588 vs. 1,226; p<0.001). Further analysis of the lockdown period revealed that the non-emergency admissions dropped by 82% (IRR 0.18; 95%-CI 0.14 – 0.24; p<0.001) and 42% fewer invasive cardiac interventions were performed (p<0.001) compared to the control period 2019. The post-lockdown period showed a 52% increase of emergency admissions compared to the reference period in 2019 (IRR 1.47 95%-CI 1.31 - 1.65; p<0.001). Additionally, we observed a numerical increase of invasive cardiac procedures by 15% (p=0.149).

Conclusion: We demonstrate a drastic surge of emergency cardiac admissions post COVID-19 related lockdown suggesting that patients who did not keep their non-emergency appointment had to be admitted as an emergency at a later time. Medical professionals should carefully balance the benefits and risks of postponing non-emergency interventions, even in the current and future pandemics.