The Effects of the COVID-19 Pandemic on Cardiac Surgery Volumes and Outcomes in New Zealand.

Abstract

New Zealand adopted an "elimination strategy" in response to the 2020 COVID pandemic with strict early border controls and early national lockdowns. The international experience of cardiac surgery provision during the COVID pandemic was of reduced case numbers, difficulties with the provision of elective surgery and in some cases increased morbidity associated with waiting for surgery and from developemnt of the infection in post operative patients. We aim to review the effects the COVID-19 pandemic has had on adult cardiac surgery volumes and outcomes in the Wellington region. Utilising local data submitted to the New Zealand National cardiac surgical database, we analysed all cardiac operations completed at a tertiary cardiothoracic centre between January 1st 2019 till December 31st 2020. The COVID-19 lockdown period (March-April 2020) was compared with its' 2019 counterpart as well as the sequential months to analyse for any 'rebound' effect. Number of surgeries, proportion of elective cases, and surgery type were assessed. The lockdown period of March-April/2020 showed a higher number of cardiac surgery cases per month compared to a the same period in 2019 (48.5 vs 39.0 cases/month, P=0.74). A surge in acute cases was noted in September-December 2020 with 57 acute operations completed, compared to 23 for the corresponding time period in 2019. The New Zealand response to the COVID pandemic resulted in low relative rates of community transmission and only a small number of patients admitted to hospital. We did not see a reduction in routine cardiac operations or changes in clincial outcome over this period. Despite the lockdown period, due to low numbers of community and COVID cases in our ICU and hospital we were able to maintain a full operating capacity throughout. We did observe an increase in acute cases following the lockdown likely due to the reduced access to routine cardiology clinics and deferrable diagnostic services.