COVID-19 PANDEMIC INDUCED DISRUPTIONS IN TROPONIN AND LOW-DENSITY LIPOPROTEIN CHOLESTEROL LABORATORY TEST VOLUMES ACROSS ALBERTA

BACKGROUND Atherosclerotic cardiovascular disease (ASCVD) is a leading cause of morbidity and mortality in Canada and worldwide. Laboratory tests, including troponin and low-density lipoprotein cholesterol (LDL-C), are important biomarkers of ASCVD risk. The objective of this study was to investigate patterns of testing for troponin and LDL-C test volumes among Alberta residents during the coronavirus disease 2019 (COVID-19) pandemic. METHODS AND RESULTS A repeated cross-sectional study design captured population-level laboratory test volumes between March 15, 2019 and December 14, 2020. Three-month cross-sections were derived to report laboratory test volumes by different COVID-19 restriction periods during 2020-2021 and using 2019-2020 as a preceding control period. Percent change for troponin and LDL-C test volumes were calculated for both control and COVID-19 periods among adult (≥18 years of age) Alberta residents, and stratified by age (18-49, 50-65, 66-79, and ≥80 years), sex, and geographic zones (urban, rural). This preliminary data is part of an ongoing study for which further troponin and LDL-C test volumes will be available up until March 14, 2021 (representing one year of data throughout the COVID-19 pandemic). Among the Alberta population, 292,836 troponin and 794,789 LDL-C tests were captured between March 15, 2020 and December 14, 2020 (Figure 1). Testing patterns during the COVID-19 restriction period showed marked reduction in test volumes from the previous year. The initial cross-section of the COVID-19 period (March-June 2020) was characterized by the largest overall reduction with troponin test volumes decreasing 18% and LDL-C test volumes decreasing 63%, compared to the year prior. As restrictions eased in the summer months of 2020, testing volumes rebounded to near pre-pandemic volumes for both tests. However, in the fall of 2020, troponin tests decreased again (-15%). Within these drops in utilization, slightly larger relative declines were observed for troponin test volumes in women (-20%) and patients ≥80 years-old (-25%) and for LDL-C test volumes among urban residents (-64%), women (-67%) and patients aged 18-49 (-66%) and 50-65 (-65%) years (Table 1). CONCLUSION This study describes declines in troponin and LDL-C test volumes in the initial and second COVID-19 lockdown periods. Women had overall smaller total troponin and LDL-C test volumes and larger relative declines during the pandemic compared to men. The decrease in these ASCVD-related laboratory test volumes during the pandemic may have been accompanied by other important changes in indicators of healthcare utilization and associated clinical outcomes. Ongoing analyses will further explore the impact of the pandemic.