Impact of COVID-19 Pandemic Healthcare Restrictions on Utilization and Diagnostic Yield of Outpatient Transthoracic Echocardiograms

Background: In 2014, appropriate use criteria (AUC) were introduced for initial outpatient pediatric transthoracic echocardiograms (TTEs). These criteria classified common indications for echocardiograms as appropriate (A), may be appropriate (M), and rarely appropriate (R). In 2020, a subsequent AUC guideline provided further direction regarding utilization of TTE in longitudinal follow-up of congenital heart disease (CHD). In response to the COVID-19 pandemic, a Kentucky executive order prohibited elective medical procedures from 3/18/2020-4/27/2020. Simultaneously, the American Society of Echocardiography recommended limiting rarely appropriate studies. Our primary objective was to determine if the cessation of elective medical procedures in Kentucky during the COVID-19 pandemic resulted in a decrease in the proportion of rarely appropriate outpatient TTEs interpreted at the open echocardiography lab at Norton Children’s Hospital. Differences in appropriateness of echocardiogram orders by provider type were evaluated, and diagnostic yield of outpatient pediatric TTEs prior to and during this time period were compared.

Methods: A retrospective chart review was conducted comparing proportions of rarely appropriate outpatient pediatric TTEs performed pre-COVID (3/21/2019-4/28/2019) and during COVID (3/19/2020-4/27/2020). All outpatient TTEs interpreted at our institution performed on subjects <=18yrs of age in Kentucky facilities during the relevant time periods were eligible for inclusion. Studies performed outside of Kentucky were excluded. TTE indication was determined by chart review and echocardiogram reports. Appropriateness of indication was evaluated using pediatric AUC guidelines for initial outpatient TTE or CHD follow-up. Variables collected included study date, indication, findings, referring provider type, and prior known cardiac diagnosis when relevant. The statistical analyses used for the data consisted of descriptive, bivariate, and logistic regression modeling.

Results: Of 767 TTEs reviewed, 486 met inclusion criteria: 364 pre-COVID vs. 122 during COVID. TTE indication was classifiable in 354 (72.8%) of studies. Of TTEs pre-COVID, 100 (37.7%) were rarely appropriate vs. 18 (20.2%) during COVID (p=0.002, Table 1.) Pediatric cardiologists tended to order fewer rarely appropriate TTEs than pediatricians pre-COVID (35.9% vs. 46.4%), although this difference was not statistically significant. Cardiologists ordered the majority of outpatient TTEs during COVID (77/89 TTEs, 86.5%), limiting the ability to compare TTE indications by provider type. There was no significant difference in diagnostic yield of initial outpatient TTEs with 32 (8.9%) abnormal studies pre-COVID vs. 12 (10.9 %) during COVID (p=0.574, Figure 1).

Conclusion: The executive order prohibiting elective procedures during the COVID-19 pandemic in Kentucky resulted in a decrease in the proportion of rarely appropriate outpatient pediatric TTEs. There was no significant difference in diagnostic yield of initial outpatient TTEs between time periods, suggesting that clinically significant echocardiogram findings were still detected despite more prudent utilization of echocardiography during this time.