Abstract 16698: Cardiopulmonary Exercise Testing With an In-Line Filter During the COVID-19 Pandemic

Abstract

Introduction: During maximum incremental exercise expiratory flow rates increase > 10-fold and minute ventilation can exceed 100L/min, raising concern for possible spread of COVID-19 in asymptomatic patients undergoing exercise testing. Moreover, use of surgical or N95 masks that limit airflow are recognized to limit the ability to perform maximum exercise. Hypothesis: Use of an in-line filter during cardiopulmonary exercise testing is feasible and will not adversely impact measurements of exercise capacity. Methods: We conducted a proof-of-principle study in which a commercially available electrostat filter (Figure 1A), which has >99.9% viral efficiency without affecting spirometry measurements during pulmonary function testing, was placed in-line, upstream of the flow meter and gas analyzer sample line for use during cardiopulmonary exercise testing. A single healthy subject completed incremental exercise with a 3 min period of unloaded exercise followed by 4-min stages of exercise at 50, 100, 150, and 200W with and without the filter in place on the same day. Mechanical dead space was 53 ml with the filter and 45 ml without. Results: In comparison to no internal filter, use of an in-line filter resulted in VO 2 measurements of 99%, 97%, 98%, and 97% during 50W, 100W, 150W, and 200W, respectively (Figure 1A). VO 2 /work slope measurements and measurements of minute ventilation were also highly consistent throughout exercise with and without use of an in-line filter (Figure 1B). Conclusions: Exercise testing is an integral part of cardiovascular care delivery. Our findings require further validation but suggest that an in-line filtration system can be utilized in an effort to reduce droplet and viral dissemination without impacting measures of cardiopulmonary performance.