Comparison of master two-step exercise stress test versus six-min walk test in patients tested positive for SARS-CoV-2.

Abstract

There has been a lack of uniformity on how to triage coronavirus disease 2019 (COVID-19) patients visiting the emergency units of hospitals. Triage tools are themselves spreading the pandemic in hospital areas. The present study compared a master two-step (M2ST) exercise stress test versus a 6-min walk test (6MWT) in COVID-19-positive patients visiting the emergency unit of a hospital. Thirty-nine patients underwent 6MWT followed by M2ST, while another set of 38 patients underwent M2ST followed by 6MWT in this randomized, crossover, open-label, and noninferiority study. The exercise tests assessed the change from baseline in SpO₂, heart rate (HR), respiratory rate, blood pressure, exertion, and dyspnea on the modified-Borg scale. Noninferiority was established for SpO₂ (<i>P</i> < 0.05), systolic blood pressure (SBP; <i>P</i> < 0.001), and diastolic blood pressure (DBP; <i>P</i> < 0.05), but not for HR (<i>P</i> = 0.3) and respiratory rate (<i>P</i> = 0.6). The difference between the pretest and posttest (delta change) values for the parameters SpO₂, respiratory rate, HR, SBP, and DBP correlated significantly (<i>P</i> < 0.001) with Pearson correlation coefficient (<i>r</i> = 0.764, 0.783, 0.473, 0.838, and 0.783, respectively). The delta change values of modified-Borg scale for dyspnea (<i>P</i> = 0.291) and exertion (<i>P</i> = 0.208) were statistically insignificant between the two exercise tests. However, the correlation between the tests was statistically significant (<i>P</i> < 0.001). M2ST, a timesaving, cost-effective, and easy to perform exercise stress test, has been identified as a reliable alternative for 6MWT.