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

BACKGROUND AND AIM: 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. MATERIALS AND METHODS: 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 SpO(2), heart rate (HR), respiratory rate, blood pressure, exertion, and dyspnea on the modified-Borg scale. RESULTS: Noninferiority was established for SpO(2) (P < 0.05), systolic blood pressure (SBP; P < 0.001), and diastolic blood pressure (DBP; P < 0.05), but not for HR (P = 0.3) and respiratory rate (P = 0.6). The difference between the pretest and posttest (delta change) values for the parameters SpO(2), respiratory rate, HR, SBP, and DBP correlated significantly (P < 0.001) with Pearson correlation coefficient (r = 0.764, 0.783, 0.473, 0.838, and 0.783, respectively). The delta change values of modified-Borg scale for dyspnea (P = 0.291) and exertion (P = 0.208) were statistically insignificant between the two exercise tests. However, the correlation between the tests was statistically significant (P < 0.001). CONCLUSION: M2ST, a timesaving, cost-effective, and easy to perform exercise stress test, has been identified as a reliable alternative for 6MWT.