Performance of the 2-minute stand up test and the association with peak oxygen consumption in cardiopathes

Abstract

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): Fundo de amparo a pesquisa do estado da Bahia. Introduction The two minute sit-to-stand test (STST) quantifies the getting up and sitting down movement in 2 minutes. Its use has not yet been well established in patients with heart disease. Purpose To develop and validate an equation to estimate peak oxygen uptake (peak VO2) based on performance in STST. Methods Cross-sectional study with patients over 18 years with heart disease referred to a cardiovascular rehabilitation program, who were submitted to STST and Cardiopulmonary Exercise Test. Pearson's correlation analysis, multiple linear regression and ROC curve were used for statistical analysis. The association between determined and estimated peak VO2 was evaluated by the Bland-Altman analysis. p <0.05 was adopted as statistically significant. Results 158 participants were included, with a mean age of 60±14 years, 75.3% male, 75.6% with coronary artery disease and 24.4% with chronic heart failure. The average left ventricular ejection fraction was 57±16 %. The tests resulted in mean peak VO2 of 19.2±6.4 mL.kg-1.min-1, and mean STST performance was 32±12 repetitions. There was a correlation between peak VO2 and STST (r=0.65; R2=0.57; p<0.001). Performance on STST ≥ 32 was the best cutoff point to predict peak VO2 ≥ 20mL-kg-1min-1 (AUC = 0.80; 95%CI 0.74-0.87; p<0.001), sensitivity 71% (CI95 %; 0.58-0.81) and specificity 81% (95% CI; 0.69-0.89). The resulting equation was: peak VO2 = 21.4 - (0.16*age) + (0.26* STST) - (3.1*sex); male=0, female=1. The peak VO2 estimated by the equation (19.3±5.1 mL-kg-1min-1) was not different (p>0.05) from the peak VO2 determined (19.71±6.8 mL-kg-1min-1). Conclusions STST was moderately correlated with peak VO2. The validated equation accurately estimated the peak VO2. The STST is useful in the assessment of patients with heart disease, helping to estimate peak VO2 and identify patients with peak peak VO2peak ≥ 20mL-kg-1min-1.