CUT-OFF VALUE FOR 30-SECOND SIT-TO-STAND TEST IN MYOCARDIAL INFARCTION

Abstract

BACKGROUND Functional exercise capacity is closely associated with the health trajectory of patients who experienced a myocardial infarction (MI). In the absence of gold standard tests, practical approaches such as the 30-second sit-to-stand test (30 s-STST) could be used. This study aimed to identify a 30 s-STST cut-off value characterizing functional exercise capacity. METHODS 22 MI patients were evaluated using the 6-minute walk test (6MWT) and 30 s-STST during the third day of their inpatient admission. Patients who covered <450 m in 6MWT were classified as “poor” exercise capacity, and patients who covered ≥450 m were classified as “good”. Receiver operating characteristics (ROC) curve analysis was performed to investigate the 30 s-STST ability to accurately classify exercise capacity. The Youden index was used to determine the optimal cut-off value for the 30 s-STST. Area under the curve (AUC) was interpreted as follows: <0.5 – no discrimination, 0.5–0.69 poor discrimination, 0.7–0.79 acceptable discrimination, 0.8–0.89 excellent discrimination, ≥ 0.9 extraordinary discrimination. RESULTS The optimal cut-off value was “12 repetitions” for 30 s-STST (sensitivity= 0.77; specificity= 0.67). Area under ROC curve was 0.77 (p < 0.05, %95 CI= [0.56 – 0.95]). Also, there was a significant correlation between 6MWT distance and 30 s-STST repetitions (r = 0.46; p < 0.05). CONCLUSION In patients who survived an MI, performing less than 12 repetitions in 30 s-STST indicated impaired functional exercise capacity. This cut-off value could be useful in identifying individuals that may require focused interventions to increase functional capacity.w