# The five times sit-to-stand test predicts achievable exercise intensity during stress echocardiography

## TL;DR

The 5-STS test helps predict how much exercise a patient can handle during a heart stress test, improving test accuracy for people with physical limitations.

## Contribution

The 5-STS test is shown to be a simple and effective predictor of achievable exercise intensity during stress echocardiography.

## Key findings

- A 5-STS cut-off of 11.7 s predicted achieving a 25 W load with high sensitivity and specificity in the derivation cohort.
- In the validation cohort, a 12.0 s cut-off demonstrated 98% sensitivity and 88% specificity for predicting achievable load.
- Sarcopenia-related indices like 5-STS predicted exercise intensity independently of age and sex.

## Abstract

Exercise stress echocardiography (ESE) is becoming increasingly important in assessing heart failure and valvular diseases; however, determining optimal exercise intensity remains challenging, particularly in patients with physical disorders.

A total of 94 patients scheduled for ESE were enrolled in the study. Physical capability was assessed using the five times sit-to-stand test (5-STS), Clinical Frailty Scale, acronyms of the five components, namely strength, assistance with walking, rising from a chair, climbing stairs, and falls (SARC-F) questionnaire, grip strength test, and bioelectrical impedance analysis. In the derivation cohort (n = 43), we determined the 5-STS cut-off value to achieving a 25 W load. The effectiveness of this cut-off value was prospectively evaluated in a validation cohort (n = 51). In the derivation cohort, the 5-STS predicted achieving a 25 W load using a cut-off of 11.7 s with 91% sensitivity and 70% specificity. In the validation cohort, using 12.0 s as the cut-off demonstrated 98% sensitivity and 88% specificity. The multivariate analysis identified age, sex (female), brain natriuretic peptide, SARC-F, and 5-STS as independent predictors of maximum achieved load. In a multivariate model including bioelectrical impedance parameters, lower limb muscle mass independently influenced maximum achievable load, regardless of age. Patients with optimized 5-STS-based load selection achieved significantly higher peak heart rates and maximum loads than those without.

Sarcopenia-related indices, particularly the 5-STS, effectively and simply predicted achievable exercise intensity during ESE, independent of age and sex. The use of these indices to determine the initial load may help optimize ESE protocols for individual patients.

Graphical Abstract