Six-minute walk test in pulmonary arterial hypertension

Abstract

Exercise intolerance is the main characteristic of pulmonary arterial hypertension (PAH). The six-minute walk test (6MWT) and cardiopulmonary exercise test are widely used in assessing exercise capacity of PAH patients. Six-minute walk distance (6MWD) has been specified as the main clinical outcome in PAH and has been used as the primary end-point in many studies conducted for new PAH treatments. Using 6MWD as the end-point in clinical studies has many advantages. 6MWT is an inexpensive, easily applicable, and repeatable standardized test that is well-tolerated by PAH patients. Moreover, it is a valid measure of symptomatic improvement. It is correlated with variables of maximal cardiopulmonary exercise test as a measure of submaximal exercise capacity and disease severity markers such as functional class and pulmonary hemodynamics. It is widely used in clinical practice together with other invasive and non-invasive disease markers in assessing disease progression and response to treatment. In addition, it has prognostic importance and is a good prognostic marker. On the other hand, there are limitations to the use of 6MWD as the primary end-point in PAH treatment. It has decreased sensitivity in individuals with less severe disease and high 6MWD at baseline and decreased adequacy in assessing the effects of treatment in patients who are still under PAH treatment. Despite the limitations, 6MWD plays a key role in the evaluation and management of PAH patients.

Primary Endpoints in Pediatric Efficacy Trials Submitted to the US FDA

“…For example, the primary efficacy endpoint commonly measured in interventional pulmonary arterial hypertension trials in adults is the 6-minute walk test (6MWT), which is a measure of exercise capacity. [12][13][14] However, the 6MWT would not be a feasible endpoint to measure in infants and young children because they are not developmentally or physically capable of performing the test. 15,16 In other instances, the relatively small pediatric patient population available or the infrequency of endpoint events often make it unfeasible to incorporate the adult endpoint into a pediatric trial because of the sample size that would be required to achieve adequate statistical power to detect a difference.…”

Idiopathic pulmonary fibrosis in West Highland white terriers: An update

“…The 6MWT is a submaximal exercise test that measures the distance an individual is able to walk over 6 min (6MWD) (Lilja-Maula et al, 2014a). This test is used widely in human clinical practice to assess disease progression and response to treatment, as well as in therapeutic trials to serve as a primary end-point, as it is inexpensive, convenient and well-tolerated (Demir and Küçükoglu, 2015). In WHWTs with CIPF, the 6MWT distance was significantly decreased in comparison with controls and had a moderate positive correlation with PaO 2 , suggesting that the test can serve as a non-invasive means of monitoring lung function and exercise tolerance (Lilja-Maula et al, 2014a).…”

Geriatric Assessment for Older Adults with Sickle Cell Disease: protocol for a prospective cohort pilot study

“…The 6MWT is a test of aerobic endurance that has been well-validated in both geriatric and SCD populations; however, there are no data in older adults with SCD [14,38,39]. It is used in screening for pulmonary hypertension, a complication more common in older adults with SCD and is associated with increased mortality [10,40]. During the 6MWT, we will instruct the participant to "cover as much ground as possible" by walking for 6 minutes on a 20-meter walking course up-and-back and around 2 cones at each end of a quiet hallway in adult sickle cell clinic.…”