A 6 minute walk test (6MWT) may be an inexpensive and effective way to follow changes in pulmonary hemodynamics in patients with chronic thromboembolic pulmonary hypertension (CTEPH), according to a study published by Respiratory Care.
The researchers identified and recruited 31 individuals (27 women, 4 men) at Chiba University Hospital in Japan to evaluate retrospectively the relationship between 6-minute walking oxygen desaturation-resaturation patterns and heart rate response in individuals with mild to severe CTEPH.
The following parameters were found in individuals with severe CTEPH compared with individuals with mild CTEPH:
- Significantly longer heart rate acceleration time (144.9±63.9 seconds vs 96.0±42.5 seconds, P =.003)
- Lower change in heart rate (47.4±16.9 beats vs 61.8±13.6 beats, P =.02)
- Lower heart rate recovery during the first minute after 6MWT (13.3±9.0 beats vs 27.1±9.2 beats, P <.001)
- Longer oxygen saturation reduction time (178.3±70.3 seconds vs 134.3±58.4 seconds, P =.025)
- Longer oxygen saturation recovery time (107.6±35.3 seconds vs 69.8±32.7 seconds, P =.004)
- Shorter distance in 6MWT (378.1±66.8 meters vs 462.6±52.6 meters, P =.002)
Limitations of this study included the small sample size and disproportionate number of women vs men. In addition, this study was conducted retrospectively and included only participants who had documentation of specific testing in their charts.
Researchers concluded that a predominate association was found in this study between pulmonary hemodynamics in individuals with CTEPH with changes in heart rate and oxygen saturation patterns observed during the 6MWT.
Further, clinicians should consider observing patterns in heart rate and oxygen saturation changes during a 6MWT in individuals with CTEPH, as it is a safe, convenient, and inexpensive method for following changes in pulmonary hemodynamics.
Disclosures: Dr Tanabe has received financial support from Actelion Pharmaceuticals and Pfizer. Drs Jujo and Tanabe belong to the Endowed Department, which is sponsored by Actelion.
Inagaki T, Terada J, Yahaba M, et al. Heart rate and oxygen saturation change patterns during 6-min walk test in subjects with chronic thromboembolic pulmonary hypertension [published online December 26, 2017]. Respir Care. doi:10.4187/respcare.05788