Six-minute walk distance predicts VO₂ (max) in patients supported with continuous flow left ventricular assist devices

Int J Artif Organs. 2014 Jul 31;37(7):539-45. doi: 10.5301/ijao.5000345. Epub 2014 Jul 18.

Abstract

Background: Six-minute walk distance (6MWD) and maximal oxygen uptake (VO₂ max ) are used as prognostic tools in patients with heart failure (HF). Whether these tests provide similar information in the LVAD population is not known.

Methods: Eight patients supported with VentrAssist rotary blood pump LVADs, underwent three days of testing that included 6MWD and VO₂ max at normal, high or low speeds, generating twenty-four paired results.

Results: The mean 6MWD was 438 (+/- 90 SD) m and the mean VO₂ (max) was 14.12 (+/-1.87) ml/kg/min. There was a modest correlation between VO₂ (max) and 6MWD (r = 0.56 p = 0.004), which improved (r = 0.72 p = 0.002) when patients with higher resting Pro BNP levels and larger left ventricular end diastolic diameters (LVEDD) were excluded.

Conclusions: 6MWD is correlated with VO₂ (max) in LVAD supported patients, with higher correlations in patients with better underlying cardiac function.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Exercise Test*
  • Female
  • Heart Failure / physiopathology*
  • Heart Failure / therapy
  • Heart-Assist Devices*
  • Humans
  • Male
  • Middle Aged
  • Oxygen Consumption / physiology*
  • Prognosis
  • Young Adult