Author + information
- Thomas Thum, MD, PhD⁎ (, )
- Stefan von Haehling, MD, PhD and
- Stefan D. Anker, MD, PhD
- ↵⁎Molecular and Translational Therapeutic Strategies, Hannover Medical School, Carl-Neuberg-Str. 1, Hannover, Lower Saxony 30625, Germany
Afilalo et al. (1) report that an impaired gait speed (a simple measure of frailty) can be used to identify elderly patients at high risk of major in-hospital events after cardiac surgery. They defined the primary predictor slow gait speed as the time taken to walk 5 m in more than 6 s.
Gait speed is already an established marker of exercise capacity in the elderly (2), and thus the results of the study are not surprising. The overwhelming amount of previous studies including statements of consensus definitions for sarcopenia and cachexia in elderly and in chronically ill patients defines slow gait speed as a walking speed <0.8 m/s on the 4-m walk test (3,4). We thus were surprised to see that Afilalo et al. (1) used a different definition of slow gait speed and suggest using a 5-m walk test. For the 4-m gait speed test, a very large body of population-based data and normal values are available (from investigations in many thousands of subjects ). To reinvent the wheel may sometimes be a good idea, but it seems that this is not such an occasion, particularly not if we want our studies to be accepted outside of cardiology by general medicine and geriatrics; after all many of our patients are elderly. Afilalo et al. (1) suggest that a time of <6 s to walk 5 m is “normal” (i.e., >0.833 m/s), but where is the evidence of this? This small study with 131 patients cannot establish “normality.” Very large population-based studies found a cutoff of 0.8 m/s (3). We in cardiology should use these cutoffs as well, at least until we have proved that they are not useful in our patients (which seems doubtful). We suggest focusing on the use of the previous and established definition for the 4-m walk test in future trials. This would allow better comparability between previous, ongoing, and future studies in the field of frailty, sarcopenia, and/or cachexia in patients with heart disease as well as other chronic illnesses.
Regarding the survival analysis, we only want to state that according to their Table 1, it appears that many important parameters known to affect prognosis of such patients (including anemia, estimated glomerular filtration rate, body temperature, and plasma levels of natriuretic peptides) were not considered. Hence, we find the statement that gait speed (regardless of how it is measured) is an “incremental predictor of mortality and major morbidity” in elderly patients undergoing cardiac surgery too broad and likely wrong in selected patients. We believe that the value of using slow gait speed as a reliable marker for surgical or other outcomes in patients with cardiac illness still needs to be better defined.
- American College of Cardiology Foundation
- Afilalo J.,
- Eisenberg M.J.,
- Morin J.F.,
- et al.
- Buchner D.M.,
- Larson E.B.,
- Wagner E.H.,
- Koepsell T.D.,
- de Lateur B.J.