Measuring ventilatory efficiency through the end of exercise (V˙E/V˙CO2-total) in healthy athletes frequently exceeded the prognostic threshold of 34 (13%), compared to 1.9% using V˙E/V˙CO2-start-VT1.
Cohort (n=521)
No
How do different methods of measuring ventilatory efficiency (V˙E/V˙CO2) during CPET affect the proportion of healthy athletes exceeding established prognostic thresholds?
Measuring ventilatory efficiency over the entire exercise effort in healthy athletes frequently results in values exceeding established prognostic thresholds, suggesting that alternative measurement methods (like start-VT1 or Nadir) may be more appropriate to avoid false-positive assessments for pathology.
Absolute Event Rate: 13% vs 1.9%
Ventilatory efficiency (V˙E/V˙CO2) during exercise is defined as the ratio of minute ventilation (V˙E) and carbon dioxide output (V˙CO2) and reflects matching of alveolar ventilation and pulmonary perfusion as well as ventilatory drive.1 Abnormally high V˙E/V˙CO2 is important diagnostically and prognostically in the setting of cardiopulmonary disease.1 Current clinical guidelines propose a total slope (V˙E/V˙CO2-total) 90th percentile for predicted V˙E/V˙CO2-total,6 and predicted V˙E/V˙CO2-Nadir +(1.66 × SD).4 Statistical analyses were performed using R (R Core Team, Vienna, Austria, 2022). This study was approved by the Massachusetts General Brigham Institutional Review Board. In 521 athletes (age = 38 ± 15 years, 33% female, 91% white), exercise was completed on the treadmill in 292 (56%) and cycle ergometer in 229 (44%). Most participants were endurance athletes (n = 330, 63%), with the remaining participating in mixed/other sports (n = 191, 37%). Table 1 presents V˙E/V˙CO2 and pV˙O2stratified by age and sex. V˙E/V˙CO2-total exceeded the guideline-recommended cutoff of 30 in 66/172 (38%) females and 106/349 (30%) males and exceeded the prognostic threshold of 34 in 30/172 (17%) females and 40/349 (11%) males. In the total population, V˙E/V˙CO2 exceeded the prognostic threshold of 34 in 70/521 (13%) athletes using V˙E/V˙CO2-total, 10/521 (1.9%) using V˙E/V˙CO2-start-VT1, and 2/521 (0.4%) using V˙E/V˙CO2-Nadir. Of the 70 athletes with V˙E/V˙CO2-total >34, only 8/70 (11.4%) had V˙E/V˙CO2-start-VT1 > 34 and 2/70 (2.9%) had V˙E/V˙CO2-Nadir >34 (Figure 1).
Petek et al. (Mon,) conducted a cohort in Healthy athletes (n=521). Measurement of ventilatory efficiency (V˙E/V˙CO2-total) vs. V˙E/V˙CO2-start-VT1 or V˙E/V˙CO2-Nadir was evaluated on V˙E/V˙CO2 exceeding the prognostic threshold of 34. Measuring ventilatory efficiency through the end of exercise (V˙E/V˙CO2-total) in healthy athletes frequently exceeded the prognostic threshold of 34 (13%), compared to 1.9% using V˙E/V˙CO2-start-VT1.
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