Kim Chul-Ho, Anderson Steve, Maccarter Dean, Johnson Bruce
Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN 55905, USA.
Pulm Med. 2012;2012:962598. doi: 10.1155/2012/962598. Epub 2012 Dec 31.
Patients with pulmonary arterial hypertension (PAH) and heart failure (HF) display many abnormalities in respiratory gas exchange. These abnormalities are accentuated with exercise and track with disease severity. However, use of gas exchange measures in day-to-day clinical practice is limited by several issues, including the large number of variables available and difficulty in data interpretation. Moreover, maximal exercise testing has limitations in clinical populations due to their complexity, patient anxiety and variability in protocols and cost. Therefore, a multivariable gas exchange index (MVI) that integrates key gas exchange variables obtained during submaximal exercise into a severity score that ranges from normal to severe-very-severe is proposed. To demonstrate the usefulness of this index, we applied this to 2 groups (PAH, n = 42 and HF, n = 47) as well as to age matched healthy controls (n = 25). We demonstrate that this score tracks WHO classification and right ventricular systolic pressure in PAH (r = 0.53 and 0.73, P ≤ 0.01) and NYHA and cardiac index in HF (r = 0.49 and 0.74, P ≤ 0.01). This index demonstrates a stronger relationship than any single gas exchange variable alone. In conclusion, MVI obtained from light, submaximal exercise gas exchange is a useful approach to simplify data interpretation in PAH and HF populations.
患有肺动脉高压（PAH）和心力衰竭（HF）的患者在呼吸气体交换方面存在许多异常。这些异常在运动时会加剧，并与疾病严重程度相关。然而，在日常临床实践中，气体交换测量的应用受到几个问题的限制，包括可用变量众多以及数据解释困难。此外，由于其复杂性、患者焦虑以及方案和成本的变异性，最大运动测试在临床人群中存在局限性。因此，提出了一种多变量气体交换指数（MVI），该指数将次最大运动期间获得的关键气体交换变量整合到一个从正常到重度 - 极重度的严重程度评分中。为了证明该指数的实用性，我们将其应用于两组（PAH组，n = 42；HF组，n = 47）以及年龄匹配的健康对照组（n = 25）。我们证明，该评分与PAH患者的WHO分类和右心室收缩压相关（r = 0.53和0.73，P≤0.01），与HF患者的NYHA分级和心脏指数相关（r = 0.49和0.74，P≤0.01）。该指数显示出比任何单个气体交换变量更强的相关性。总之，从轻度、次最大运动气体交换中获得的MVI是一种简化PAH和HF人群数据解释的有用方法。
