Cardiopulmonary Exercise Testing in Heart Failure

A growing body of literature has underscored the value of ventilatory gas exchange techniques during exercise testing (commonly termed cardiopulmonary exercise testing, or CPX) and their applications in the management of patients with heart failure (HF). The added precision provided by this technology is useful in terms of understanding the physiology and mechanisms underlying exercise intolerance in HF, quantifying the response to therapy, evaluating disability, making activity recommendations, and quantifying the response to exercise training. Importantly, a wealth of data has been published in recent years on the prognostic utility of CPX in patients with HF. These studies have highlighted the concept that indices of ventilatory inefficiency, such as the VE/VCO₂ slope and oscillatory breathing, are particularly powerful in stratifying risk in HF. This article provides an overview of the clinical utility of CPX in patients with HF, including the applications of ventilatory inefficiency during exercise, the role of the pulmonary system in HF, respiratory muscle performance (RMP), and the application of CPX as part of a comprehensive clinical and exercise test evaluation.Gerald F. Fletcher, MD, FAHA, FACC: HF continues to be a worldwide health care burden. With this burden, there are often many complicated and expensive diagnostic procedures and tests performed. The authors herein describe and discuss in clear detail the use of CPX to evaluate patients with HF. Such testing is noninvasive, relatively inexpensive, and provides, as the authors clearly discuss, much diagnostic and prognostic data to the clinician with the means to improve overall patient care. In addition, the authors provide clear insight into the value of CPX use in concert with the standard electrocardiographic exercise test, as such is not always done as part of the exercise evaluation in subjects with cardiovascular disease or pulmonary disease or both.