Exercise testing to evaluate therapeutic interventions in chronic respiratory diseases
Luis Puente-Maestu 1, William W. Stringer 2, Richard Casaburi 2
1 Servicio de Neumología del Hospital Universitario Gregorio Marañón, Madrid, Spain; Instituto de investigación Sanitaria Gregorio Marañón, Madrid, Spain; Facultad de Medicina de la Universidad Complutense de Madrid, Madrid, Spain; 2 Rehabilitation Clinical Trials Center, Los Angeles BioMedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA; Geffen School of Medicine at UCLA. Los Angeles, CA, USA
*Correspondence: Luis Puente-Maestu, Email not available
Abstract
From an evidence-based perspective, performance during standardised exercise testing is of considerable importance in the multidimensional evaluation of most respiratory diseases. In this review we aim to summarise the available evidence on the responsiveness of exercise tests to various pharmacological and non-pharmacological therapeutic interventions, as well as the underlying mechanisms associated with the improvements. A standard test to evaluate interventions has not yet been defined and therefore there are several available formats with different types of responsiveness to interventions. Thresholds for clinically important changes are available for several tests. The mechanism of improvement is different depending on the disease process: when moderate or severe airflow limitation is present, as in chronic obstructive pulmonary disease (COPD), the primary mechanisms are reduced ventilatory requirement and/or enhanced ventilatory capacity via reduction of dynamic hyperinflation; in pulmonary arterial hypertension the effect of treatment is typically associated to haemodynamic improvement, while in interstitial lung diseases, the amelioration of arterial oxygen desaturation seems to be the predominant physiological factor.
