Detecting Small Airways Dysfunction in Asthma: Rationale, Findings, and Future of ATLANTIS

Small airway dysfunction (SAD) is both common and clinically relevant in patients with asthma. However, there is no recognized "gold standard" approach for the identification of SAD in clinical practice. The ATLANTIS (AssessmenT of smalL Airways involvemeNT In aSthma) study was a prospective (1-year follow-up), multicenter, international observational study that aimed to identify the best, or best combination of biomarkers, physiological tests, and imaging markers for the determination of the presence of SAD, and to evaluate the contribution of SAD across all asthma severities to meaningful clinical asthma outcomes. A large number of analyses from the ATLANTIS study have been conducted or are planned. This narrative review summarizes the key findings to date and the future directions. Perhaps the most important finding so far is that a "toolbox" of spirometry, oscillometry, and a small airways dysfunction questionnaire can detect SAD with high accuracy (area under the receiver operating characteristic curve 0.96 and positive likelihood ratio 12.8). Further, collaboration with other consortia has demonstrated the use of oscillometry to identify asthma phenotypes. We advocate the adoption of the ATLANTIS toolbox into interventional studies in asthma-and if validated, this could form a useful part of research and daily clinical practice.