We applaud the recent article in The Lancet Respiratory Medicine by Marius M Hoeper
and colleagues,1 which highlights a unique group of patients with pulmonary hypertension
who meet the diagnostic criteria for group 1 pulmonary arterial hypertension (PAH)
but have a lung phenotype characterised by older age, substantial smoking history,
male predominance, substantial reduction of diffusion capacity for carbon monoxide,
and a clinical course that is similar to group 3 pulmonary hypertension rather than
group 1.