The diagnostic delay which prevents early intervention in patients with PAH is not improving over time, according to data from the Pulmonary Hypertension Society of Australia and New Zealand registry between 2004 and 2017
The evidence from a cohort of more than 2,000 patients was that the mean diagnostic interval was 2.5 years.
More than a third of patients (35%) were diagnosed after more than two years from symptom onset.
“When stratified by the year of diagnosis, there was no improvement in diagnostic interval across the study period. Subpopulations of SSc-PAH and HPAH also demonstrated no improvement in diagnostic interval over time,” the study said.
The study also found a longer diagnostic interval was associated with decreased survival.
The 5-year survival was 70% if diagnosed within 1 year of symptom onset, 66% if diagnosed at 1-2 years, and 61% if diagnosed after two years.
“After adjustment for age, gender and PAH subtype, a diagnostic delay of 2 years increased mortality rates by 11% (95% CI: 5–17%), while a delay of 5 years increased mortality by 29% (95% CI: 12–47%).”
Diagnostic delay was also associated with poorer 6MWD and measures of pulmonary function (DLCO, FEV1 and FVC).
It found older age, CHD-PAH subtype, the presence of peripheral vascular disease and obstructive sleep apnoea were independent predictors of longer diagnostic interval.
The authors, including respiratory physician Associate Professor Edmund Lau from the University of Sydney and Royal Prince Alfred Hospital, said the lack of improvement in diagnostic interval was disappointing given the availability of targeted therapy.
“This was a surprising result considering there has been greater general awareness of PAH in the community, and greater emphasis on screening in SSc-PAH and HPAH.”