Prognosis still gloomy for idiopathic PAH

Jul 2 2015

By Eleanor McDermid, Senior medwireNews Reporter

Analysis of the REVEAL registry shows poor 5-year outcomes for patients with pulmonary arterial hypertension (PAH), despite improvements due to targeted therapies.

The study also demonstrates the close association between New York Heart Association functional class and survival.

“These data reinforce the importance of continuous monitoring of [functional class] in patients with PAH”, say Harrison Farber (Boston University School of Medicine, Massachusetts, USA) and co-researchers.

The 5-year survival rates of 2039 previously diagnosed patients in the REVEAL registry were 88.0%, 75.6%, 57.0% and 27.2% for those in functional classes I, II, III and IV, respectively. The corresponding rates among 710 newly diagnosed patients were 72.2%, 71.7%, 60.0% and 43.8%.

Overall, 5-year survival was better than prior to the introduction of targeted therapies, when only about a third of patients survived that long, say the researchers, but they still describe patients’ prognosis as “poor”.

Survival was slightly worse in newly diagnosed than previously diagnosed patients, at 61.2% versus 65.4%. The researchers say this is partly due to survival bias resulting in a higher proportion of functional class III/IV among the newly diagnosed patients.

However, survival was better among newly diagnosed patients in these classes than in those previously diagnosed. The team suggests this is because previously diagnosed patients with advanced disease have already been treated and thus have fewer therapeutic options remaining to them, whereas newly diagnosed patients “represent a treatment-naïve population with greater opportunity to improve with PAH-specific therapy.”

Indeed, 27.5% of newly diagnosed patients improved their functional class between study enrolment and 12 months, compared with 14.3% of previously diagnosed patients.

By contrast, newly diagnosed patients in functional classes I and II had worse survival than previously diagnosed patients, in line with previous research showing a high mortality risk at the time of diagnosis.

This suggests that “a relatively favorable risk profile at diagnosis reflects earlier diagnosis but does not necessarily guarantee a good outcome”, write Farber et al in CHEST.

“Thus, treatment should be initiated as early as possible as newly diagnosed patients are at greatest risk and have the greatest opportunity to show functional improvements.”

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