PAH: Looking for Zebras

Experts have always speculated that pulmonary arterial hypertension (PAH) patients who are diagnosed earlier tend to fare better than those who present later in the course of their illness. For example, we know that children are more likely than adult idiopathic PAH patients to respond to acute vasodilator testing. Whether this indicates that younger patients have a more active vasodilatory component and less “fixed” disease is not known definitively, but supports the notion that later onset disease may have been latent well before symptoms emerge. We also have research to support the benefit of treating patients earlier. Unfortunately, experts now know that even with the emergence of cardiorespiratory symptoms, there is still a severe delay in the time to diagnosis. If early diagnosis can lead to earlier initiation of targeted treatment for PAH, then we need to focus on what the major barriers are to achieving timely diagnosis in the modern treatment era.

In this issue of Advances, authors emphasize the high frequency of delay in diagnosis, which remarkably has not changed despite the major advances in medical therapy over the past 2 decades. Authors also highlight the role of both the patient and practitioner in delayed diagnosis. In a disease that often presents with symptoms that mimic other more common disease states—the so-called zebra—coupled with the reality that many physicians trained before the current era of novel therapies, the PAH patient often falls victim. Only through education and advocacy can we raise awareness and put the diagnosis of PAH on the minds of the front-line practitioners who usually see the patient long before they meet a PH expert. With Dr Greg Elliott's commitment to the PHA's early diagnosis campaign, he has guest edited a terrific edition of Advances in which authors help us to understand why delays in diagnosis occur, and emphasize that although PAH is a rare disease, it's one we can't afford to miss.