Pulmonary hypertension triples mortality risk in AAV: Study
PH may be more common with AAV than thought — about 1 in 7 cases
Developing pulmonary hypertension (PH), which occurs when pressure in the blood vessels that supply the lungs becomes too high, more than triples the mortality risk among people with ANCA-associated vasculitis (AAV), a study finds.
PH may be relatively more common in AAV patients than understood, occurring in about 1 in 7 cases. While there may be many causes, the most common may be left-sided heart disease or lung disease.
“Our study provides important insight into the prognostic importance of PH in AAV, regardless of the cause or classification,” the researchers wrote in “Pulmonary hypertension in ANCA-associated vasculitis: a retrospective analysis,” which was published in Sarcoidosis, Vasculitis and Diffuse Lung Diseases.
AAV is an autoimmune disease that causes inflammation and damage to small blood vessels, most often in the kidneys and lungs. Someone with AAV is more likely to develop cardiovascular disease, especially in the months after a diagnosis.
Pulmonary hypertension “has rarely been described in patients with AAV,” wrote the researchers at Mayo Clinic Rochester, Minnesota, who sought to find out more about the frequency and causes of PH in AAV by reviewing the medical records of 655 adults who visited their clinic from 1997-2015 and had undergone an echocardiogram. An echocardiogram is a noninvasive scan that looks at the heart and its nearby blood vessels. It can help assess the probability of having PH and its results correlate well with those of right heart catheterization, an invasive test that’s the gold standard for diagnosing it.
Exploring causes of PH in AAV
A total of 97 patients (14.8%) were diagnosed with PH based on an echocardiogram at a mean age of 70.5. More than half (62.9%) were men. All but three had at least one risk factor for PH, and nearly three-quarters (73.2%) had multiple risk factors.
The most common possible cause of PH was left-sided heart disease, with valvular heart disease as the most common type, affecting almost half (41.2%) of patients. Valvular heart disease occurs when any of the heart’s valves, or small flaps, become damaged and no longer stop blood from flowing the wrong way.
The second most common likely cause was chronic lung disease. This included obstructive sleep apnea, when breathing pauses during sleep (28.9%); interstitial lung disease, marked by lung scarring (24.7%); and chronic obstructive pulmonary disease, characterized by blocked airways (22.7%).
Most (82.5%) received a diagnosis of AAV before a PH diagnosis, while 11 (11.3%) were diagnosed with AAV and PH at the same time. Only four (4.1%) received a PH diagnosis before being diagnosed with AAV. The timing of diagnosis was unclear for two patients.
Compared with those without PH, those with it were significantly older when diagnosed (mean age, 63 vs. 54), were more likely men (62.9% vs. 49.5%), and current or former smokers (60.9% vs. 47.9%). They also had a higher rate of kidney involvement (71.1% vs. 48%).
The patients were followed for a median of 18.6 months, or about 1.5 years, after a PH diagnosis. Most (73.2%) died a median 25.9 months (about 2.2 years) after being diagnosed.
After an AAV diagnosis, patients in the PH group were followed for a median of seven years and those in the non-PH group were followed for a median of 10 years.
AAV patients with PH had a significantly higher risk of death, by three times, than those without PH. Aside from PH, older age at diagnosis, being a man, having a history of smoking, and having kidney involvement were each independent risk factors for death in AAV patients.
“In this single-center retrospective cohort study, we found that PH is relatively common in patients with AAV, is often associated with left heart or lung disease, and is associated with an increased risk of death,” the researchers wrote, adding along with “identifying PH as an independent prognostic factor associated with a [threefold] higher risk of death,” other identified prognostic factors included age, male sex, smoking history, and kidney involvement. More research and following AAV patients over time is “warranted to determine the [underlying mechanisms] and accurate classification of PH in AAV,” they said.
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