Development of pulmonary hypertension (PH) in cystic fibrosis (CF) patients compromises lung function and blood-gas parameters, but does not significantly worsen survival, an analysis suggests.
The study, “Prognostic significance of pulmonary hypertension in patients with cystic fibrosis: A systematic review and meta-analysis,” was published in the journal Medicine. It was the result of joint work between researchers at the West China Hospital of Sichuan University and the Johns Hopkins University School of Medicine.
Cystic fibrosis is a genetic disease characterized by the buildup of thick, sticky mucus in the lungs and digestive system. The most common symptoms include progressive damage to the respiratory system and subsequent lung infections, as well as problems digesting food.
Pulmonary hypertension is frequently found in patients with advanced lung diseases like CF. Clinical evidence of PH in cystic fibrosis patients is an indicator of a worse prognosis and is associated with progression of the disease.
There are few studies available on the prevalence of PH among CF patients and its impact on disease outcome, and the studies that have been done included only a small sample size.
With this in mind, researchers sought to determine the influence of PH on the survival of cystic fibrosis patients by analyzing data from seven relevant clinical studies on 2,141 CF patients.
The results showed that although the survival rate was lower among patients with both PH and CF, the difference was not significant, compared to patients with only cystic fibrosis.
“By pooling all the studies and comparing the survival outcome of patients according to PH status, we observed that the [overall survival] was lower in CF patients with PH than those without, but the difference was not statistically significant,” the researchers wrote.
They emphasized, however, that the “presence of PH markedly correlated with worse blood-gas parameters and worse lung function in CF patients.”
Researchers found that patients with both diseases failed to oxygenate their blood properly and therefore had lower oxygen levels (hypoxemia) and higher carbon dioxide levels (hypercapnia) in their bloodstream, compared with patients without pulmonary hypertension. Patients with both diseases also had worse lung function.
“Our findings suggest that the presence of PH was strongly correlated with worse blood-gas parameters and worse lung function, but surprisingly had no significant prognostic value on survival among CF patients,” the team said.
According to the researchers, additional large-scale studies are necessary to confirm these findings.