Pulmonary hypertension increases the risk of cystic fibrosis patients’ lung function worsening, but is not a predictor of reduced survival, a study reports.
The research, ”Prognostic significance of pulmonary hypertension in patients with cystic fibrosis: A systematic review and meta-analysis,” was published in the journal Medicine.
In addition to chronic lung infections and bronchiectasis, CF patients can develop PH, which can lead to poorer outcomes.
In these patients, the main cause of PH is diminished oxygen levels in tissue, which leads to constriction of lung arteries and increased pulmonary blood vessel resistance. The destruction of lung tissue and associated loss of pulmonary blood vessels is another possible cause of PH in CF.
There have been few studies on the prognostic value of PH in CF patients, and the ones that have been done have had small sample sizes.
So a research team decided to do a combined analyze of the results of a number of studies to try to shed more light on the relationship between PH and CF patients’ survival.
The team also wanted to explore the correlation between PH and CF patients’ disease characteristics.
“To the best of our knowledge, this is the most comprehensive meta-analysis to assess the prognostic value of PH in CF,” they wrote.
Seven studies covering 2,141 patients were included in the analysis.
One finding was an association between PH and lower levels of oxygen arterial pressure. Another was a link between PH and higher carbon dioxide arterial pressure. The measures reflect the two substances’ content in blood.
In addition, the researchers found a correlation between PH and lower scores on two measures of lung function — forced expiratory volume in 1 second and forced vital capacity percentage. These measures showed a link between PH and the severity of lung function loss in CF, the team said.
The analysis did not reveal a link between PH and patients’ survival, however. As a possible explanation, the researchers noted that higher pulmonary arterial pressure in CF patients is usually mild in comparison with other forms of PH.
Future studies may help clarify if there is a difference in these findings between early- and late-stage disease, the team said.
“Our findings suggest that the presence of PH was strongly correlated with worse blood-gas parameters and worse lung function, but had no significant prognostic value on survival among patients with CF,” they concluded.