Risk of Death High for IPF Patients Soon After Acute Flare, Study Says
People with idiopathic pulmonary fibrosis (IPF) have shorter survival times after an acute exacerbation than do those with other interstitial lung diseases (ILD), often dying within a few months of such flares, a study from Finland reports.
Pulmonary fibrosis, or lung scarring, was the most common underlying cause of death in all these patients, indicating that the extent of lung disease is likely what affects survival the most.
The study, “Prognosis and causes of death of patients with acute exacerbation of fibrosing interstitial lung diseases,” was published in the journal BMJ Open Respiratory Research.
ILD comprises a group of diseases that cause progressive scarring of lung tissue, compromising respiratory function and blood oxygenation. In the most common form, IPF, the exact cause of the disease is unknown.
A sudden worsening of disease symptoms is known to increase the mortality of IPF patients, with most living about one to four months after such an acute exacerbation. But whether acute flare also raise mortality rates among people with ILDs other than IPF is not clear.
A team led by researchers at the University of Oulu examined data from 128 ILD patients who were hospitalized for an acute disease exacerbation between Jan. 1, 2008, and Dec. 31, 2017.
Most had IPF (79 patients), followed by ILD associated with rheumatoid arthritis (17 patients), and asbestos exposure (11 patients).
Many patients (56%) were treated in a respiratory ward — not in an intermediate or intensive care unit — and did not require mechanical ventilation to help with breathing. Of 16 patients (13%) who did need invasive mechanical ventilation, six survived.
The team found that people with IPF lived a median of 2.6 months after being hospitalized for an acute exacerbation, while those with other ILDs survived a median of 21 months. This difference remained significant even after adjusting for factors like age, gender, smoking, and lung function at the time of diagnosis.
This finding was in line with earlier reports “of median survival times ranging between 1 and 4 months” for IPF patients after an acute flare, the study noted.
When the use of corticosteroids before hospital admission was taken into account, an even higher risk of death was seen for IPF patients — 2.86 times higher compared with other ILDs. This finding supports “previous guidelines according to which corticosteroids or other immunosuppressive medication is not recommended for IPF,” the researchers wrote.
Not all ILDs had the same survival rates, the researchers noted. Those with asbestosis (lung fibrosis due to asbestos exposure) and IPF have the poorest survival rates, and those with non-specific interstitial pneumonia have the most favorable prognosis.
The team also examined factors that best predicted a patient’s risk of death after an acute exacerbation. For ILDs other than IPF, risk factors included older age (above 80), a pattern of usual interstitial pneumonia , and long-term oxygen treatment before a hospital admission.
These factors, however, did not influence the risk of death in IPF patients. For this group, risk factors predicting a poorer prognosis included use of corticosteroids before admission, admission to an intermediate care unit, and treatment with steroids at doses higher than 150 mg per day.
In both groups of patients, pulmonary fibrosis was the most common underlying cause of death — 84% among those with IPF and 87% for those with other ILDs. It was also the most common immediate cause of death (45% and 49%), followed by infection in the lower respiratory tract (29% and 30%), and acute exacerbations (11% and 10%).
“Pulmonary fibrosis represents a fatal condition and proved to be the underlying cause of death in the majority of all [ILD] patients,” the researchers concluded.
Still, “a longer post-hospitalisation survival in patients with non-IPF in comparison with patients with IPF” was clearly evident, “a finding which has not been so explicit in previous studies,” they added.
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