Pneumonia Mortality Risk Increases with High RA Disease Activity

______________

A diagnosis of rheumatoid arthritis does not increase the risk of death in patients hospitalized for pneumonia, unless disease activity from rheumatoid arthritis is not adequately controlled, shows a study published in RMD Open.

Patients with rheumatoid arthritis face a greater risk of death than the general population, and the major causes include cardiovascular disease and infections, particularly pneumonia. However, it has been unclear whether the increased number of patients with rheumatoid arthritis dying from pneumonia is due solely to increased risk of acquiring infections or if, once infected, they also have worse outcomes. Rheumatoid arthritis could influence the outcomes of pneumonia due to the disease activity itself, its related comorbidities or its treatment, particularly immunosuppressive therapy.

To gain a better understanding of how rheumatoid arthritis or its treatment impacts on survival in patients with pneumonia, researchers from Aarhus University Hospital, Aarhus, Denmark analysed data from medical registries on 52,577 patients hospitalised in Jutland, Denmark, of which 1220 patients (2.3%) had rheumatoid arthritis.

The results showed that a diagnosis of rheumatoid arthritis had little impact on 90-day mortality; mortality rates after 90 days were 19.9% for patients with rheumatoid arthritis and 18.9% for patients without the condition (adjusted hazard ratio 1.05; 95% confidence interval 0.92-1.19).

“Rheumatoid arthritis patients do not have a higher mortality following hospitalization than patients without rheumatoid arthritis,” said Dr Mette Holland-Fischer, head of the department of rheumatology at Aalborg University Hospital, Aalborg, Denmark.

The researchers also looked at whether mortality rates varied according to the different rheumatoid arthritis treatments taken by patients. “Reassuringly, treatment with biologics and csDMARDs, either as a monotherapy or in combination, did not predict increased pneumonia mortality,” she added.

Patients with high disease activity are more likely to be treated with prednisolone, conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) and biologics which are associated with a risk of infections. “If patients with untreated RA disease activity

have similar or even worse infection outcomes as patients receiving immunosuppressive drugs, this would support the strategy of intensive treatment even in patients with rheumatoid arthritis prone to infections,” Dr Holland-Fischer explained.

The study found that patients receiving no rheumatoid arthritis treatment, indicating that they were either in remission or that their disease was uncontrolled, had 90-day mortality rates more than a third higher than rates in patients treated with methotrexate monotherapy.

However, recent use of prednisolone to control rheumatoid arthritis flare ups was found to be associated with increased mortality.

“Rheumatoid arthritis patients with at least one prescription for prednisolone within 3 months prior to hospitalization had a more than 40% increased 90-day all-cause mortality compared with RA patients treated with methotrexate,” said Dr Holland-Fischer.

Flare ups of rheumatoid arthritis are frequently treated with prednisolone, and the researchers were able to compare pneumonia outcomes in patients with rheumatoid arthritis who had used prednisolone treatment with those with a similar level of disease activity. This revealed that the increased mortality risk was not related to use of prednisolone.

“Our study reveals that high preadmission rheumatoid arthritis disease activity predicts increased mortality following hospitalized pneumonia regardless of prednisolone use,” she said.

C reactive protein (CRP) levels are an accepted marker of disease activity in rheumatoid arthritis and high CRP levels (≥20 mg/L) were associated with an almost fivefold increase in 90-day mortality compared with CRP levels <8 mg/L.

The study showed that the clinical focus to prevent poorer outcomes in rheumatoid arthritis following hospitalization for pneumonia should be on the risk of uncontrolled disease activity, Dr Holland-Fischer said. “If rheumatoid arthritis patients with high disease activity are treated more aggressively to obtain remission/low grade disease activity, this might lead to better outcomes for rheumatoid arthritis patients with infections.

“So in other words: disease activity is more dangerous than the rheumatoid arthritis-treatment itself.”

__________________

REFERENCE

Mette Holland-Fischer, Reimar W Thomsen, Ulrik Tarp, and Mette Nørgaard. "Prognosis of pneumonia in patients with rheumatoid arthritis: the role of medication and disease activity prior to admission a population-based cohort study," RMD Open. Published online 2020 Feb 10. doi: 10.1136/rmdopen-2019-001102