Current biologic use but not previous biologic use decreases the risk of cardiovascular events in patients with inflammatory arthritis, Australian figures show.

The findings come from a study of data from more than 4,000 patients on the Australian Rheumatology Association Database (ARAD) with a diagnosis of rheumatoid arthritis, psoriatic arthritis or ankylosing spondylitis. Follow-up was for a median of five years.

It found cardiovascular event rate was decreased in those taking TNF inhibitors (HR=0.85) and other biologics (HR=0.81) but not in patients who had ceased biologic therapy (HR=0.96).

There was no significant difference in cardiovascular event rates between the three indications for treatment.

Co-morbid hypertension, hyperlipidaemia and diabetes were all significant positive predictors of cardiovascular events, along with increased age, male sex, regular smoking and higher disability scores.

The findings, published in Arthritis Research and Therapy, are largely consistent with other studies and support the theory that inflammatory processes driven by cytokines such as TNF can explain the two-fold increased risk of cardiovascular events in people with arthritis.

However the study authors said it was possible that tighter disease control achieved by biologic treatment rather than ‘an intrinsic effect of the biologic themselves’ might explain the improved cardiovascular outcomes.

There was no clear reason for the comparable rate of cardiovascular events in biologic naïve patients and those who had ceased biologics.

“This could be because those who had ceased biologic therapy were generally resistant to biologic therapy and thus did not derive any improvement in either disease status or the CVE rate, or it could be because any protective effect from biologic use is not sustained after biologic cessation and participants returned to their previous level of cardiovascular risk,” they wrote.

Co-author Dr Premarani Sinnathurai, from the Institute of Bone and Joint Research at the Kolling Institute in Sydney, told the limbic it was also unclear when the protective effect on cardiovascular events might be lost.

“Most of the medications have a fairly short half-life so you would think the actual effect of the medication would wear off quite quickly, but there are also other factors like how active their disease is and other risk factors that could contribute.”

She said the study could not adjust for the various reasons for ceasing medications such as lack of efficacy of the treatment or side effects.

“I’m sure they had a good reason for coming off in those who ceased their medication. But for me it emphasises the importance of maintaining good disease control in terms of their arthritis and so we would be unlikely to stop these medications unless we were confident we could maintain control of their inflammatory arthritis.”

Patients who had ceased methotrexate had a higher risk of cardiovascular events than those who had never taken it, while patients who had ceased prednisone or prednisolone had an increased cardiovascular risk compared to those who hadn’t used the medications.