People with rheumatoid arthritis are at a greater risk of irregular heart rhythm (known as atrial fibrillation) and stroke compared with the general population, finds a study published on bmj.com today.

Rheumatoid arthritis is already linked to an increased risk of heart attacks and heart failure, and is an important risk factor for stroke. But no study has yet examined whether it increases the risk of atrial fibrillation – a condition associated with an increased long term risk of stroke, heart failure, and death.

So a team of researchers set out to examine the risk of atrial fibrillation and stroke associated with rheumatoid arthritis in the Danish population.

The study involved more than four million people, of which 18,247 had a diagnosis of rheumatoid arthritis. Participants were followed up for an average of five years, during which time cases of atrial fibrillation and stroke were recorded.

The results show that patients with rheumatoid arthritis had a 40% increased risk of atrial fibrillation compared with the general population (8.2 and 6 events per 1,000 person years respectively) with women at slightly higher risk than men. This corresponds to one new case of atrial fibrillation per 12 rheumatoid arthritis patients followed for 10 years after diagnosis.

Patients with rheumatoid arthritis also had a 30% increased risk of stroke compared with the general population (7.6 and 5.7 events per 1,000 person years respectively).

New guidelines recommend annual screening for cardiovascular risk factors in patients with rheumatoid arthritis, and this should include screening for atrial fibrillation, say the authors.

They also suggest that, as inflammation plays a role in the development of atrial fibrillation and stroke, inflammation control is crucial for patients with rheumatoid arthritis, “not only for the management of joint symptoms, but also to reduce the need for drugs with potential adverse cardiovascular effects and, ultimately, to diminish the inflammation driven atherothrombotic process.”