Risk of atrial fibrillation and stroke in rheumatoid arthritis: Danish nationwide cohort study

BMJ: Jesper Lindhardsen, research fellow1, Ole Ahlehoff, research fellow1, Gunnar Hilmar Gislason, research director1, Ole Rintek Madsen, research director2, Jonas Bjerring Olesen, research fellow1, Jesper Hastrup Svendsen, professor34, Christian Torp-Pedersen, professor1, Peter Riis Hansen, research director1 – March 8, 2012.

Abstract

Objectives To determine if patients with rheumatoid arthritis have increased risk of atrial fibrillation and stroke.

Design Longitudinal nationwide register based cohort study.

Setting Inpatient and outpatient hospital care in Denmark from 1997 to 2009.

Participants Entire Danish population aged over 15 years without rheumatoid arthritis, atrial fibrillation, or stroke before 1997. Participants with rheumatoid arthritis were identified by individual level linkage of diagnoses and rheumatoid arthritis treatment.

Main outcome measures Rates of atrial fibrillation and stroke.

Results Of 4 182 335 participants included in the cohort, 18 247 were identified as having rheumatoid arthritis during follow-up, with a mean age at disease onset of 59.2 years and a median follow-up of 4.8 years. A total of 156 484 people, including 774 with rheumatoid arthritis, were diagnosed as having atrial fibrillation (age and sex matched event rates of 8.2 per 1000 person years in rheumatoid arthritis patients and 6.0 per 1000 person years in the general population), with an adjusted incidence rate ratio of 1.41 (95% confidence interval 1.31 to 1.51). Read More