The risk of patients with rheumatoid arthritis (RA) developing dementia or heart failure has declined significantly since the 1980s, new research has shown.
Two groups of researchers from the Mayo Clinic, USA, carried out population-based studies in Minnesota to assess the incidence of dementia or heart failure over time in people with RA, and compared to the general population.
Rheumatoid arthritis is a long-term condition that causes pain, swelling, and stiffness in the joints. The condition usually affects the hands, feet, and wrists. Heart failure is one of the most common cardiovascular conditions in people with RA, and previous studies have suggested that people with RA are twice as likely to develop heart failure as people in the general population without RA.
For dementia, previous studies have delivered mixed results about the pattern of cognitive impairment and dementia in people with RA compared to the general population – with some showing increased odds, while others show the reverse. Furthermore, existing studies have not evaluated trends in incidence of dementia or heart failure to see if the risks have changed over time.
The risk of dementia in RA patients
Vanessa Kronzer, from the Mayo Clinic, and colleagues assessed the incidence of dementia over time in people with RA and compared it to that seen in the general population.
Medical record data were collected for 895 people diagnosed with RA between 1980 and 2009. All individuals were followed until death, migration, or 31 December 2019 to see if they went on to develop dementia. The ten-year cumulative incidence of dementia in people diagnosed during the 1980s, 1990s, and 2000s was 12.7%, 7.2%, and 6.2%, respectively – showing a clear decline and markedly lower cumulative incidence of dementia for people diagnosed with RA in the 2000s compared with the 1980s.
For 880 people in the general population without RA, the ten-year cumulative incidence of dementia in the 1980s, 1990s, and 2000s was 9.3%, 5.0%, and 7.1%, respectively. Overall, the risk of dementia in RA patients was significantly higher than in people without RA. When subdivided by decade, the risk of dementia in people diagnosed with RA was higher than non-RA comparators in the 1980s and 1990s-but not the 2000s.
Decline in heart failure risk
Elena Myasoedova and colleagues used the same methods to look at the trends of heart failure in 905 people diagnosed with RA between 1980 and 2009, and followed until death, migration, or 31 December 2019.
The ten-year cumulative incidence of heart failure in people diagnosed with RA in the 1980s, 1990s, and 2000s was 8.5%, 10.8%, and 7.1%, respectively. These results show there was no difference in incidence of heart failure in the 1990s and 2000s compared to the 1980s. For 903 people in the general population without RA over the same time period, the incidence of heart failure was 7.4%, 7.5%, and 7.3%.
When comparing the risk of heart failure in people with and without RA, those diagnosed with RA in the 2000s had no excess risk of heart failure compared to the general population. This finding contrasts with the two-fold excess risk seen in people diagnosed with RA in the 1980s, and around a 1.5-fold increased risk in 1990s.
Researchers have said that further studies are needed to investigate these associations, and look at the role of inflammation, autoimmunity, and anti-rheumatic treatments in the risk of dementia and heart failure.