ACR: Mortality gap narrows between RA patients and general population

SAN FRANCISCO – Two population-based studies provide encouraging evidence that mortality, particularly cardiovascular mortality, is declining in people with rheumatoid arthritis.

The first study – conducted in British Columbia – showed that people diagnosed with rheumatoid arthritis (RA) during 2001-2006 had a lower risk of death, compared with the general population, than did those diagnosed during 1996-2000. The second study focused on cardiovascular death and also found declining death rates in people diagnosed with RA since 2000, compared with RA patients in previous decades.

Both studies suggest that improved detection and management of RA and improved vigilance in screening and managing cardiovascular disease risk factors have contributed to this decline. The studies were presented at the annual meeting of the American College of Rheumatology.

Canadian study

“The take-home message from our study is that with improved treatments and better ability to control inflammation in patients with RA, we are closing the mortality gap between RA patients and the general population. This is a reassuring message for patients and clinicians,” said lead investigator Dr. Diane Lacaille of the University of British Columbia, Vancouver.

Dr. Diane Lacaille

It has been recognized for decades that risk of death is higher in people with RA than in the general population, mainly due to an increased risk of cardiovascular disease and cardiovascular death, she noted.

“We have improved RA therapies to attack inflammation, and cardiovascular disease is also linked to inflammation, so we would expect improved mortality along with better treatments,” she continued.

The study compared two cohorts of RA patients with age- and gender-matched controls from the general population: early, those diagnosed with RA during 1996-2000, and late, those diagnosed during 2001-2006. All study subjects were followed from the onset of RA until death or for 5 years.

The entire RA cohort included almost 25,000 people, two thirds of them women, with a mean age of onset of 57 years.

Over the entire 10 years, there was about a 30% increased risk of death from cardiovascular disease, cancer, and infections in people with RA. The mortality was 24.43 per 1,000 person-years in RA participants versus 18.77 deaths per 1,000 person-years in controls, respectively.

When the late cohort of RA patients and controls were compared, the risk of death improved over time, whereas this was not the case in the early cohort. In the early cohort, there was a 64% increase in all-cause mortality, compared with controls. In the late cohort, there was no significant increase in risk of death in RA patients, compared with controls.

RA patients had a 66% increase in cardiovascular disease deaths when compared against controls in the early cohort, but there was no statistically significant increase in the comparison for the late cohort.

Overall, comparisons against controls showed that mortality in the late cohort improved significantly for cardiovascular disease and cancer, but not for infection. Dr. Lacaille speculated that there were too few cases of death due to infection to achieve significance.

“I should caution you that follow-up of 5 years is too short to conclude that there is no increased risk, but we can say that the gap is narrowing,” Dr. Lacaille concluded.

Focus on cardiovascular death

A second study looked for trends among 315 people diagnosed with RA during 2000-2007, 498 people diagnosed with RA in earlier years, and 813 controls without the disease. Participants were followed until death, or until they moved out of the region, or Jan. 1, 2014. These investigators found a decline since 2000 in cardiovascular deaths in people with RA, compared with RA patients in earlier years and controls.

Dr. Elena Myasoedova

“The implications of our study appear to be broad, that is, there is a beneficial trend in cardiovascular death rates in recent years. We don’t know for sure what factors are causative, but we can assume that improved and more aggressive screening and treatment, as well as being more vigilant about the management of cardiovascular disease in our patients might play a role. This study represents an important step forward and potentially the dawn of a new era in cardiovascular disease management in patients with RA,” said lead investigator Dr. Elena Myasoedova of the Mayo Clinic in Rochester, Minn.

“Although the link between RA and cardiovascular disease is well established, the trends in recent years are not well characterized. We aimed to address this in our study,” she explained.

The database included adult patients older than 18 years diagnosed with incident RA during 2000-2007 and patients diagnosed with RA in the 1990s. RA diagnosis was based on 1997 ACR criteria.