ARTHRITIS PATIENTS HAVE 40% HIGHER RISK OF CVD DEATH

Arthritis Patients Remain at 50% Higher Risk of CVD Death

December 11, 2008 — A new meta-analysis has shown that patients with rheumatoid arthritis (RA) have a 50% higher risk of death from cardiovascular disease (CVD) than does the general public and that the improvement in CVD mortality seen over time in the wider population has not been mirrored in arthritis sufferers [1]. Dr J Antonio Aviña-Zubieta (University of British Columbia and Arthritis Research Center of Canada, Vancouver) and colleagues report their findings in the December 15, 2008, issue of Arthritis Care & Research.

"Previously, not all studies have consistently found this increased risk," Aviña-Zubieta told heartwire. "We firmly establish that CVD is increased in RA. And it's evident from our study that the argument about the extent of increased risk that has gone on in the past is mainly due to study design," he added.

"We still need to close the gap between CVD death in RA patients and the general population," he stresses. "The rheumatology community, as well as those treating patients with RA, needs to know that this gap still exists and needs to be tackled."

Almost 60% increased mortality risk from MI, 50% increased risk from stroke

In their meta-analysis, Aviña-Zubieta and colleagues searched a number of databases to July 2005 and included 24 observational studies comprising 111,758 patients with 22,927 cardiovascular events.

Overall, there was a 50% increased risk of CVD death in patients with RA. When looking at cause-specific deaths, patients with RA had a 59% increased risk of dying from ischemic heart disease (myocardial infarction [MI]) compared with the general population and a 52% increased risk of death due to stroke.

"Our findings show that the estimated risk varies depending on study design," Aviña-Zubieta explained. "Patients seen in community-based settings have a lower risk when compared with hospital-based clinics (35% vs 53%, respectively). The explanation for these differences in risk among studies is duration of follow-up. Studies that have more than 10 years of follow-up had the highest risk vs those with less than 10 years."

And importantly, he adds, "Changes in treatment strategies over time have not shown improvement in CVD mortality among RA patients — there is a similar risk between patients enrolled before 1987 and after 1987.

"This is very relevant, since it seems that the improvement in CVD mortality that has been demonstrated in the general population seems not to occur in RA patients."

He points out, however, that different RA classification criteria between these two periods could also partly explain this lack of improvement.

Studies of mortality with biologic therapy in RA needed

The researchers also note that the majority of studies included in their meta-analysis enrolled patients before the widespread use of biologic therapies for RA; "therefore, the results obtained may not be generalizable to RA patients treated with biologics."

And recent evidence suggests that all-cause and cause-specific mortality are not greater than expected in RA patients treated with biologic therapy, they note.

"The benefit of newer therapies with biologics remains to be determined," says Aviña-Zubieta. "More studies specifically evaluating mortality in RA patients treated with biologics would be valuable. These studies are urgently needed."

Other ongoing research is evaluating the impact that different treatments for RA have on CVD deaths at the population level, he says, and examining whether the increased mortality is due to increased fatality rate, increased number of events, or both.