BOSTON, Mass–The relative risk of cardiovascular (CV) events in rheumatoid arthritis (RA) patients is highest among young patients and those without a history of prior events, according to new research released early online in the Annals of the Rheumatic Diseases.¹  Older RA patients still have the highest absolute risk, but RA did not increase CV risk in those who had already suffered a CV event at the time of RA diagnosis.

"Both young and old patients with RA are at an increased risk, [and] CV disease (CVD) risk factors need careful monitoring and treatment, including hyperlipidemia, hypertension, and diabetes," lead researcher Daniel H. Solomon, MD, MPH, an associate physician at Brigham and Women's Hospital in Boston, Massachusetts, told CIAOMed. "As well, physicians should carry a high index of suspicion for CVD and work-up patients with possible heart disease."

Dr. Solomon explained that although substantial prior literature linked RA and CVD, this study provides clinically useful information because it characterizes the level of risk among a variety of subgroups with RA. "This knowledge is critical for beginning to decide which patients with RA should be considered for interventions," he said.

The new cohort study included all residents of British Columbia aged 18 years or older between 1999 and 2003. Researchers compared 25,385 subjects diagnosed with RA during the study period with an RA-free cohort matched by age, gender, and start of follow-up. The primary composite endpoint was hospital admission for either myocardial infarction (MI) or stroke, or death from CVD.

During the 5-year study period, 375 patients with RA had a hospital admission for MI, 363 were hospitalized for a stroke, 437 died from CV causes, and 1042 had one of these outcomes. Overall, the rate of CVD death was increased by 30% among RA patients. Subjects with RA were 1.6 times as likely as non-RA subjects to have a CVD event, and the rate difference was 5.7 per 1000 person- years, Solomon et al report.

The rate ratio was 3.3 in persons 18–39 years of age vs 1.6 in those 75 years and older. The rate difference increased from 1.2 per 1000 person-years in the youngest age group to 19.7 per 1000 person-years in those 75 years and over. Among subjects with a prior CVD event, the rate ratios and rate differences were not elevated in RA, the study showed.

"Relative risk is highest among younger RA patients since they have fewer typical CVD risk factors," Dr. Solomon said,  "Thus, RA presents a unique risk among young patients [and] as a unique risk factor for CVD, it confers a high relative risk," Dr. Solomon said. Among older patients, RA is less influential than other known risk factors, the study authors conclude.

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