Cardiovascular Risk in RA: What Counts?

March 6, 2015

Patients with rheumatoid arthritis have double or triple the usual risk of cardiovascular disease. Guidelines give little advice about how to measure or reduce it. Can assessment tools be made more specific?

Barber CE, Smith A, Esdaile JM, et al., Best Practices for Cardiovascular Disease Prevention in Rheumatoid Arthritis: A Systematic Review of Guideline Recommendations and Quality Indicators. Arthritis Care & Research. 2015;67:169–179. Article first published online: 27 Jan 2015. doi: 10.1002/acr.22419

Arts EE, Popa CD, Den Broeder AA, et al., Prediction of cardiovascular risk in rheumatoid arthritis: performance of original and adapted SCORE algorithms.Ann Rheum Dis. 2015; Feb 17. doi: 10.1136/annrheumdis-2014-206879. [Epub ahead of print] 

Patients with rheumatoid arthritis (RA) have a 2- to 3-fold greater risk of cardiovascular disease (CVD) and CVD death than the population in general.

However, according to the two reviews above, although regular screening and risk assessment is recommended for these patients, rheumatologists are given scant specific guidance about what to measure, which thresholds are red flags, and how to reduce this risk in RA.

The first systematic review of CVD screening/prevention guidelines and quality indicators for CVD prevention among RA patients (Barber et al, above) reveals that only 5 of 10 RA guidelines recommend regular assessment of cardiovascular risk factors. And only 7 of 10 guidelines on CVD for the general public even mention RA as increasing CVD risk.

The European League Against Rheumatism (EULAR) 2010and British Society of Rheumatology (BSR) 2009 RA guidelines both recommended using a CV risk score, but only the EULAR guidelines suggest formal adjustment of the CV risk score for RA.

The BSR guidelines recommend screening and management of CV risk, basing treatment thresholds on general CV risk thresholds. Other RA guidelines suggest assessing and treating CVD risk factors (e.g., smoking, hypertension), but offer no risk calculator.

Quality indicator sets for CV risk assessment are mentioned in only three guidelines (American College of Rheumatology 2008, European Musculoskeletal Conditions Surveillance and Information Network 2014, and UK National Institute for Health and Care Excellence 2012). They recommend considering only glucocorticoid use, general comorbidities, and exercise levels.

There are no existing recommendations on CVD risk screening in RA, these authors conclude, no specific recommended thresholds for treatment of modifiable risk factors, and only "limited" recommendations about CVD in general in RA guidelines.

What's more, the performance of existing CVD risk calculators, such as the US Framingham Risk Score (FRS) and the European Systematic Coronary Risk Evaluation (SCORE) algorithm, which are based on traditional cardiovascular risk factors and  designed for a general population, is suboptimal in RA, according to authors Arts et al in the second article above.

Because they don’t take into account factors such as disease activity and inflammation that may impact CVD risk in RA, say these authors, standard risk tools may underestimate CVD risk in RA patients. So efforts to prevent cardiovascular comorbidity and mortality in RA patients based on these scores may also be insufficient.

After analyzing the performance of the FRS and SCORE models in RA, the researchers from Radboud University Medical Center in Nijmegen theorized that the tools might be adapted to include factors that apply to RA.

However, they find that even a European SCORE calculator modified for RA in this way performs poorly in predicting cardiovascular events.

The modified score included the following RA-specific indicators:

•   Rheumatoid factor (RF)
•   Anti-cyclic citrullinated peptide (Anti-CCP)
•   Disease activity in 28 joints (DAS28) score (cut-off >5.1)
•   C-reactive Protein (CRP)
•   Erythrocyte sedimentation rate (ESR)
•   Swollen joint count
•   Tender joint count
•   Patient Visual Analogue Sore (VAS) for global disease activity
•   Health Assessment Questionnaire (HAQ)

The team analyzed the predictive performance of SCORE and the adapted SCORE algorithms for CVD events (e.g., MI or angina), comparing the observed number of CVD events against the number of CVD events predicted by the SCORE algorithms in categories of predicted risk.

The adapted SCORE did not show a clear advantage in reclassifying patients with RA who develop CVD into more appropriate risk groups, the team found. Nor did it improve prediction of CVD events in the group as a whole.

Perhaps another study using a larger cohort and more or different indicators of inflammation might achieve better results, they suggest. But for the time being, measuring true cardiovascular risk in RA patients and taking appropriate steps to reduce it must remain poorly educated guesswork.