Imaging Technologies Hold Promise for CVD Risk Stratification in RA

Patients with rheumatoid arthritis (RA) are at greater risk for cardiovascular disease (CVD) than the general population. Indeed, patients with RA have 50% increased risk of dying of CVD.¹ This makes CVD risk stratification an imperative in patients with RA, but the CVD risk profile in RA is unique, and assessment is not well accommodated by conventional CVD risk algorithms. Furthermore, CVD risk algorithms for patients with RA have been flawed, either under- or overestimating risk. Development of accurate CVD risk algorithms in RA would naturally help optimize both RA and cardiovascular health in affected patients.

Efforts have been made to address the inaccuracies of CVD risk algorithms for patients with RA, but challenges to accuracy and validation persist. Enter a team of authors from the University of Leeds in the UK. The authors argue that the risk algorithms in hand may be more useful if paired with imaging technology.² They point out, in a review article published in Annals of the Rheumatic Diseases, that current cardiovascular imaging modalities can detect atherosclerotic disease as well as valvular abnormalities, left ventricular (LV) dysfunction, and cardiovascular inflammatory processes that are characteristic of RA pathology.²

The researchers propose that the ideal imaging technique for assessment of CVD risk in patients with RA would have high accuracy in predicting cardiovascular-associated mortality; the ability to detect early subclinical signs of atherosclerosis; allow for longitudinal evaluation of change in CVD; and detect the impact of CVD on a particular patient. More investigation into the utility of imaging technology for CVD risk stratification in patients with RA is needed, acknowledged the study investigators.

Imaging technologies of potential benefit include transcutaneous devices, ultrasound, computed tomography (CT), positron emission tomography (PET), and cardiovascular magnetic resonance (CMR). Each modality has benefits and limitations, which the team from the University of Leeds briefly discussed in its review article.

Transcutaneous devices, such as the SphygmoCor Arterial Waveform Analysis System (AtCor Medical, Itasca, IL) assess arterial stiffness via measurement of aortic pulse wave velocity and augmentation index. Ultrasound can assess carotid intima-media thickness and presence of atherosclerotic plaque. CT can be used to assess coronary artery calcium score — a direct measure of early atherosclerosis — or be used for CT coronary angiography (CTCA), which, although used to assess low to intermediate probability of significant coronary artery disease, could potentially be used for CVD risk assessment in patients with RA, said the research team.

PET myocardial perfusion imaging enables accurate measurement of LV volumes and assessment of myocardial blood flow, and CMR is a radiation-free modality for comprehensive assessment of myocardial and overall cardiovascular structure and function, including precise and reproducible quantitation of LV and right ventricular volumes, mass, and ejection fraction.

The main current limitation of these modalities is the how-to of optimal application to CVD risk stratification in patients with RA. For some of these modalities, such as CTCA, radiation exposure may be of concern. For others, such as PET and CMR, expense is a major limiting factor. In addition, CMR is contraindicated in patients with metallic implants or prostheses.

The researchers concluded by stressing that CVD risk stratification is crucial in patients with RA but that prognostic data for affected patients are limited. The team proposed that imaging technologies could potentially have significant utility in closing the gap; however, strong longitudinal data on CVD outcomes in RA are needed.

Summary & Clinical Applicability

CVD risk stratification is crucial in patients with RA, but conventional CVD risk stratification algorithms do not accommodate patients with RA at risk for CVD. Prognostic data for affected patients are limited. Risk stratification algorithms in this patient population could potentially be bolstered by use of imaging technologies; however, strong longitudinal data on CVD outcomes in RA are needed.

References

1. Aviña-Zubieta JA, Choi HK, Sadatsafavi M, et al. Risk of cardiovascular mortality in patients with rheumatoid arthritis: a meta-analysis of observational studies. Arthritis Rheum. 2008;59(12):1690-1697.
2. Fent GJ, Greenwood JP, Plein S, Buch MH. The role of non-invasive cardiovascular imaging in the assessment of cardiovascular risk in rheumatoid arthritis: where we are and where we need to be. Ann Rheum Dis. 2016 Nov 28. doi:10.1136/annrheumdis-2016-209744 [Epub ahead of print]

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