Myocardial ischaemia without obstructive coronary artery disease in rheumatoid arthritis: hypothesis-generating insights from a cross-sectional study.

OBJECTIVE: RA is associated with increased cardiovascular events, reportedly to equal diabetes mellitus (DM). The presence of myocardial ischaemia was assessed in asymptomatic high-risk RA patients and compared with patients with DM and a healthy control group.
METHODS: Eighteen consecutive non-diabetic RA patients without known cardiovascular disease who developed a new carotid atheromatic plaque during the last 3 years were matched 1:1 for traditional cardiovascular risk factors with asymptomatic type 2 DM patients and 1:2 with asymptomatic non-RA, non-DM control subjects. After dobutamine stress contrast echocardiography with wall-motion and perfusion evaluation, coronary angiography was performed in those with positive stress tests.
RESULTS: Ischaemia by echocardiography was found in 67% of RA patients; this was significantly higher than controls (31%, P = 0.019) but comparable to those with DM (78%, P = 0.71). Angiography performed in eight consenting RA patients was normal in four, revealed non-flow-limiting coronary atheromatic lesions in two and significant lesions in two patients. RA patients with ischaemia had CRP serum levels significantly higher by six-fold compared with those with normal stress echocardiography.
CONCLUSION: Asymptomatic RA patients may display myocardial ischaemia at similar levels to DM patients but with low prevalence of obstructive coronary artery disease. Microvascular abnormalities associated with increased inflammatory response may account for these findings. Their exact nature and significance require further evaluation.