Background Cardiac involvement among patients with rheumatoid arthritis (RA) is common, potentially life-threatening, but often underdiagnosed at presymptomatic stages. Subendocardial viability ratio (SEVR) reflects microvascular coronary perfusion, as it correlates with the ratio of subepicardial to subendocardial blood flow, that can be non-invasively estimated by applanation tonometry. Although it has been studied as a surrogate measure of myocardial perfusion in high-cardiovascular risk populations, it remains unclear whether it is affected in RA patients.
Objectives The purpose of the study was to compare SEVR between RA patients and healthy controls. We additionally sought predictors of SEVR in RA among a wide range of disease-related parameters, hemodynamic factors, and markers of atherosclerosis, arteriosclerosis, and endothelial dysfunction.
Methods Consecutive patients with RA and healthy, nontreated volunteers were recruited. SEVR was estimated from applanation tonometry with the Sphygmocor device (AtCor Medical, Sydney, Australia), which was also used to evaluate arterial stiffness (aortic index, AIx; pulse wave velocity, PWV). In the RA group, carotid atherosclerosis was additionally evaluated by ultrasound (carotid intima-media thickness, cIMT); cardiac and hemodynamic parameters by impedance cardiography, and endothelial dysfunction by measurement of asymmetric dimethylarginine (ADMA) in serum samples.
Results A total of 122 participants, 91 RA patients and 31 controls, were studied. SEVR was significantly lower among RA patients compared to controls (141.4±21.9 vs 153.1±18.7%, p=0.005), and the same was observed when the subgroup of RA patients without cardiovascular comorbidities (n=29) was studied separately (139.7±21.7 vs 153.1±18.7%, p=0.013). In the univariate analysis, SEVR significantly correlated with cardiac and hemodynamic parameters, but not with PWV, AIx, cIMT, ADMA, or disease-related parameters. In the linear regression analysis accounting for sex, statin use, markers of atherosclerosis, cardiac, and hemodynamic parameters, female gender (p=0.007), blood pressure (p=0.028), heart rate (p=0.025), cholesterol levels (p=0.008), cardiac index (p<0.001), and left ventricular ejection time (p=0.004) were identified as independent predictors of SEVR among patients with RA.
Conclusions Patients with RA exhibit lower values of SEVR compared to healthy individuals, suggesting a disturbed balance between oxygen supply and demand that might provide an additional pathophysiological link for the increased cardiovascular burden in RA. Cardiac and hemodynamic parameters, rather than markers of atherosclerosis, arteriosclerosis, and endothelial dysfunction, may be useful as predictors of impaired myocardial perfusion in RA.
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Disclosure of Interest None declared