Abstract 6133: Microvascular Dysfunction and Chronic Inflammation in Patients without Cardiovascular Risk Factors
Premature coronary atherosclerosis, which is actually seen as an active inflammatory process, is an established complication of systemic autoimmune diseases such as systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). We hypothesized that exposure to chronic inflammation, even in the absence of classical cardiovascular risk factors (CVRF), could result in coronary microvascular dysfunction (CMD), an early marker of coronary atherosclerosis. By means of positron emission tomography in combination with oxygen-15 labeled water, myocardial blood flow (MBF) was measured at rest and during iv adenosine infusion (140 μg/kg/min) in 13 SLE and 12 RA patients (mean [±SD] age 44±10 years) without CVRF. All patients underwent coronary angiography using multi-slice (64 slices) computed tomography and only those with none or trivial coronary artery disease (<30% luminal stenosis) were included. A group of 25 age- and gender-matched controls were also studied. There were no differences between patients and controls regarding body-mass index, blood pressure and lipid parameters. RA and SLE patients showed similar mean disease duration (16±11 and 11±7 years, respectively; p=0.12). Resting MBF was similar in patients and controls (1.25±0.27 vs 1.15±0.24 ml/min/g, p=0.15). However, during adenosine stress patients had lower MBF compared with controls (2.94±0.83 vs 4.11±0.84 ml/min/g, p<0.001). As result, coronary flow reserve (CFR; adenosine/resting MBF) was significantly reduced in patients (2.44±0.78) compared with controls (3.81±1.07; p<0.001). Seven patients showed ischemic electrocardiographic changes during adenosine and had a more severe reduction in CFR (1.76±0.81) and more years of disease (21±7 years) compared with those patients without ischemic changes (CFR 2.49±0.54; p=0.006; duration of disease 14±5 years; p=0.03). CFR was inversely correlated with years of disease (r=−0.65, p<0.001), but not with corticosteroid cumulative dose (r=0.20, p=0.39). Chronic inflammation in the absence of traditional CVRF is characterized by severe CMD. This may represent an early marker of disease which precedes and contributes to premature coronary artery disease in patients with RA and SLE.