Impaired coronary microvascular and left ventricular diastolic functions in patients with ankylosing spondylitis

It has been shown that the patients with inflammatory rheumatic diseases such as systemic lupus erythematosus and rheumatoid arthritis have an increased risk of developing atherosclerosis. However, the association of ankylosing spondylitis (AS) to atherosclerosis and related diseases is still controversial. Accordingly, we investigated coronary flow reserve (CFR) and left ventricular (LV) diastolic function in patients with AS using transthoracic Doppler echocardiography.

CFR and LV diastolic function were studied in 40 patients with AS (38.9+/-10.2 years, 26 males) and 35 healthy volunteers (37.5+/-6.4 years, 23 males). Coronary diastolic peak flow velocities (DPFV) were measured at baseline and after dipyridamole infusion. CFR was calculated as the ratio of hyperemic to baseline DPFV. LV diastolic function was assessed by both standard and tissue Doppler imaging.

Demographic features and coronary risk factors except diastolic blood pressure were similar between the groups. CFR were significantly lower in the AS group than in the control group (2.20+/-0.46 versus 3.02+/-1.50, P<0.0001). Reflecting LV diastolic function mitral A-wave and E/A ratio were borderline significant, and mitral E-wave deceleration time and isovolumic relaxation time were significantly different between the groups. Serum hsCRP and TNF-alpha levels were significantly higher in the patients with AS, and hsCRP and TNF-alpha levels independently correlated with CFR.

These findings show that CFR reflecting coronary microvascular function and LV diastolic function are impaired in patients with AS, and severity of these impairments correlate well with hsCRP and TNF-alpha. These results suggest that impaired CFR may be an early manifestation of cardiac involvement in patients with AS.