Altered Blood Vessel Responses in the Eye and Finger in Coronary Artery Disease

Abstract

Cardiac function, such as heart rate variability, is abnormal in coronary artery disease, but its relation with the function of ocular and nail-fold blood vessels is unknown. The hypothesis was that there is abnormal retinal and peripheral microvascular endothelial function compared with large blood vessel and cardiac function. Twenty-four patients with coronary artery disease (CAD) and 30 healthy, age- and sex-matched control subjects were enrolled in the study. Peripheral microcirculatory function was measured with continuous retinal vessel diameter assessment and nail-fold capillaroscopy. Systemic vascular function was evaluated by 24-hour blood pressure, arterial stiffness, low (LF)- and high (HF)-frequency heart rate variability, ECG monitoring, and the plasma markers von Willebrand factor (vWf) and soluble E selectin. Peripheral nail-fold capillary (P = 0.009) and retinal vessel (average baseline corrected flicker response [BFR]; P = 0.034) responses and reaction time in response to flicker (P = 0.016) were significantly different in patients compared with controls. Furthermore, patients demonstrated higher arterial stiffness (P = 0.005), LF and HF heart rate variability (P = 0.004, P = 0.006), and vWf level (P = 0.044), but there was no difference in soluble E selectin level (P = 0.278). In the CAD patients, LF and HF heart rate variability both correlated with average BFR (r = 0.58, P = 0.004; r = -0.6, P = 0.003, respectively). There was no such relationship in the healthy controls. Microcirculatory abnormalities of the retina and nail-fold vessels are present in CAD. The two indices of heart rate variability correlated with an index of ocular vessel responses. The latter may be a surrogate marker of abnormal heart rate variability in CAD.