Individuals with early onset (premature) coronary artery disease display impaired systemic microvascular endothelial function: studies using laser speckle contrast imaging

Abstract

Purpose: Laser speckle contrast imaging (LSCI) provides an innovative approach to the non-invasive evaluation of systemic microvascular endothelial function. In the present work, we assessed skin microvascular reactivity in individuals with early onset coronary artery disease (EOCAD, diagnosis at less than 45 years of age) using LSCI coupled to pharmacological and physiological stimuli. Methods: Skin microvascular blood flow was continuously monitored in the forearm using LSCI. Acetylcholine (ACh) dose-response curves were performed using an iontophoresis micropharmacology system and post-occlusive reactive hyperemia (PORH) was analyzed after a 3-minute occlusion of blood flow to the forearm. Measurements of microvascular skin blood flow in arbitrary perfusion units (APU) were divided by mean arterial pressure to give cutaneous vascular conductance (CVC) in APU/mm Hg. The results were presented as mean ± SEM and were analyzed using two-tailed unpaired Student's t tests. Results: Fifty-eight patients with EOCAD aged 45±0.4 years (34 men) and 25 healthy age- and sex-matched individuals were included in the study. ACh- and PORH-mediated vasodilation was significantly reduced in EOCAD individuals. Area under the curve of ACh-induced vasodilation was of 6445±842 and 3975±540 APU/sec in controls vs. EOCAD, respectively; p=0.0087; figure 1). Increase in CVC resulting from PORH-induced vasodilation was of 0.46±0.03 and 0.38±0.02 APU/mmHg in controls vs. EOCAD, respectively; p=0.0182; figure 1). ![Figure][1] Conclusions: LSCI identifies systemic microvascular endothelial-dysfunction in individuals presenting with EOCAD and thus could be used as an early peripheral marker of the atherothrombotic disease. [1]: pending:yes