Muscle VO2 and forearm blood flow repeatability during venous and arterial occlusions in healthy and coronary heart disease subjects

Abstract

This study aims were: 1) to assess forearm blood flow (FBF) and muscle oxygen consumption (mVO2) repeatability assessed with near-infra red spectroscopy (NIRS) during venous occlusions (VO) in middle aged healthy subjects and patients with stable coronary heart disease (CHD), 2) to assess the agreement between mVO2 calculated from NIRS signals during VO and arterial occlusion (AO) in 18 middle aged healthy subjects and 12 patients with CHD. FBF and mVO2 were measured using NIRS during 2 successive VO (1-min duration), followed by a 5-min AO. Repeatability for FBF and mVO2 during VO was assessed with intra class correlation (ICC), coefficient of variation (CV %) and agreement between VO and AO mVO2 was assessed with a Bland and Altman analysis. FBF and mVO2 during VO were highly reproducible in healthy (FBF: ICC 0.73, CV% 9.75; mVO2: ICC 0.89, CV% 12.6) and CHD subjects (FBF: ICC 0.95, CV% 10.26; mVO2: ICC 0.98, CV% 7.92). VO and AO mVO2 were in agreement in healthy (mean bias: 0.002 mL O2.min-1.100g-1) and CHD subjects (mean bias: 0.014 mL O2.min-1.100g-1). FBF and mVO2 measured with NIRS during VO and/or AO are highly reproducible methods to assess microvascular function in healthy subjects and stable CHD patients.