Microvascular endothelial dysfunction in heart failure patients: An indication for exercise treatment?

Endothelial dysfunction represents a diagnostic marker to differentiate disease severity in chronic heart failure (CHF) patients. Retinal vessel phenotyping was applied in CHF patients as it has been acknowledged as a sensitive diagnostic tool to quantify microvascular health and overall cardiovascular risk.; The central retinal arteriolar (CRAE) and venular diameter equivalents (CRVE) as well as the retinal microvascular function, quantified by arteriolar (aFID) and venular flicker-light induced dilatation (vFID), were analyzed in 26 CHF patients. These data were compared with 26 age- and sex-matched healthy peers. The effects of an exercise intervention on retinal microvascular health in one CHF patient were investigated to demonstrate potentially beneficial effects of exercise treatment in a case report format as proof of concept.; CHF patients showed narrower CRAE (170 ± 16 μm vs. 176 ± 16 μm, p = 0.237) and wider CRVE (217 ± 20 μm vs. 210 ± 17 μm, p = 0.152), resulting in a significantly lower arteriolar-to-venular diameter ratio (AVR, 0.79 ± 0.07 vs. 0.84 ± 0.06, p = 0.004) compared to controls. More strikingly, CHF patients showed significantly lower mean aFID (1.24 ± 1.14% vs. 3.78 ± 1.85%, p < 0.001) and vFID (2.89 ± 1.33% vs. 3.88 ± 1.83%, p = 0.033). Twelve weeks of exercise therapy induced wider CRAE (143 ± 1.0 μm vs. 153 ± 0.9 μm), narrower CRVE (183 ± 3.1 μm vs. 180 ± 2.4 μm) and improved aFID (0.67% vs. 1.25%) in a male 78 years old CHF patient.; aFID is a sensitive diagnostic tool to quantify microvascular impairments in CHF patients. Exercise treatment in CHF patients has high potential to improve retinal microvascular health as a marker for vascular regeneration and overall risk reduction, which warrants further examination by randomized controlled trials.