Pseudoxanthoma elasticum is associated with cardiocirculatory inefficiency

Pseudoxanthoma elasticum (PXE) is a rare, genetic, metabolic disease characterized by dystrophic calcification of elastic fibres in the skin, retina and vascular wall. Data on cardiac involvement are inconsistent. Hence, we aimed to evaluate cardiorespiratory response to incremental cardiopulmonary exercise testing (CPET) in PXE. A total of 30 PXE patients (54.0 ± 11.2 years, 40.0% male) and 15 matched controls underwent symptom-limited incremental CPET. PXE patients presented an impaired peak work rate as compared to controls (84.2 ± 16.0% vs. 94.7 ± 10.4%, p = 0.03) that was accompanied by a lower peak oxygen uptake (in % predicted and mL/min/kg), reduced increments in oxygen uptake per increments of work rate (ΔV´O2/ΔWR, 8.4 ± 3.0 mL/min/W vs. 11.3 ± 4.9 mL/min/W, p = 0.02), lower peak oxygen pulse (78.0 ± 12.3% vs. 90.6 ± 19.6%, p = 0.01) and reduced minute ventilation at peak exercise (V´E, 66.2 ± 16.8% vs. 82.9 ± 25.2%, p = 0.02). To summarize, we presently observed impairment in mainly cardiocirculatory parameters, whilst no substantial ventilatory limitation was detected. The potential implications of this finding for PXE management warrant further study.