Plasma myeloperoxidase and echocardiographic markers of impaired diastolic function in healthy individuals

BACKGROUND: Myeloperoxidase (MPO), a neutrophil-derived enzyme, is associated with oxidative stress and inflammation, which contribute to the pathophysiology of heart failure with preserved ejection fraction (HFpEF). Bioactive MPO causes vascular dysfunction and accumulation of serum uric acid (SUA). We investigated the association of plasma MPO and SUA with echocardiographic variables in a populational setting. METHODS: This was a cross-sectional analysis of the fourth visit of the STANISLAS cohort (N=1677 participants, age 49±14 years, 48% male), a population of initially healthy individuals. Participants were divided into four groups according to median plasma MPO and SUA levels. Adjusted linear regression models were used to assess the relationship of plasma MPO and SUA with echocardiographic markers. RESULTS: Participants with high MPO and high SUA were older, had more diabetes, a higher body mass index, lower estimated glomerular filtration rate and higher systolic blood pressure. In multivariable regression analyses, compared with patients with low MPO and low SUA, they had decreased left atrial reservoir strain (mean±SE=-1.43±0.62, p=0.022), decreased mitral annular e' velocity (mean±SE=-0.60±0.16, p<0.001) and more impaired left ventricular systolic global longitudinal strain (mean±SE=0.50±0.23, p=0.029). In contrast, high MPO with low SUA was not associated with impaired diastolic function. CONCLUSIONS: In a population setting, high MPO and SUA, indicative of high bioactive MPO, were associated with early markers of diastolic dysfunction, suggesting a potential role of the MPO pathway in the early development of HFpEF.