Effectiveness of exhaled nitric oxide for the prediction of non-invasive left atrial pressure in older people: a cross-sectional cohort study

Abstract

BackgroundDuring left-sided heart failure (HF), left atrial and pulmonary venous pressure increase, which may lead to pulmonary congestion. Previous cohort studies, examining participants with symptomatic HF or rheumatic heart disease, suggest a relationship between increased left atrial pressure (LAP) and fractional exhaled nitric oxide (FeNO).AimTo examine the strength of association between FeNO and echocardiographic assessment of LAP by the E/e’ ratio, to determine if FeNO could be used to identify those with elevated LAP.Design & settingThis cross-sectional cohort study examined a subset of the OxVALVE cohort aged ≥65 years. Data collection was undertaken in primary care practices in central England.MethodEach participant underwent a focused cardiovascular history and clinical examination. Standard transthoracic echocardiographic (TTE) assessment was performed on all participants, with the E/e’ ratio calculated to obtain a validated surrogate of LAP. FeNO was measured in 227 participants.ResultsFeNO was higher in males compared with females and no different in participants with asthma, chronic obstructive pulmonary disease (COPD), or those using inhaled steroids. Participants with a high E/e’ (>14) were older, with a higher proportion of females than males. There was no relationship between E/e’ and FeNO, either when measured as a continuous variable or in the group with high E/e’.ConclusionFeNO was not found to be an accurate predictor of elevated LAP in a primary care setting.