N-Terminal pro C-Type Natriuretic Peptide (NTproCNP) and myocardial function in ageing

Ageing-related alterations in cardiovascular structure and function are commonly associated with chronic inflammation. A potential blood-based biomarker indicative of a chronic inflammatory state is N-Terminal Pro C-Type Natriuretic Peptide (NTproCNP). We aim to investigate associations between NTproCNP and ageing-related impairments in cardiovascular function. Community-based participants underwent same-day assessment of cardiovascular function and circulating profiles of plasma NTproCNP. Associations between cardiovascular and biomarker profiles were studied in adjusted models including standard covariates. We studied 93 participants (mean age 73 ± 5.3 years, 36 women), of whom 55 (59%) had impaired myocardial relaxation (ratio of peak velocity flow in early diastole E (m/s) to peak velocity flow in late diastole by atrial contraction A (m/s) <0.84). Participants with impaired myocardial relaxation were also found to have lower peak early phase filling velocity (0.6 ± 0.1 vs 0.7 ± 0.1, p < 0.0001) and higher peak atrial phase filling velocity (0.9 ± 0.1 vs 0.7 ± 0.1, p < 0.0001). NTproCNP levelswere significantly lower among participants with impaired myocardial relaxation (16.4% vs 39.5% with NTproCNP ≥ 19, p = 0.012). After multivariable adjustments, NTproCNP was independently associated with impaired myocardial relaxation (OR 2.99, 95%CI 1.12-8.01, p = 0.029). Community elderly adults with myocardial ageing have lower NTproCNP levels compared to those with preserved myocardial function. Given that impaired myocardial relaxation probably represents early changes within the myocardium with ageing, NTproCNP may be useful as an 'upstream' biomarker useful for charting myocardial ageing.