Elevated level of N-terminal pro B-type natriuretic peptide is associated with myocardial fibrosis in hypertrophic cardiomyopathy patients with preserved ejection fraction

Abstract

Background: Myocardial fibrosis assessed by late gadolinium enhancement (LGE) on cardiovascular magnetic resonance (CMR) has been reported to be significantly correlated with cardiovascular outcomes in hypertrophic cardiomyopathy (HCM) patients. However, data regarding non-invasive markers for detecting myocardial fibrosis were inconsistent and, not systematically evaluated in HCM patients with preserved ejection fraction (EF).Methods: In this study, 86 HCM patients with preserved EF and 33 controls were enrolled. The left ventricular function, end-diastolic maximum wall thickness (MWT), global systolic strains and extent of LGE (% LGE) were assessed. The biochemical indices were also recorded before the CMR examination.Results: Serum high-sensitivity cardiac troponin I (hs-cTnI) and N-terminal pro b-type natriuretic peptide (Nt-proBNP) levels were elevated in LGE-positive patients compared with LGE-negative patients (p < 0.05 for all). The LGE-positive patients had lower global longitudinal (GLS) and circumferential (GCS) strains than the LGE-negative group and the healthy controls (p < 0.05 for all). The LGE% was independently associated with the Nt-proBNP levels (standardized β = 0.627, p < 0.001), beta-blocker treatment (standardized β = -0.372, p = 0.01), MWT (standardized β = 0.481, p = 0.001) and GCS (standardized β = 0.406, p = 0.013). In the receiver operating characteristic (ROC) curve analysis, the combined parameters of Nt-proBNP ≥ 108 pg/mL and MWT ≥ 17.3 mm had good diagnostic performance for LGE, with a specificity of 81.3% and sensitivity of 70.0%.Conclusions: This study suggests that Nt-proBNP may be a potential biomarker associated with LGE% and, combined with MWT, was useful in detecting myocardial fibrosis in HCM patients with preserved EF. Additionally, LV GCS may be a more sensitive indicator for reflecting the presence of myocardial fibrosis than GLS.