ABSTRACT
AIM: The aim of this study was to evaluate the effect of insulin-like growth factor 1 (IGF1) and transforming growth factor beta-1 (TGFbeta-1) on collagen turnover, left ventricular (LV) hypertrophy and on passive diastolic function of the LV in hypertrophic cardiomyopathy (HCM). METHODS: This study group comprised 34 patients with non-dilated HCM. Procollagen I amino-terminal propeptide (PINP) and collagen I carboxy-terminal telopeptide (ICTP) were measured by radioimmunoassay. Matrix metalloproteinase 9 (MMP 9), IGF1 and TGFalfa-1 were determined by enzyme-linked immunosorbent assay. The difference in duration between transmitral forward (A) and pulmonary venous retrograde (Ar) waves, was considered as an estimate of passive diastolic function; the ratio between the peak flow velocity at rapid filling at the mitral level (E) and E' measured by tissue Doppler was considered an estimate of active diastolic function. LV mass was measured and normalized to body surface area (LVMi) by cardiac magnetic resonance imaging. RESULTS: LVMi correlates to E/E' (r=0.597, P=0.019 ) and is inversely related to A-Ar (r=0.453, P=0.015). TGFbeta-1 is directly related to active MMP 9 (r=0.439, P=0.012 ). IGF1 is directly related to PICP-ICTP (r=0.347, P=0.501), that expresses the balance between collagen I synthesis and its degradation. CONCLUSION: The study demonstrated that in HCM, LVMi influences active and passive diastolic dysfunction and that IGF1 stimulates collagen synthesis and TGFbeta-1 is related to LV hypertrophy.
Subject(s)
Cardiomyopathy, Hypertrophic/diagnosis , Cardiomyopathy, Hypertrophic/metabolism , Collagen/metabolism , Hypertrophy, Left Ventricular/diagnosis , Hypertrophy, Left Ventricular/metabolism , Insulin-Like Growth Factor I/metabolism , Transforming Growth Factor beta1/metabolism , Adult , Algorithms , Biomarkers/metabolism , Collagen Type I , Echocardiography, Doppler , Enzyme-Linked Immunosorbent Assay , Female , Humans , Magnetic Resonance Imaging , Male , Matrix Metalloproteinase 9/metabolism , Middle Aged , Myocardium/metabolism , Peptide Fragments/metabolism , Peptides , Procollagen/metabolism , Radioimmunoassay , Ventricular Dysfunction, Left/diagnosis , Ventricular Dysfunction, Left/metabolismABSTRACT
AIM: The aim of this study was to assess the relationship between echocardiographic indexes of left ventricular (LV) hypertrophy with LV mass (LVM) obtained at cardiac magnetic resonance (CMR) in a population of patients with hypertrophic cardiomiopathy (HCM). METHODS: Thirty-nine patients with HCM underwent echocardiography and CMR. By echocardiography maximal wall thickness (MWT), Spirito' and Maron's hypertrophy index and the Wigle's score were obtained. Absolute LVM was measured through CMR and indexed to body surface area (LVMi). Data were analysed using linear regression analysis. RESULTS: In 31% of patients there was an incomplete echocardiographic LV anatomic characterization. However, there was a good correlation between MWT measured at echocardiography and at CMR (P<0.001; r=0.755). Overall echocardiographic indexes of LV hypertrophy correlate with either LVM and LVMi: MWT (P=0.008, r=0.420 and P=0.003, r=0.467, respectively); Spirito' and Maron's hypertrophy index (P=0.003, r=0.551 and P=0.001, r=0.606, respectively) and Wigle's score (P=0.004, r=0.522 and P=0.004, r=0.522, respectively). CONCLUSION: In our HCM population, although a complete anatomic LV anatomic characterization was not obtained by echocardiography in all patients, echocardiographic hypertrophic indexes showed a good correlation with LVM obtained by CMR.
