Relationship of natriuretic peptide and transthoracic echocardiographic findings in 135 subjects with muscular dystrophy

Abstract

<h2>Abstract</h2><h3>Purpose</h3> To examine the usefulness of plasma atrial (ANP) and brain natriuretic peptide (BNP) levels and transthoracic echocardiogram (TTE) findings in predicting left ventricular (LV) dysfunction in muscular dystrophies (MD). <h3>Materials and methods</h3> 135 MD subjects (83 Duchenne MD (DMD), all males, mean age 22±7years, 20 Becker MD (BMD), all males, 45±16years, 21 limb-girdle MD (LGMD), 14 males, 52±13years, and 11 facioscapulohumeral MD (FSHD), all males, 58±13years) underwent TTE and measurement of BNP and ANP. <h3>Results</h3> In DMD, TTE revealed asynergy of the LV posterior-wall (72%), interventricular septum (IVS) (29%) and LV apex-wall (24%); in BMD subjects: TTE revealed asynergy of LV posterior-wall (50%) and IVS (25%); in LGMD and FSHD subjects: TTE revealed asynergy of LV posterior-wall (33 and 27%, respectively). LV end-diastolic (LVDdI) and end-systolic diameter index (LVDsI) were significantly larger in DMD than FSHD, and LV ejection fraction (LVEF) was significantly lower in DMD than LGMD and FSHD. In DMD, when LVEF was >=35%, BNP and ANP levels remained low, but when LVEF<35%, BNP and ANP levels showed steep increase. Relationship between LVEF and BNP or ANP levels was curvilinear (<i>R</i>²=0.69 and 0.55, respectively, <i>p</i><0.001) using following equation: BNP=673491×EF^−2.897, ANP=5716.6×EF^−1.422, respectively. When LVDdI>=40mm/m² or LVDsI>=35mm/m², LVEF<=35%, plasma BNP and ANP levels increased steeply and the relationship between LVDdI, LVDsI, or LVEF and plasma BNP or ANP levels was curvilinear. <h3>Conclusion</h3> In DMD, LVEF was significantly lower, asynergy of LV posterior-wall was more frequent and BNP and ANP levels were dramatically higher when LVDdI>=40mm/m², LVDsI>=35mm/m² or LVEF<35%.