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

PurposeTo 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).Materials and methods135 MD subjects (83 Duchenne MD (DMD), all males, mean age 22 ± 7 years, 20 Becker MD (BMD), all males, 45 ± 16 years, 21 limb-girdle MD (LGMD), 14 males, 52 ± 13 years, and 11 facioscapulohumeral MD (FSHD), all males, 58 ± 13 years) underwent TTE and measurement of BNP and ANP.ResultsIn 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 (R2 = 0.69 and 0.55, respectively, p < 0.001) using following equation: BNP = 673491×EF− 2.897, ANP = 5716.6 × EF− 1.422, respectively. When LVDdI > = 40 mm/m2 or LVDsI > = 35 mm/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.ConclusionIn DMD, LVEF was significantly lower, asynergy of LV posterior-wall was more frequent and BNP and ANP levels were dramatically higher when LVDdI > = 40 mm/m2, LVDsI > = 35 mm/m2 or LVEF < 35%.