RESUMO
Vitamin D seems to protect against cardiovascular disease, but the reported effects of vitamin D on patient outcomes in CKD are controversial. We conducted a prospective, double blind, randomized, placebo-controlled trial to determine whether oral activated vitamin D reduces left ventricular (LV) mass in patients with stages 3-5 CKD with LV hypertrophy. Subjects with echocardiographic criteria of LV hypertrophy were randomly assigned to receive either oral paricalcitol (1 µg) one time daily (n=30) or matching placebo (n=30) for 52 weeks. The primary end point was change in LV mass index over 52 weeks, which was measured by cardiac magnetic resonance imaging. Secondary end points included changes in LV volume, echocardiographic measures of systolic and diastolic function, biochemical parameters of mineral bone disease, and measures of renal function. Change in LV mass index did not differ significantly between groups (median [interquartile range], -2.59 [-6.13 to 0.32] g/m(2) with paricalcitol versus -4.85 [-9.89 to 1.10] g/m(2) with placebo). Changes in LV volume, ejection fraction, tissue Doppler-derived measures of early diastolic and systolic mitral annular velocities, and ratio of early mitral inflow velocity to early diastolic mitral annular velocity did not differ between the groups. However, paricalcitol treatment significantly reduced intact parathyroid hormone (P<0.001) and alkaline phosphatase (P=0.001) levels as well as the number of cardiovascular-related hospitalizations compared with placebo. In conclusion, 52 weeks of treatment with oral paricalcitol (1 µg one time daily) significantly improved secondary hyperparathyroidism but did not alter measures of LV structure and function in patients with severe CKD.
Assuntos
Ergocalciferóis/uso terapêutico , Hipertrofia Ventricular Esquerda/tratamento farmacológico , Hipertrofia Ventricular Esquerda/etiologia , Insuficiência Renal Crônica/complicações , Insuficiência Renal Crônica/tratamento farmacológico , Disfunção Ventricular Esquerda/tratamento farmacológico , Disfunção Ventricular Esquerda/etiologia , Idoso , Fosfatase Alcalina/sangue , Pressão Sanguínea/efeitos dos fármacos , Método Duplo-Cego , Ecocardiografia , Ergocalciferóis/efeitos adversos , Feminino , Humanos , Hipercalcemia/induzido quimicamente , Hipertrofia Ventricular Esquerda/patologia , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Hormônio Paratireóideo/sangue , Estudos Prospectivos , Insuficiência Renal Crônica/patologia , Disfunção Ventricular Esquerda/fisiopatologiaRESUMO
BACKGROUND: This study adopted a new multi-layer approach of measuring myocardial deformation by two-dimensional (2D) speckle tracking imaging to examine whether a transmural gradient exists in normal subjects and cardiac diseases. METHODS: Eighty patients were included with 20 in each group: (1) normal control; (2) acute coronary syndrome (ACS) with ejection fraction (EF) >45%; (3) right ventricular apical (RVA) pacing with EF>45%; (4) systolic heart failure (SHF) with EF<45%. Circumferential strain (ε-circum), torsion (Tor) and systolic dyssynchrony defined as the maximal difference in the time to peak circumferential strain were measured in the subendocardial and subepicardial myocardium layers (QLab 6.0, Philips). RESULTS: In all the 4 groups, a subendocardial to subepicardial gradient was present in both ε-circum (-20.7 ± 7.6 vs. -14.9 ± 5.6%, p<0.001) and Tor (12.0 ± 6.0 vs. 9.3 ± 4.7°, p<0.05), with higher values in the subendocardial layer. However, it was significantly narrowed for ε-circum (2.7 ± 1.2%) and Tor (0.8 ± 0.9°) in SHF patients (all p ≤ 0.001 vs. other groups). On the contrary, systolic dyssynchrony measured in the 2 layers showed no difference (264 ± 107 vs. 273 ± 110 ms, p = NS) and a homogenous distribution in ε-circum was observed from basal to apical planes (-17.0 ± 6.8 vs. -18.1 ± 7.4 vs. -18.1 ± 7.8%, all p = NS). CONCLUSIONS: A transmural gradient exists in circumferential strain and torsion, with higher values in the subendocardial layer. It might be reduced when systolic function is impaired. Therefore, the multi-layer approach of 2D speckle tracking imaging provides further information on assessment of myocardial diseases.