Abstract 1073: Novel Markers of Left Ventricular Hypertrophy in African Americans With Hypertension
Background: African Americans with hypertension are prone to develop left ventricular hypertrophy (LVH), but the underlying mechanisms are not well-defined. Activation of multiple biological pathways within the myocardium is implicated in the pathogenesis of LVH in hypertension.
Methods: We investigated the associations of 46 markers representing inflammatory, neurohormonal, extracellular matrix remodeling, lipoprotein metabolism, and hemostasis pathways with the presence of LVH in 1034 African Americans (65±9 y, 72% women) with hypertension. Markers were measured in plasma or serum using several assays platforms. Left ventricular mass was measured by 2-D echocardiography and indexed by height2.7 (LVMi). LVH was defined as LVMi≥51 g/m2.7. The association of each marker with LVH was tested in separate multivariable logistic regression models, adjusting for conventional risk factors and medication use.
Results: Of the 46 markers, higher levels of N-terminal pro-beta natriuretic peptide (NT-proBNP) (P <0.0001), midregional pro-atrial natriuretic peptide (MR-proANP) (P <0.0001), vascular cellular adhesion molecule-1 (P=0.032), tissue inhibitor of metalloproteinase-1 (P=0.022), and osteopontin (P=0.020), and lower levels of apolipoprotein B (P=0.012), leptin (P=0.017), factor II (P =0.0001), and factor VIII activity (P<0.039) were each associated with LVH after adjusting for age, sex, BMI, systolic BP, total and HDL cholesterol, smoking, diabetes, history of myocardial infarction/stroke, GFR, and medication (BP-lowering, aspirin, statin, and estrogen) use. After further adjustment for multiple testing, using Bonferroni correction, only NT-proBNP (β±SE=0.64±0.14; P <0.001), MR-proANP (β±SE=0.68±0.20; P <0.001), and factor II activity (β±SE=−1.54±0.40; P <0.001) remained significantly associated with LVH. The c-statistic values for multivariable models that included NT-proBNP, MR-proANP, and factor II activity were 0.78, 0.76, and 0.76 respectively (versus 0.74 when only conventional risk factors included in the model).
Conclusion: In a large sample of African Americans with hypertension, a multimarker approach identified NT-proBNP, MR-proANP, and factor II activity as significant independent predictors of LVH.