Al-Omari, Malik A.

Aortic stenosis (AS) requires repeat assessments to optimally time intervention. The utility of laboratory tests to complement clinical and hemodynamic assessments has not been established. We assessed clinical, echocardiographic, and laboratory data in 76 patients with AS or heart valve replacement (HVR), age 77 years, 37% women. Laboratory assessments included von Willebrand factor (VWF) antigen, activity, (Act/Ag, normal > 0.8), VWF multimer distribution (abnormal=loss of highest molecular weight multimers=Mult+), brain natriuretic peptide (BNP, abnormal > 155 pg/ml=BNP+), and platelet function analyzer 100 collagen-ADP closure time (PFA, normal < 121 seconds). Table: Coefficients of correlation, r, and F statistic. Chi-square, and probability. Correlation of BNP to mean gradient in patients with GFR>60 remained poor, r=0.29, while for PFA r = 0.65. Median (IQR) for PFA and BNP for mild, moderate, and severe AS and HVR are shown below. VWF multimers were abnormal in 3/14 mild AS, 6/14 moderate AS, 22/25 severe AS and 4/23 HVR patients. The severity of AS was most strongly associated with VWF multimer abnormality and prolonged PFA closure time, weakly with BNP, and not with VWF Act/Ag. Conclusion: Among various laboratory measures, PFA and VWF multimers are strongly associated with AS severity, and may merit assessment as complementary diagnostic and prognostic biomarkers in AS.

Left ventricular (LV) hypertrophy, a marker for adverse cardiovascular events, is more common in blacks than in non-Hispanic whites. Mechanisms leading to LV hypertrophy and mediating its clinical sequelae in blacks are not fully understood. We investigated the associations of 39 candidate biomarkers in distinct biological pathways with LV mass and geometry in blacks. Participants included 1193 blacks (63±9 years of age; 72% women; 78% hypertensive) belonging to hypertensive sibships. LV mass was measured by transthoracic echocardiography and indexed to height. 2.7 LV geometry was categorized as normal, concentric remodeling, concentric hypertrophy, and eccentric hypertrophy. Generalized estimating equations were used to assess associations of the 39 biomarkers with LV mass index after adjustment for age, sex, and conventional risk factors. After adjustment for potential confounders, log-transformed levels of the following biomarkers were independently associated with LV mass index: N-terminal pro-brain natriuretic peptide (β±SE=0.07±0.01 pg/mL; P <0.0001), mid-regional pro-atrial natriuretic peptide (β±SE=0.08±0.02 pmol/L; P <0.0001), mid-regional pro-adrenomedullin (β±SE=0.09±0.03 nmol/L; P =0.0006), C-terminal pro-endothelin (β± SE=0.05±0.02 pmol/L; P =0.0009), and osteoprotegerin (β±SE=0.07±0.02 pg/mL; P =0.0005) (β is for 1 log increase in biomarker level). The associations of these biomarkers with LV mass index were mainly due to their association with eccentric hypertrophy. Higher circulating levels of natriuretic peptides, adrenomedullin, endothelin, and osteoprotegerin were associated with increased LV mass index, providing insights into the pathophysiology of LV hypertrophy in blacks.