4D.03: INTRAFAMILIAL AGGREGATION AND HERITABILITY OF AORTIC REFLECTED (BACKWARD) WAVES DERIVED FROM WAVE-SEPARATION ANALYSIS. (June 2015)

• Record Type: Journal Article
• Authors: Woodiwiss, A.; Djami-Tchatchou, A.; Raymond, A.; Booysen, H.; Hodson, B.; Libhaber, E.; Sareli, P.; Norton, G.
• Is Part Of: Journal of hypertension. Volume 33(2015)Supplement 1
• Publication Date: 2015-06
• Subjects: Hypertension -- Periodicals; Hypertension -- Periodicals; 616.132005
• DOI: 10.1097/01.hjh.0000467507.06084.f1
• Languages: English
• ISSNs: 1473-5598

Abstract

Abstract : Objective: Although aortic augmentation index (AIx) and pressure (Pa) are inherited, AIx and Pa are poor measures of reflected (backward) wave function. As wave reflection predicts outcomes beyond brachial BP, we aimed to determine the intra-familial aggregation and heritability of indices of aortic wave reflection derived from wave separation analysis (reflected [backward] wave index [RI] and pressure [Pb]) and compare these with the intra-familial aggregation and heritability of AIx and Pa. Design and method: Aortic Pb, RI, Pa and AIx were determined using radial applanation tonometry and SphygmoCor software in 1152 participants of 315 families (111 father-mother pairs, 705 parent-child pairs and 301 sibling-sibling pairs) with 24 families including three generations from an urban developing community of black African ancestry. Aortic Pb was determined using wave separation analysis where the aortic forward and backward waves were separated using a triangular aortic flow wave. Heritability estimates (h2) were determined from S.A.G.E software. Results: With adjustments for age, sex, pulse rate, mean arterial pressure, body weight, body height, regular smoking, regular alcohol intake and diabetes mellitus or an HbA1c > 6.1%, significant correlations were noted between parent-child pairs for Pb, RI and Pa (p < 0.05 for all), but not for AIx (p = 0.90) and between sibling-sibling pairs for Pb and Pa (p < 0.05), but not for RI (p = 0.06) or AIx (p = 0.14). No correlations for indices of wave reflection were noted between fathers and mothers (p > 0.57). After the aforementioned adjustments, Pb (h2 = 0.24 ± 0.07), RI (h2 = 0.26 ± 0.07) and Pa (h2 = 0.23 ± 0.07)(p < 0.001 for all) but not AIx (h2 = 0.10 ± 0.07, p = 0.07) showed significant heritability. Intra-familial correlations and heritability estimates for Pa remained significant despite further adjustments for either Pb (h2 = 0.13 ± 0.06, p < 0.05) or RI (h2 = 0.14 ± 0.06, p < 0.05). The intra-familial aggregation and heritability of aortic pulse pressure was accounted for by both Pb and forward wave pressures. Conclusions: Aortic reflected (backward) waves derived from wave separation analysis show intra-familial aggregation and heritability, but these effects are poorly characterized by measures of aortic pressure augmentation.