FORWARD WAVE AND ITS IMPACT ON AUGMENTATION INDEX: DO GENDER DIFFERENCES EXIST?

Abstract

Objective: Some studies have found that women have markedly higher aortic augmentation index (Aix) than men. Traditionally, this difference has been attributed to the early return of the reflected wave because of shorter stature and increased aortic stiffness in women. However, augmentation pressure is also affected by the shape of the forward wave. We aimed to assess the impact of gender on the association between forward aortic wave time, pressure and Aix in hypertensive patients. Design and method: 30 men and 37 women with hypertension were enrolled. Central hemodynamic was assessed using applanation tonometry method (SphygmoCor-Australia). We estimated central systolic and diastolic pressure, Aix, Aix adjusted by heart rate (Aix@75), pulse wave velocity (PWV), forward wave pressure (FWP), ejection duration (ED), time to peak forward wave (T1), time to peak systolic wave (T2) and reflected wave foot time (Tr). Results: Men and women had similar median of age (64 vs 66, p = 0.34), heart rate (77 vs 78, p = 0.40), peripheral systolic (133 vs 130mmHg, p = 0.32) and diastolic (80 vs 77mmHg, p = 0.16) pressure. Despite similar central systolic (119 vs 117mmHg, p = 0.47), diastolic (81 vs 78mmHg, p = 0.19) pressure and PWV (9.9 vs 9.4m/s, p = 0.79), women had higher Aix (33 vs 23%, p < 0.001), and Aix@75 (34 vs 26%; p < 0.001). Men and women had similar T2 and FWP, but Tr was higher in men (134 vs 130ms; p = 0.04), whereas ED (301 vs 314ms) and T1 (105 vs 109ms) – in women (p < 0.05). Tr minus T1 was higher in men (30 vs 22ms; p = 0.014). In a multivariate regression analysis in men Aix@75 was significantly associated with PWV (beta = 0.75, p = 0.005), whereas in women – with T1 (beta = 0.32, p = 0.04) and Tr (beta = 0.42, p = 0.009). Conclusions: As according to previous reports, women had higher Aix and Aix@75 and shorter time to backward wave return. However, we also found that men and women had different ejection patterns and women had higher forward wave peak time, that was significantly related to Aix@75 only in them. It may indicate that shape and time of the forward wave may also contribute to higher Aix in women compared to men.