The Reverse Remodeling of the Aorta in Patients After Renal Transplantation - the Value of Aortic Stiffness Index: Prospective Echocardiographic Study

Background: Atherosclerosis is regarded as a combination of two major separate diseases: atherosis and sclerosis. Sclerotic component depends on deterioration of elastic properties of the aortic wall and is called aortic stiffness. The most valuable, non-invasive method of aortic stiffness assessment is echocardiography, which allows to calculate the aortic stiffness index (ASI). ASI is an independent predictor of all-cause and cardiovascular mortality in different groups of patients. The main aim of study was the assessment of the aortic reverse remodeling in patients with end-stage renal disease (ESRD) after renal transplantation (RT).

Methods: Study group involved 42 patients aged 43.3 ± 12.6 years, including 19 women aged 49.9 ± 10.9 years and 23 men aged 41.5 ± 12.91 years, who have undergone RT from non-related renal transplant donors, The study protocol has been consisted of 5 stages: 1 week after RT, 3 months after RT, 6 months after RT, 1 year after RT and 3 years after RT. The echocardiographic examination was performed and measurements of Ao, Ao were done. On the base of obtained parameters ASI, aortic distensibility (AD) and aortic strain (AS) were calculated according to adequate formulas.

Results: The improvement of indices characterizing the elastic properties of aorta were noted. These changes attained the statistically significant level only at the end of the observation. ASI just after RT was equal - 4.65 ± 1.58, three months after RT - 4.54 ± 1.49, six months after RT - 4.59 ± 1.61, one year after RT - 4.35 ± 1.21 and three years after RT - 3.35 ± 1.29, while AD reached respectively - 6.55 ± 3.76 cm/dyn10 just after RT, - 6.38 ± 3.42 cm/dyn10 three months after RT, - 6.53 ± 3.60 cm/dyn10 six months after RT, - 6.48 ± 2.79 cm/dyn10 one year after RT and - 8.03 ± 3.95 cm/dyn10 three years after RT. Noted AS values were equal - 6.61 ± 4.05%, just after RT, - 6.40 ± 3.58% three months after RT, - 6.56 ± 3.76%, six months after RT, - 6.45 ± 2.80% one year after RT, - 8.01 ± 3.97%. and three years after RT. The exact analysis of parameters concerning aortic function showed that to achieve ASI, AD and AS improvement, long time was needed, because the most significant changes of these indices were observed only between 1 year and 3 years after RT.

Conclusions: There is a relationship between renal transplantation and improvement of the aortic elastic properties. The recovery of the renal function allows to initiate the reparative processes leading to at least partial restitution of the structure and features of the aorta, which is called reverse remodelling. Improvement of aortic wall elastic properties after renal transplantation is a continuous and prolonged process.