STRICTER AMBULATORY BLOOD PRESSURE CONTROL IS POSSIBLE IN PATIENTS AFTER KIDNEY TRANSPLANTATION AND IS ASSOCIATED WITH REGRESSION OF LEFT VENTRICULAR HYPERTROPHY: POST HOC ANALYSIS

Objective: The recently published analysis of the 4C-T study demonstrated an association of stricter cumulative office blood pressure (BP) control with lower left ventricular mass (LVM) in children after kidney transplantation. The aim of our study was to investigate whether stricter control of ambulatory BP is also associated with improved LVMI and regression of left ventricular hypertrophy (LVH) in pediatric kidney transplant recipients. Design and method: A post-hoc analysis of nineteen patients (median age at baseline 9.7 years, range 3.3–15.1, median time after transplantation 4.3 years, range 1.0-13.1) from our previous ESCORT trial who had echocardiography performed at baseline (T0), 1 (T1), 2 (T2) and 3 (T3) years was performed. Cumulative 24-hour mean arterial pressure (MAP) Z-scores (CMAPz) were calculated according to 4C-T study (Sugianto et al. 2023). Left ventricular hypertrophy (LVH) was defined as LVMi>40 g/m^2.7 in girls >9 yrs of age and LVMi>45 g/m^2.7 in boys >9 yrs of age; in children <=9 yrs the LVH was defined as LVMi >95th percentile (Khoury et al 2009). Results: The median CMAPz decreased from a median +0.27 (IQR=-0.09 to +0.38) in the 1st year down to -0.06 (IQR=-0.26 to +0.32) in the 2nd year (p=0.02) and to +0.05 (IQR=-0.32 to 0.27) in the 3rd year (p=0.04) of follow-up. The prevalence (number) of children with LVH was 26% (5/19) at T0, 16% (3/19) at T1, 23% (3/13) at T2 and 0% (0/11) at T3 (trend in proportions p=0.06). All 5 children with elevated LVMi>0.9 at T0 decreased / normalized their LVMi at T3 (p=0.07), on contrary children without LVH at baseline did not significantly change their LVMi during follow-up. Conclusions: This first prospective interventional study demonstrated an association between stricter cumulative ambulatory MAP and regression of LVH in patients after kidney transplantation. Our data suggest that aiming stricter ambulatory BP can improve the often unfavourable cardiac phenotype in these patients. However, randomized control trial is required to confirm our findings.