#1202 Long-term evaluation of coronary calcifications in kidney transplanted patients: a single center follow up of 15 years
Authors: Alfieri Carlo , Perna Alessandro , Forzenigo Laura , Pisacreta Anna , Molinari Paolo , Regalia Anna , Castellano Giuseppe 
Published: May 2024

Abstract

Background
Patients with chronic kidney disease (CKD) have a relevant cardiovascular (CV) risk. Vascular calcification, particularly at coronary levels, have been related to the increased CV mortality. Few data are available on the long-term behavior of coronary artery calcifications (CAC) in kidney transplantation (KTx). In a previous paper (Alfieri C et al. Sci Rep. 2019 May 3;9(1):6869), our group explored the prevalence, the clinical and biochemical factors related with CAC and the factors implicated with CAC progression in a group of 64 KTx patients (KTXps) followed up for 5 years. Here we present the preliminary data about CAC follow up of the same population followed up for 15 years after KTx.

Methods
In 2007 we studied a total of 67 KTxps transplanted in our unit between 2007 and 2008. At the present time, 19 of them were lost from the follow up: 8 died, 4 because of major cardiovascular event (MACE), 11 KTxps had a graft loss and the other 20 did not adhere to the control. For this study, we evaluated 28 KTxps (M = 18; mean age 60 ± 9 yrs). Clinical parameters, blood and urinary analyses were recorded for 15 years, with particular attention for the year before CAC evaluation. For the statistical analysis the mean values of these evaluations were considered. At baseline and after 15 years from KTx, coronary TC for the evaluation of CAC using Agatson score was performed. According to the score obtained, patients were categorized in 4 groups both at baseline and at 15th year: 1) 0-10; 2) 10-100; 3) 100-400; 4) &gt;400. The progression of CAC was determined considering the modification in CAC category (Cat-Prog+T15) and using the formula proposed by Sevrukov (AJR, 2005 Dec;185(6):1546-53) (Prog+).

Results
At baseline and at 15 yrs after KTx, 46% and 18% of pts were in the 1st group, 14% and 25% in the 2nd, 29% and 18% in the 3rd and 11% and 39% in 4th, respectively. CAC at 15yrs were significantly higher than baseline (156 ± 50 vs 334 ± 71 p &lt; 0.0001). Both at baseline and after 15yrs CAC correlated directly with age (p = 0.0001; p = 0.01 resp.) and with each other (p &lt; 0.0001). In the 79% Cat-Prog+T15 was found, in the 10,7% of more than 1 class of CAC. Prog+ was discovered in the 71% of KTxps. They were characterized to have higher systolic blood pressure levels (P = 0.05, with no difference in specific therapy), lower mean Hb and Ca levels (p = 0.02; p = 0.07 resp). In a logistic model, mean Ca Levels resulted the only independent factor inversely related with CAC15prog+ (p = 0.04). During the 15 years of KTx a MACE was experienced by the 25% of KTxps, just older than the others. Apparently, no impact for CACs was found in MACE.

Conclusions
To the best of our knowledge, our study is the first one to evaluate CACs in the same cohort of KTxps for such a long time. According to the preliminary data obtained, the prevalence of CAC in KTxps is quite high, and is related to age. CAC worsening, after 15 years of KTX was observed in a consistent part of the cohort and was related to different parameters, especially to Ca levels. Future researches, possibly involving a higher number of KTxps could explain better these findings and explore more deeply the relation of CACs with MACE in the long term.