The Effect of Elective Ligation of the Arteriovenous Fistula on Cardiac and Renal Functions in Kidney Transplant Recipients.

Abstract

Kidney transplantation (KTx) is considered as the best kidney replacement therapy and arteriovenous fistula (AVF) is the preferred vascular access for hemodialysis. The systematic ligation of a functioning AVF in stable kidney transplant recipients remains debatable. In this prospective study, we investigated the hemodynamic impact of the surgical closure of AVF in KTRs. Forty-three KTRs underwent an ambulatory blood pressure monitoring (24h-ABPM) before surgical closure of AVF (T0) and 12 months later (M12), as well as measurement of serum cardiac biomarkers (i.e., soluble suppression of tumorigenicity 2 (ST2), N-terminal pro b-type natriuretic peptide (NT-proBNP) and Galectin-3). Serum tests were also performed 6 months after AVF closure (M6). An echocardiographic exam was done at each time-point. All serum creatinine values were collected to compare the individual eGFR slopes before versus after AVF closure. The latest measure of the AVF flow (QAVF) prior to KTx was recorded. Diastolic blood pressure (DBP) significantly raised from T0 to M12: + 4.4±7.3 mmHg (p=0.0003) for 24h, + 3.8±7.4 mmHg (p=0.0018) during the day, and + 6.3±9.9 mmHg (p=0.0002) during the night, leading to an increased proportion of KTRs with ESH-defined arterial hypertension after AVF ligation. No change was observed for systolic BP. NT-proBNP significantly dropped between T0 and M6 (345 [190; 553] to 230 [118; 458] pg/mL, p=0.0001) and then remained stable from M6 to M12, while ST2 and Galectin-3 levels did not change from T0 to M12. We observed a significant decrease of left ventricular (LV) end-diastolic volume, LV end-systolic volume, LV mass, interventricular septum diameter, left atrial (LA) volume, and tricuspid annular plane systolic excursion from T0 to M6, and then a stability from M6 to M12. LV ejection fraction and eGFR slope remained stable during the whole study. These observations remained unchanged after adjustment for QAVF. The closure of a patent AVF in KTRs is associated with elevation of DBP, drop of serum NT-proBNP levels, reduction of LV/LA dimensions, and stable eGFR slope.