Changes in Cardiac Structure and Function Following Fistula Ligation in Kidney Transplant Recipients (Cohort Study)

Abstract

Purpose: International guidelines recommend that haemodialysis access is provided by an arteriovenous fistula (AVF), which enables frequent, reliable access to the circulation, but there are no guidelines to suggest whether these AVFs need to be ligated after kidney transplantation. Cardiovascular morbidity and mortality remain high in recipients of a kidney transplant, the persistence of a patent arteriovenous fistula (AVF) after transplantation may contribute to ongoing maladaptive cardiovascular remodelling. The ability to reverse this maladaptive remodelling by ligation of this AVF is unknown. We conducted this trial to evaluate the effect of AVF ligation on cardiac structure and function in stable kidney transplant recipients. Also we studied the ability of preoperative echocardiographic and non-invasive hemodynamic measurements, including the effects of acute temporary occlusion of the fistula, to predict postoperative left ventricular diameter and mass reduction, by the closure of the fistula. Materials and Methods: Nonrandomized controlled trial. kidney transplant recipients (>12 months after transplantation with stable graft function) were divided into 2 groups. The first referred for surgical arteriovenous fistula closure. The second group didn’t receive Fistula closure (control). Standard echocardiographic parameters, heart rate, and blood pressure were assessed preoperatively (fistula closure) at baseline. These measurements were repeated 6 months after surgical closure. Findings: Seventeen kidney transplant patients were prospectively studied with 11 case and 6 controls with no fistula closure. Surgical fistula closure decreased left ventricular end-diastolic diameter and mass indexes (29.9_2.4to 27.4_2.1 mm/m2, P<0.001, and 141_37 to 132_39 g/m2, P<0.05, respectively), whereas no changes were seen in controls after a similar delay. Postoperative left ventricular end-diastolic diameter and mass reductions correlated best with the increases in total peripheral resistance (r_0.85, P<0.0001) and mean arterial blood pressure (r_0.64, P_0.006), respectively. Conclusions. Surgical closure of arteriovenous fistula reduces left ventricular diameter and mass in kidney transplant recipients.  The best predictors of those morphological changes are the rise in blood pressure and total peripheral resistance induced by temporary occlusion of the fistula. Implications to Theory, Practice and Policy: Surgical closure of persistent AV fistula after renal transplantation to correct LV geometry and improve symptoms in terms of exertional dyspnea and palpitations.