Reduction of left ventricular diameter and mass after surgical arteriovenous fistula closure in renal transplant recipients

BACKGROUND: Left ventricular hypertrophy and dilatation is a frequent finding in kidney transplant recipients, which may be favored by the persistent patency of arteriovenous fistula. The purpose of the current study was to prospectively investigate whether surgical closure of the fistula allows reduction of abnormalities of left ventricular morphology in stable renal transplant patients. Furthermore, we studied the ability of preoperative echocardiographic and noninvasive hemodynamic measurements, including the effects of a temporary occlusion of the fistula, to predict postoperative left ventricular diameter and mass reduction.

METHODS: Seventeen kidney transplant recipients referred for surgical arteriovenous fistula closure were prospectively studied. Standard echocardiographic parameters, heart rate, and blood pressure were assessed preoperatively at baseline and during an acute pneumatic fistula occlusion. These measurements were repeated 3 to 10 weeks after surgical closure. Six kidney transplant recipients with patent arteriovenous fistulas referred for routine echocardiographic follow-up served as a control group.

RESULTS: Surgical fistula closure decreased left ventricular end-diastolic diameter and mass indexes (29.9+/-2.4 to 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) during pneumatic occlusion, respectively.

CONCLUSIONS: Surgical closure of arteriovenous fistula reduces left ventricular diameter and mass in kidney transplant recipients. Increases in blood pressure and total peripheral resistance induced by temporary fistula occlusion are the best predictors of these morphological changes.