The hemodynamic effects of a central iliac arteriovenous anastomosis at 6 months in patients with resistant and uncontrolled hypertension

Abstract

A central iliac arteriovenous anastomosis, termed the “coupler” (ROX Medical), results in a significant reduction in blood pressure (BP) in hypertensive patients. This study assessed functional and hemodynamic changes induced by the device. Twenty-one patients with resistant and/or uncontrolled hypertension underwent stress echocardiography and cardiopulmonary exercise testing (CPET) at baseline and 6 months post-coupler implantation. End points were selected to best evaluate cardiac function including Doppler stroke volume (SV), septal and lateral E/E′, and right ventricular systolic velocity S′ (RV S′). CPET VO2 peak demonstrated total cardiopulmonary performance. SV increased from 76.4 SD12.2 mL to 92.1 SD22.7 mL 6 months post-coupler insertion; P =.002. No changes in RV S′, septal or lateral E/E′, or VO2 peak were observed. Five patients experienced increased diuretic requirement ≥3 times baseline. RV S′ fell from 19.0 SD1.87 cm/s to 16.80 SD3.43 cm/s in these patients (P '.05). A significant increase in SV 6 months post-coupler insertion was observed. In patients with increased diuretic requirement, the device was associated with a lower RV S′ suggesting occult RV dysfunction as the mechanism of this pre-specified adverse outcome.