Introduction A central stent derived arterio-venous iliac fistula using the ROX Coupler reduces blood pressure (BP) in patients (pts) with resistant and/or uncontrolled hypertension (HTN). We performed detailed stress echocardiograms (echos) during concurrent cardiopulmonary exercise testing (CPET) pre and post insertion of a ROX Coupler for HTN. We evaluated the pre and post ROX Coupler characteristics of pts who might progress to cardiac decompensation.

Methods 8 pts aged 46–78 (75% male) underwent CPET echos at baseline and between 1 and 6 months following ROX Coupler insertion. 1 pt had evidence of late decompensation with persistent ankle swelling not associated with venous stenosis and IVC>2.5 cm

Results Interim analysis suggests there were no significant differences for any CPET parameter before and after coupler insertion. However TR Vmax, a surrogate for pulmonary artery systolic pressure, significantly increased from 1.96±0.94 m/s to 2.08±0.94 m/s, p=0.01. Meanwhile, lateral E/E, a marker of left ventricular filling pressure, significantly decreased from 12.7±7.2 to 10.7±3.8, p=0.005.

Conclusions A lower E/E lateral post ROX suggests the left ventricular filling pressure is reduced and the heart is working at a more efficient match of preload and afterload resulting in reduced cardiac oxygen consumption and reduced myocyte stress. An ongoing study is assessing the effect of the ROX Coupler upon AF outcomes by reversing the structural and electrical effects induced by longstanding HTN. These findings may support this hypothesis.