Low Flow Alarms! A Case of Percutaneous LVAD Decommissioning

Abstract

<h3>Introduction</h3> Low flow alarms (LFA's) in LVAD can occur due to a multitude of conditions. The differential diagnosis includes: hypovolemia, tamponade, right ventricular failure, hypertension, arrythmias, inflow cannula malposition, outflow cannula obstruction, and pre-pump inflow cannula thrombosis. We present a case of a patient with an HVAD with persistent LFA's and apparent myocardial recovery. <h3>Case Report</h3> A 44 y/o female who underwent destination therapy HVAD placement three years prior presented with one week of asymptomatic LFA's with low pulsatility. Device speed prior to presentation was 2400 RPM (flow 3 L/min, 6.4 L pulsatility, power 2.7 W); on presentation mean flows were 0.5 L/min, peak and trough 2.4 and 0 L/min, MAP was 59 mm Hg. TTE showed normal cannula position, closed aortic valve, mild right ventricular dysfunction. No arrythmias were present. LDH and plasma free Hgb were within normal limits. A controller exchange did not resolve LFA's. CT angiography showed no outflow graft obstruction. Invasive hemodynamics at 3100 RPM showed (mm Hg): RA pressure 8, RV pressure 42/8, PA pressure 40/14/28, PCWP 14/14/11, and cardiac index 4.3 L/min/m². Given no obvious cause of LFA and apparent myocardial recovery, we opted for percutaneous device decommissioning, given poor candidacy for surgical explant. Under general anesthesia and full heparinization, device speed was lowered to 1800 RPM for 5 minutes, during which invasive hemodynamics remained stable. A 0.035 inch Rosen wire was placed into the outflow graft with subsequent exchange to a long 6-French sheath into the outflow graft. A 12-mm Amplatzer vascular plug was then deployed into the outflow graft with subsequent ventriculogram demonstrating retrograde flow (Figure). The device was powered off, the driveline buried, and the patient discharged with lifelong coumadin (INR 2-3) & Aspirin 81 mg. <h3>Summary</h3> This case demonstrates feasibility of percutaneous LVAD decommissioning in patients with myocardial recovery or device-related complications not amenable to surgical explant.