P61: Novel use of newer intravascular ambulatory systemic ventricular assist devices as a bridging strategy for cardiogenic shock with pulmonary hypertension in patients with complex congenital cardiac conditions

Background: Cardiogenic shock [CS] in patients with failing systemic ventricles is associated with high mortality. Suitable patients maybe successfully bridged using newer intravascular ambulatory left ventricular assist devices [Impella 5.5, Abiomed, Danvers, MA] as a bridge to transplantation. We report our successful experience with two such patients. Methods: Between January 2022 and January 2023, 2 patients underwent trans-axillary artery placement of LV Impella 5.5 for CS as a bridge to heart transplant. Both these patients had previously undergone a Senning operation for transposition of the great arteries, and presented with failing systemic ventricle with pulmonary hypertension. Results: Two patients [patient 1: 36 years, patient 2: 38 years] presented to our unit with cardiogenic shock. They underwent trans-axillary artery placement of LV Impella 5.5 into the systemic ventricle for CS as a bridge to decision for high pulmonary vascular resistance [PVR]. Heart and lung transplantation was considered, but the patients declined and opted to pursue strategy for heart transplant alone. Following 30 and 50 days on impella 5.5 support in patients 1 and 2 respectively, along with intravenous diuretics and milrinone 0.25mcg/kg/min, there was reversal of pulmonary hypertension [Table-1]. Both patients underwent successful redo-sternotomy and heart transplantation. Second patient required 48-hours of extra-corporeal membrane oxygenator [ECMO] support for primary graft dysfunction, increased immunosuppression for grade 2 rejection, and temporary renal replacement therapy. Both patients recovered and were discharged home. Conclusions: We report successful outcomes in these two patients who had previously undergone complex congenital heart surgery, and had presented to us in cardiogenic shock with failing systemic ventricles and severe pulmonary hypertension, which hitherto would have precluded cardiac transplantation alone. Utilization of Impella 5.5 for cardiogenic shock in these patients facilitated successful reversal of pulmonary hypertension and therefore, a successful cardiac transplantation without resorting to durable VAD placement or heart-lung transplantation in this difficult cohort of patients. Furthermore, impella 5.5 placement helped avoid femoral ECMO completely, with its inherent problems of immobility, bleeding, infections, limb ischemia, and muscle wasting, and greatly facilitated early ambulation and rehabilitation while awaiting a suitable organ. Table 1. - Pre transplant hemodynamics in both patients PAS PAD PAM PCWP TPG PVR RA CI CO PA Sat P1 Baseline 80 50 60 38 22 10 22 1.1 2.2 34% P1 Day-30 impella 45 20 28 18 10 2 7 2.7 5 59% P2 Baseline 88 50 64 41 23 4.8 18 3 4.7 58% P2 Day-50 impella 57 26 36 16 20 2.5 7 4 7.3 74% PAS/D/M: pulmonary artery systolic/diastolic/mean pressures; PCWP: pulmonary capillary wedge pressure; TPG: trans pulmonary gradient; RA: right atrial pressure. All in mmHg. PVR: pulmonary vascular resistance in wood units CI: cardiac index in liters/minute/square meter body surface area; CO: cardiac output in liters/minute; PA sat: pulmonary artery oxygen saturation