The Role of Impella in the Management of Cardiogenic Shock in Heart Transplant Patients at a Pediatric Center

Abstract

Purpose Graft failure after heart transplant (HTx) due to allograft rejection or coronary artery vasculopathy (CAV) can result in cardiogenic shock requiring mechanical circulatory support (MCS). We present our institutional experience with the Impella®, a percutaneous ventricular assist device (VAD), in HTx patients in cardiogenic shock due to graft failure. Methods This is a single center, retrospective review of HTx patients who underwent Impella implantation from 10/2014 to 4/2020. Demographics, device implant techniques, complications, and clinical outcomes were analyzed. Results There were 19 Impella implants in 11 HTx patients with median age and weight of 16 years (range 6-25) and 61 kg (range 23-124). Graft failure was due to rejection in 55% (6/11), CAV in 18% (2/11), and non-specific graft failure in 27% (3/11). Median time from HTx to Impella implant was 42 months (range 9-175). Impella devices included CP (n=11), 5.0 (n=5), 2.5 (n=1), and RP (n=2). Median length of support per implant was 5 days (range 3-21). Devices were placed via femoral (15/19) or axillary (4/19) arterial access. Seven patients received Impella support once with a single implant each. One patient required 3 distinct admissions for shock due to rejection and received Impella support each time. Three patients required 9 device implants during their course primarily for recurrence of heart failure (HF) after trial off device. Two of these received simultaneous support with CP and RP devices for biventricular HF. ECMO with Impella was required in 4 patients; 2 had Impella after ECMO for left heart decompression and 2 were placed on ECMO after Impella to augment cardiac support. Device related complications per patient included: device malfunction in 2, major bleeding requiring transfusion in 2, hemolysis in 5, extremity arterial thrombus in 2, intracardiac thrombus in 1, and transient foot drop in 3. There was no limb ischemia, stroke, infection, or increase in aortic insufficiency in the study cohort. Survival to hospital discharge was 91% (10/11). Six patients were explanted for recovery, 2 were transitioned to durable VAD, and 2 were bridged to HTx. Conclusion Impella is a promising temporary MCS option with an acceptable risk profile for adolescent and young adult HTx patients in cardiogenic shock due to graft failure with means to facilitate recovery or bridge to durable VAD or re-transplant.