Outcomes of Surgically Implanted Impella Microaxial Flow Pumps in Heart Failure-Related Cardiogenic Shock

Background Patients with cardiogenic shock (CS) are increasingly treated with high-profile microaxial flow pumps (Impella 5.5), but little is known about the indications and outcomes of this support strategy in patients with CS due to heart failure (HF-CS). Objectives We sought to describe the clinical features and outcomes of patients with HF-CS treated with Impella 5.5. Methods We analyzed data from a prospective, multicenter observational study of patients with CS who had been implanted with an Impella 5.5. Adverse events, in-hospital survival rates and 6- and 12-month survival rates were analyzed in the total cohort and between patients treated with Impella 5.5 alone or with multiple temporary mechanical circulatory support (tMCS) devices. Outcomes were stratified based on native heart survival (NHS) and heart-replacement therapy (HRT). Results Of the 804 patients with CS who received Impella 5.5, 444 had HF-CS. Prior to Impella 5.5 placement, 214 (48.1%) had received other tMCS devices. The duration of Impella support was 21.1 ± 20.1 days (median: 15; IQR: 8, 26 days). Survival to discharge was 75.0% for the total cohort, 86.5% for those receiving Impella 5.5 alone, and 65.0% for those receiving multiple tMCS devices. The need for renal-replacement therapy and thrombocytopenia requiring transfusions was more common in those receiving multiple tMCS devices. Among patients with NHS, 6- and 12-month survival rates were 71.3% and 64.4%, respectively, while patients receiving HRT had survival rates > 93%. Conclusions Patients with HF-CS treated with Impella 5.5 had overall favorable in-hospital, 6-month and 12-month survival, both as a bridge to NHS as HRT.