Preemptive Transvalvular Mechanical Circulatory Support is Safe and Feasible in High-Risk Cardiac Surgery Patients: Results of IMPACT.

OBJECTIVES: To assess the safety and feasibility of Impella 5.5-protected cardiac surgery in patients with severe left ventricular dysfunction. METHODS: IMPACT is a prospective, multicenter, single-arm study assessing the safety and feasibility of initiation of transvalvular left ventricular unloading prior to separation from cardiopulmonary bypass. Eligible patients had a reduced left ventricular ejection fraction with planned elective or urgent conventional cardiac surgery. Patients were supported with the Impella 5.5 for at least 24 hours post-operation. Key exclusion criteria included pre-operative inotropic or mechanical circulatory support. A clinical events committee adjudicated endpoint events. RESULTS: One hundred subjects were enrolled at 18 sites in the United States, all of whom successfully received the Impella 5.5. Baseline left ventricular ejection fraction was 25% (IQR: 21.6, 28.9%) and STS-PROM was 4.1% (IQR: 2.5, 7.1%). The index cardiac procedure was primarily isolated coronary artery bypass graft (56%) or coronary artery bypass graft+valve (35%). Post-cardiotomy cardiac failure through hospital discharge, the primary effectiveness endpoint, occurred in 6% of subjects. The composite of all-cause mortality, stroke and new requirement for renal replacement therapy through 90 days post-operation, primary safety endpoint, occurred in 12% of subjects. The 30- and 90-day mortality were 2% and 4%, respectively. Subjects had a favorable post-operative trajectory with low perioperative VIS (VISmax <10 within 24 hours post-operation), timely extubation (14.4 hours) and acceptable hospital length of stay (13.9 days). CONCLUSIONS: Impella 5.5-protected cardiac surgery appears safe, feasible and is a promising device supported strategy for cardiac surgery patients with severe left ventricular dysfunction.