BACKGROUND: The IMACS Registry compiles and analyzes worldwide data from patients undergoing implantation of durable left ventricular assist devices. METHODS: Data encompassing 16,286 LVAD recipients from 4 collectives and 24 individual hospitals was collected and analyzed. In this 3rd annual report we compare and contrast outcomes, adverse events and risks factors between axial flow and centrifugal flow device recipients. RESULTS: Significant differences were found in the baseline characteristics of axial vs centrifugal flow LVAD recipients. Survival was similar between pump types. INTERMACS profile 1-3 constitute 85% of implants. A survival gap persists in destination therapy compared to bridge patients. RVAD need and delay impact survival dramatically. Centrifugal flow outperforms axial flow recipients in regards to GI bleeding and freedom from hemocompatibility related adverse events. No significant difference in the actuarial freedom from all strokes or either stroke subtype (hemorrhagic or ischemic) was seen among the two types of pumps. New end points to guide decision making are proposed. CONCLUSIONS: We demonstrate a transition from axial to centrifugal flow with four-year survival that approximates 60%. A high frequency of adverse events remains an impediment to the wider adoption of these technologies. In the future, composite study endpoints examining life quality and adverse events beyond survival may help in shared decision making prior to MCS implant, and may provide the requisite data to support extension of MCS therapy into the lesser ill heart failure population.