Heartware International, Inc. (HeartWare) develops and manufactures small implantable heart pumps, or ventricular assist devices, for the treatment of advanced heart failure. The HeartWare Ventricular Assist System (the HeartWare System), which includes a ventricular assist device (VAD), or blood pump, patient accessories and surgical tools, is designed to provide circulatory support for patients in the advanced stage of heart failure. The core of the HeartWare System is a continuous flow blood pump, the HVAD Pump, which is a full-output device capable of pumping up to 10 liters of blood per minute. The HeartWare System is designed to be implanted adjacent to the heart, avoiding the abdominal surgery generally required to implant similar devices. In August 2012, it acquired World Heart Corporation. As of December 31, 2012, the HeartWare System has been implanted outside of the United States at approximately 168 health care sites in 28 countries.