ATLANTA, Sept. 13, 2007 (PRIME NEWSWIRE) -- CardioMEMS, Inc. today announced that its wireless pressure sensor for heart failure (HF) monitoring was successfully implanted in two patients at Saint Thomas Hospital, Nashville, Tennessee under the direction of Mark Aaron, MD, Medical Director, Cardiac Transplant, Comprehensive Heart Failure and Transplant Program, St. Thomas Heart Institute. These patient implants mark the initiation of the CHAMPION (CardioMEMS Heart Sensor Allows Monitoring of Pressure to Improve Outcomes in NYHA Class III Patients) pivotal clinical study.