FRAMINGHAM, Mass., May 1, 2014 /PRNewswire/ -- HeartWare International, Inc. (Nasdaq: HTWR), today issued a voluntary Urgent Medical Device Correction related to all HeartWare ® Ventricular Assist System batteries, product codes 1650 and 1650-DE. In letters to clinicians and patients, the company reports an observed increase in complaints related to earlier-than-expected battery depletion and routine battery handling. HeartWare is providing information to assist patients and clinicians in monitoring battery performance, recognizing abnormal behaviors and reinforcing proper power management. Premature or unrecognized deterioration of battery capacity or lapses in recommended power management pose a risk to the patient and, although rare, may result in serious injury or death. If a battery shows abnormal behavior, patients are instructed to stop using that battery and contact their VAD Coordinator for a replacement. Similar to the battery in a mobile cell phone, HeartWare ® batteries will begin to lose charge over time. If a fully-charged battery lasts less than two hours or if the controller switches back-and-forth between batteries, patients are asked to take the affected battery out of service and replace it with a new one. No deaths have been reported to HeartWare that were directly related to a faulty battery. However, between January 1, 2011 and March 31, 2014, three deaths were reported that were potentially related to power source management. Of those, two patient deaths occurred after both sources of power were simultaneously disconnected; the third patient had batteries that far exceeded their expected useful life. A fourth death was originally reported as possibly related to power management, but was later determined to be more likely related to an accidental disconnection of the driveline. Clinicians and patients are encouraged to review the correction letters and the Patient Manual to ensure proper power management.