Heartware down 26% on MVAD update

• Thinly traded micro cap HeartWare International (NASDAQ:HTWR -26.3%) slumps in early trading on increased volume in response to its progress report on its left ventricular assist device MVAD System released after yesterday's close.
• Patient recruitment in MVAD's CE Mark clinical trial, initiated in July, was suspended in September due to reported adverse events, including the occurrence of blood clots. In its investigation of the incidents, the company identified an issue related to the manufacture of the controller as well as the need to update the software.
• Yesterday, HeartWare stated that it has detected certain software algorithms that appear to increase the risk of pump-related blood clots. In parallel, it is assessing certain aspects of the pump's design to determine if changes can be made to improve performance. The efforts will take several months to complete. Any changes may require a new clinical trial so the potential restart of the current study or the time table for regulatory filings is uncertain at this point.
• Previously: Heartware investigating adverse events in MVAD CE Mark clinical trial; restart of enrollment likely delayed past November; shares off 16% premarket (Oct. 13, 2015)
• Previously: HeartWare MVAD trial underway in Europe (July 20, 2015)