The Acorn CorCap Cardiac Support Device (CSD) is a new therapy for the treatment of heart failure that is designed to reduce left ventricular dilation, which is one of the most important pathophysiological mechanisms underlying the clinical syndrome of heart failure. The Acorn CorCap CSD is intended to reduce wall stress and support the heart, in order to prevent further dilation that is associated with progressive heart failure. It is designed to result in reduced left ventricular size and improve left ventricluar function, which should result in improved patient functional status.

The purpose of the study is to provide confirmatory data to demonstrate an improved benefit-risk profile in support of a Pre-Market Approval (PMA) application for the Acorn CorCap CSD when placed concomitant to Mitral Valve Repair/Replacement (MVR).

The primary efficacy objective is to evaluate patient functional status after 6 months of follow-up. The safety endpoint is perioperative (30 day) mortality.