The cardiac support device and the myosplint: treating heart failure by targeting left ventricular size and shape

Left ventricular (LV) remodeling occurs in patients with heart failure and is associated with poor long-term outcome. Two important components of this remodeling process are progressive LV dilation and LV shape changes, the latter manifested by increased LV chamber sphericity. This brief review describes two passive mechanical devices that were developed to prevent the progressive LV dilation and shape changes that occur during the evolution of heart failure. One such device is the Cardiac Support Device ([CSD] CorCap; Acorn Cardiovascular, St Paul, MN) and the other is the Myosplint (Myocor, Maple Grove, MN). Studies in dogs with coronary microembolization-induced heart failure have shown that the CSD prevents progressive LV dilation, increases LV ejection fraction, lowers LV wall stress, and attenuates LV chamber sphericity. Safety and feasibility studies in patients with heart failure have shown that the CSD is safe. The same studies have provided strong efficacy trends that are consistent with those seen in experimental animals. Studies in dogs with rapid pacing induced heart failure showed that the Myosplint device can reshape the LV leading to reduced LV volumes, increased ejection fraction, and reduced wall stress. Safety and feasibility studies of the Myosplint device in humans are limited and trends are not as yet easily discerned. Final conclusions on the clinical effectiveness of these devices must await completion of randomized clinical trials. These trials should provide the first tests in humans of the hypothesis that limiting LV remodeling alone can improve long-term outcome and quality of life in patients with heart failure.