Left Ventricular Assist Devices

Heart failure (HF) is a frequent cause of inpatient admissions. The Framingham study in 1993 described the risk factors for heart failure and showed unacceptably high five-year mortality rates of 25% in men and 38% in women . The American Heart Association reported the prevalence of HF to be 5.1 million in the United States in 2006 . The worldwide prevalence has been estimated to be 23 million .HF can be categorized based on the left ventricular ejection fraction (LVEF) into systolic and diastolic HF. The former group includes patients with LVEF less than or equal to 40%, also termed heart failure with reduced ejection fraction (HFrEF). Heart failure with preserved ejection fraction (HFpEF) includes those with LVEF greater than or equal to 40%. The multiple modalities of treatment available to treat HF include but are not limited to lifestyle modifications, pharmacologic agents, device therapies such as implantable cardioverter-defibrillator (ICD), and cardiac resynchronization therapy (CRT). At times, failure to improve could necessitate short-term mechanical circulatory support with the use of an intra-aortic balloon pump (IABP) or even extracorporeal membrane oxygenation (ECMO). However, a large population of patients continues to have advanced heart failure with worsening LVEF despite maximal therapy.Circulatory support with the use of a left ventricular assist device (LVAD) is an emerging field. The landmark REMATCH trial that compared LVADs with optimal medical therapy in class IV HF patients found a 48% reduction in mortality from any cause . There was also a significant increase in the survival rates at one year (52% versus 25%) and two years (23% versus 8%). The definitive treatment for advanced HF (class II and IV) is cardiac transplantation . However, with the limited number of donor hearts available, LVADs are life-saving.