Clinical Implications of Cardiac Assisted Devices in Low Cardiac Output Syndrome

Abstract

Low cardiac output states are more common in patients with heart failure. Heart failure is the final common pathway for many chronic heart diseases. With the aging of population and advances in the treatment of cardiac diseases, the number of patients with heart failure continues to increase. For selected patients who are too ill to wait for a heart donor or who are not eligible for a heart transplant because of age or other medical problems, ventricular assist devices offer lifesaving therapy. For more than 4 decades, the medical device industry has been pursuing the development and refinement of mechanical cardiac support. Cardiac mechanical assist devices are used during periods of hemodynamic instability and persistent low cardiac output in an attempt to restore normal hemodynamic parameters. The primary goal of their use is to normalize inflow and drainage of vital organs so that kidney and liver function return to normal with improved hemostatic potential. The deleterious effects of elevated atrial pressure on many of the major organs are well known, with the lungs being most adversely affected. Increased central venous pressure is also particularly detrimental to the liver and kidneys, causing outflow disorders that compromise organ function. Elevated atrial and central venous pressures, secondary to ventricular dysfunction, are often rapidly normalized by the use of cardiac mechanical assist devices. In general the patients with severe pulmonary disease, blood dyscrasias, psychiatric disorders (in which suicidal attempts can be successful by simply unplugging the device or incompliant behavior may interfere with device function) and irreversible organ dysfunctions are not good candidates for mechanical assist devices. VADs are used as a bridge to recovery, bridge to transplantation destination therapy, or bridge to candidacy. Bleeding, thrombosis, infection and right ventricle dysfunction are complications seen with mechanical assist devices. Appropriate selection of candidates and timing of LVAD implantation are critical for improved outcomes of destination therapy. Patients with advanced heart failure who are referred for destination therapy before major complications of heart failure develop have the best chance of achieving an excellent 1-year survival with LVAD therapy. Cardiac assist device is still the future in medicine for cardiac patients all over the world.