CHAPTER SUMMARY AND CENTRAL ILLUSTRATION
This chapter explores the current status of mechanically assisted circulation and cardiac transplantation. Since the first successful heart transplant in 1967, refinements to candidate and donor selection and management, manipulating the immune system, and surveillance for acute and chronic complications have been associated with progressively improved outcomes. Contemporary median survival following heart transplant is 12.5 years, extending to 14.8 years in those surviving the first year after the procedure. Similarly, mechanically assisted circulation using left ventricular assist devices (LVADs) has become a standard of care for patients failing medical therapies awaiting transplantation or in those ineligible for transplant (see Fuster and Hurst’s Central Illustration). Newer devices are small, continuous flow pumps with enhanced hemocompatibility to minimize bleeding and thrombosis complications. The mean survival after LVAD implantation is nearly 5 years. Patient selection approaches for mechanical and biologic replacement, as well as the roles for palliative care and shared decision-making in supporting the patients with advanced heart failure and their families, are discussed.
eFig 52-01 Chapter 52: Mechanical Circulatory Support and Heart Transplantation in Severe Heart Failure
Despite major advances in the treatment of end-stage heart disease, patients with refractory heart failure (HF), progressive angina, or uncontrolled ventricular arrhythmias often cannot be stabilized with medical therapy. Thus, surgical management of these patients including mechanical circulatory support devices and heart transplantation are established options to improve quality and quantity of life in carefully selected patients.
Although cardiac transplantation remains the gold standard treatment for stage D HF, the worldwide donor shortage has resulted in highly selective criteria and long waiting times for a suitable organ. The option of mechanically assisted circulation as a viable treatment alternative for this population has gained gradual acceptance over the last decade. The original mechanical blood pumps were designed to replicate the human heart, resulting in large, pulsatile devices with a normal adult stroke volume. The conceptual model of assisted circulation has evolved to smaller, less complex continuous flow pumps. The interagency registry for mechanically assisted circulation (INTERMACS) has documented the growth of the field with detailed clinical information on more than 24,000 individual patients treated with mechanical circulatory support in the United States.1
The need for mechanical circulatory support is dependent upon the patient’s presentation. Patients who present in cardiogenic shock may require acute or short-term circulatory support that may serve as a bridge to heart transplantation but only if stability and recovery of multiorgan system dysfunction can be achieved. In the new US donor heart allocation policy (October 2018), patients who have met criteria for cardiogenic shock and have stabilized with short-term devices have the highest priority for donor hearts. This change in policy appears to have led to the increased use of short-term mechanical circulatory support for these patients.2...