Devices in the management of advanced, chronic heart failure

Abstract

Heart failure (HF) is a global phenomenon, and the overall incidence and prevalence of the condition are steadily increasing. Medical therapies have proven efficacious, but only a small number of pharmacological options are in development. When patients cease to respond adequately to optimal medical therapy, cardiac resynchronization therapy has been shown to improve symptoms, reduce hospitalizations, promote reverse remodelling, and decrease mortality. However, challenges remain in identifying the ideal recipients for this therapy. The field of mechanical circulatory support has seen immense growth since the early 2000s, and left ventricular assist devices (LVADs) have transitioned over the past decade from large, pulsatile devices to smaller, more-compact, continuous-flow devices. Infections and haematological issues are still important areas that need to be addressed. Whereas LVADs were once approved only for 'bridge to transplantation', these devices are now used as destination therapy for critically ill patients with HF, allowing these individuals to return to the community. A host of novel strategies, including cardiac contractility modulation, implantable haemodynamic-monitoring devices, and phrenic and vagus nerve stimulation, are under investigation and might have an impact on the future care of patients with chronic HF.

Figure 1

CRT lead placement. A standard CRT system consists of a right atrial lead, a right ventricular lead (in CRT pacemaker systems) or a right ventricular defibrillation lead (in CRT defibrillator systems), and a left ventricular lead. The left ventricular lead is placed in a tributary of the coronary sinus on the left lateral or posterolateral wall. Abbreviations: CRT, cardiac resynchronization therapy; LBBB, left bundle branch block. Reprinted from Lancet 378 (9792), Holzmeister, J. & Leclercq, C. Implantable cardioverter defibrillators and cardiac resynchronisation therapy, 722–730 © (2011), with permission from Elsevier.

Figure 2

Designs of LVADs. a | Pulsatile-flow devices use positive displacement pumps to propel blood throughout the body as a healthy ventricle would do. Although pulsatile flow is seemingly more physiological, left ventricular unloading and haemodynamic improvement is comparable to that achieved with continuous-flow pumps. b | Continuous-flow devices use either centrifugal or axial-flow pumps to propel blood continuously throughout the body. These devices are more reliable, have a longer functional life, and operate more quietly than pulsatile devices. Abbreviation: LVAD, left ventricular assist device.

Figure 3

The positioning of the HVAD^® pump (HeartWare, Inc., Miami Lakes, FL, USA) within the pericardial space. Abbreviation: HVAD, HeartWare^® Ventricular Assist Device. Reprinted from J. Am. Coll. Cardiol. 57 (12), Strueber, M. et al. Multicenter evaluation of an intrapericardial left ventricular assist system, 1375–1382 © (2011), with permission from Elsevier.