In June the National Institute for Health and Clinical Excellence (NICE) published welcome but bewildering guidelines for short term circulatory support with left ventricular assist devices (LVADs) as a bridge to cardiac transplantation or recovery.1 Welcome because the guidelines will support funding of these devices but bewildering because few, if any, guidelines for use were actually provided. The limited evidence was derived from the USA and Europe, where LVADs have been used for 20 years, and the guidelines are silent on a third potential use for these devices—their longer term use as a lifetime treatment.

First generation LVADs were designed to replace the failing left ventricle by providing stroke volume and pulsatile blood flow. Blood is taken from the ventricle and pumped in a pulsatile manner into the aorta at a rate of 4-10 litres per minute. These devices provide symptomatic relief, reverse multi-organ dysfunction, and reduce the cytokine and humoral responses to heart failure.2 Transplant survival is improved following the use of a device.3 Resting the heart and increasing coronary flow with an LVAD has marked effects on the diseased myocardium. Reduced wall tension and stroke work contribute by decreasing myocyte …