2 The condition, current treatments and procedure
2.1 Additional support for the heart is not usually needed with angioplasty or percutaneous coronary intervention. However, a subset of high-risk patients may benefit from some form of heart support during their angioplasty procedure. This includes those with extensive or complex coronary artery disease (unprotected left main disease, last remaining vessel or multi-vessel disease), poor left ventricular function, ongoing myocardial ischemia, cardiogenic shock and comorbidity, in whom revascularisation may not otherwise be possible.
2.2 Temporary percutaneous mechanical haemodynamic support can be used prophylactically in some elective high-risk angioplasty procedures or in urgent procedures. The aim is to support the patient's circulatory system, provide blood flow to increase cardiac output, unload the ventricle and improve blood flow to maintain haemodynamic stability. This minimises myocardial ischemia and reduces the risk of haemodynamic collapse during the procedure. Intra-aortic balloon pumps or extra-corporeal pumps may be used for temporary percutaneous mechanical haemodynamic support. Percutaneous left ventricular-assist devices for haemodynamic support are sometimes used instead of intra-aortic balloon pumps or extra-corporeal pumps.
2.3 Inserting a temporary percutaneous mechanical haemodynamic support device may be done before or during percutaneous coronary intervention in selected high-risk patients, and is then taken out when the patient is stable.
2.4 The procedure is done under local anaesthesia. An introducer sheath is inserted into a large artery (usually the femoral or axillary artery) and a guidewire is passed into the left ventricle. A catheter with an integrated pump at its distal end is passed over the guidewire, into the large vessel and into the left ventricle. Fluoroscopic imaging is used during the procedure. The catheter is then attached to an automated external console, which controls the pump speed and monitors its function, allowing blood to be taken from the left ventricle and pumped into the ascending aorta.
2.5 Different miniature, catheter-based, intravascular devices are available and the precise implantation technique varies according to the device.