In the UK most patients undergoing diagnostic catheterisation and interventional cardiac procedures are treated in National Health Service (NHS) hospitals. However, a number of private hospitals also undertake such procedures and are reimbursed through other mechanisms such as private health insurance, overseas contracts, or patient self funding, and some of these patients are foreign nationals. Also, a small number of privately funded patients have their procedures undertaken in NHS hospitals, and an even smaller number of NHS patients have their procedures contracted to the private sector. These variations make it difficult to make accurate assessments of national activities per head of the UK population. Nevertheless, around 90% of all interventional procedures are undertaken in NHS hospitals and over 95% of these patients are UK citizens being treated under the NHS. This allows us to make a reasonable estimate of national activity with regard to coronary intervention.

Over the last decade there has been a considerable expansion in the number of diagnostic catheter procedures being undertaken in laboratories situated in district general hospitals, and there has been an expansion in the number of consultant cardiologists. More recently, mobile laboratories have also been used by a number of district hospitals. In contrast, the number of centres undertaking interventional procedures has changed very little; this may reflect the ability of existing centres to increase the volume of procedures undertaken and concerns about the need for sites to have on site cardiac surgery.

The interventional procedures reported here refer to the total number of procedures undertaken. Since some patients will undergo more than one procedure in a single calendar year, the number of interventions does not equate with the number of patients treated.