The European Registry of Cardiac Catheter Interventions 1997.

A detailed questionnaire with instructions and examples was mailed to the presidents or designated delegates of the national societies of cardiology represented in the European Society of Cardiology. They distributed a copy of the questionnaire to all institutions performing diagnostic or interventional cardiac catheterizations in their respective countries. Upon completion the questionnaires were returned to the representatives to be compiled in a national summary data sheet. The summary data sheets were entered into a central database and subsequently analysed. No data were received from Cyprus and Ireland until entry closure. Sufficiently complete surveys were available from 29 countries representing more than 550 million people in Europe. The definitions of diseases and procedures were used according to previously published reports.