[Risk of cardiological interventions].

The risk of cardiac interventions has to be assessed in relation to the possible benefit and in comparison to the natural history and to alternative interventions. The relationship between complications (mortality, morbidity) and age, severity of the disease, gender and technique on one hand, and between risk of the intervention versus risk of uninfluenced natural history on the other, are discussed. Diagnostic, therapeutic and prophylactic interventions are presented separately; the benefit needs to be defined differently for each: diagnostic accuracy or symptom relief, improved quality of life and survival, and prolonged life respectively. Finally, it is stressed that the choice of an intervention is not only dependent on the determinants of risk, but also on the availability of a certain method, operator experience, cost and, last but not least, patient preference.