Recent concepts of cardiovascular pharmacotherapy are now mainly based on results of multicentre prospective studies performed in several countries worldwide. The main disadvantage of such studies is the heterogeneity of patient-groups compared, caused by ethnic differences, variability of criteria and diverse concomitant medication. To assert internal validity of data compared, substantial section of patients (80–99 %) is often excluded before evaluation. Thus, there is always a lack of external validity – the data cannot be generalised and have only a limited predictive value for management of other groups or individual patients. Consequently, we still need reliable preclinical data from animal and human studies under well defined and uniform conditions. The importance of experimental and clinical physiology is demonstrated by well-established hemodynamic rules and pharmacodynamic correlations. Clinical physiology remains an indispensable foundation of clinical medicine which cannot be replaced by formal statistics.

        Key words: progress in cardiology, clinical studies, validity of data, physiology and clinical medicine