This is a registry of the patients that are admitted to CICU and treated by the Scientific Staff of the 2nd Department of Cardiology, due to an acute cardiovascular disease (acute coronary syndrome, acute heart failure, arrhythmia, pulmonary embolism, cardiac tamponade etc) in order to investigate the clinical characteristics of the patients, their outcome, identify the factors that could predict the in-hospital mortality and compare the results with the predicted by established risk scores. Furthermore, the study will investigate the one-year mortality and also the major adverse cardiac events (MACE - acute myocardial infarction, stroke, or cardiovascular death) will be measured.