Time of onset and outcome of cardiogenic shock in acute coronary syndromes.

Background And Methods: The aim of our study was to evaluate the incidence, timing of the onset and outcome of cardiogenic shock in a group of 865 patients with acute coronary syndromes who were consecutively admitted to our Intensive Cardiac Care Unit (ICCU) from January 2004 to December 2005.

Results: Eighty-seven patients had cardiogenic shock; 65 (74.7%, 65/87) on ICCU admission ('early' cardiogenic shock) and 22 (25.3%, 22/87) during ICCU stay ('delayed' cardiogenic shock). Left ventricular systolic dysfunction was the cause of cardiogenic shock in 90.7% of patients (59/65) with early cardiogenic shock and in 50% of patients (11/22) with delayed cardiogenic shock (P < 0.001). Patients with early shock exhibited higher serum levels of troponin I (P = 0.029), higher serum levels of glucose on admission (P = 0.009), lower ejection fraction (=0.003), whereas latency (time from symptoms onset to percutaneous coronary intervention) was higher in patients with delayed shock (P = 0.032). Intra-ICCU mortality was comparable in the two subgroups of patients. At multivariable logistic regression analysis, age, percutaneous coronary intervention failure, glycemia on admission and the development of mechanical complications were independent predictors of intra-ICCU mortality.

Conclusion: Primary percutaneous coronary intervention has reduced the number of patients who develop cardiogenic shock after ICCU admission. According to our results, cardiogenic shock in patients with ST-elevation myocardial infarction developed early after symptoms' onset and, despite optimal treatment, mortality in these patients remains high (about 50%). Delayed cardiogenic shock is mainly due to mechanical complications as well as due to PCI complications.