Primary percutaneous coronary intervention (PCI) and intra-aortic balloon pump counterpulsation (IABP) are established treatment modalities in acute myocardial infarction complicated by cardiogenic shock. We hypothesized that the insertion of the IABP before primary PCI might result in better survival of patients with cardiogenic shock compared to postponing the insertion to after primary PCI. We, therefore, retrospectively studied 48 patients who had undergone primary PCI with IABP because of cardiogenic shock complicating acute myocardial infarction (26 patients received the IABP before and 22 patients after primary PCI). No significant differences were present in the baseline clinical characteristics between the 2 groups. The mean number of diseased vessels was greater in the group of patients treated with the IABP before primary PCI (2.8 +/- 0.5 vs 2.3 +/- 0.7, p = 0.012), but the difference in the number of treated vessels was not significant. The peak creatine kinase and creatine kinase -MB levels were lower in patients treated with the IABP before primary PCI (median 1,077, interquartile range 438 to 2067 vs median 3,299, interquartile range 695 to 6,834, p = 0.047, and median 95, interquartile range 34 to 196 vs median 192, interquartile range 82 to 467, p = 0.048, respectively). In-hospital mortality and the overall incidence of major adverse cardiac and cerebrovascular events were significantly lower in the group of patients receiving the IABP before primary PCI (19% vs 59% and 23% vs 77%, p = 0.007 and p = 0.0004, respectively). Multivariate analysis identified renal failure (odds ratio 15.2, 95% confidence interval 3.13 to 73.66) and insertion of the IABP after PCI (odds ratio 5.2, 95% confidence interval 1.09 to 24.76) as the only independent predictors of in-hospital mortality. In conclusion, the results of the present study suggest that patients with cardiogenic shock complicating acute myocardial infarction who undergo primary PCI assisted by IABP have a more favorable in-hospital outcome and lower in-hospital mortality than patients who receive IABP after PCI.