BACKGROUND: Patients with ST-segment elevation myocardial infarction (STEMI) and cardiogenic shock (CS) have a high risk of death. New types of mechanical devices have limited availability in Brazil. The use of intra-aortic balloon pump (IABP), although new guidelines downgraded its recommendation, is the most widely used mechanical support strategy. However, little is known about the clinical predictors of its effectiveness in reducing mortality in this group of patients. OBJECTIVES: To assess the predictors of IABP effectiveness in reducing in-hospital mortality in patients with STEMI and CS. METHODS: This observational, retrospective, descriptive, single-center study involved 98 patients with STEMI and CS treated with IABP, in an intensive care unit. We compared patients who survived (42 men and 13 women) and those did not (30 men and 13 women) using clinical predictors of IABP effectiveness in reducing in-hospital death, considering a statistical significance level of 5% (p <
0.05). RESULTS: The use of IABP in patients less than 1 day after infarction (odds ratio [OR]: 0.12
95% confidence interval [CI]: 0.02 to 0.85
p = 0.034) was a factor that increased the risk of in-hospital death. Younger age (OR: 1.09
95% CI: 1.02 to 1.16
p = 0.010) and dyslipidemia (OR: 0.19
95% CI: 0.05 to 0.81
p = 0.024) were predictors of reduced in-hospital mortality. For each additional year of age, the risk of death increased 1.07-fold. CONCLUSION: In patients with STEMI and CS, the use of IABP reduced in-hospital mortality when it was used for 2 or more days, as well as in younger patients and those with dyslipidemia. Additional studies are needed to confirm these findings.