Abstract
BACKGROUND: Guidelines strongly recommend additional intra-aortic balloon pump (IABP) therapy in STEMI patients with cardiogenic shock (CS) treated by primary percutaneous coronary intervention (PCI). However, there is no randomised evidence suggesting survival benefit of IABP treatment in CS. It is suggested that timing of initiation of IABP therapy could be of great importance. Therefore, we compared mortality rates of IABP therapy versus no IABP therapy in the setting of STEMI complicated by CS. In addition, we investigated the effect of initiation of IABP therapy on mortality. METHODS: From a cohort of 292 STEMI patients with CS treated by primary PCI, 199 patients received IABP therapy (IABP group) and 93 patients received no support (no IABP group). The IABP group was divided into two subgroups based on timing of initiation of support, i.e. 'IABP pre PCI' (n = 59) and 'IABP post PCI' (n = 140). Outcomes were assessed by propensity stratification and multivariate logistic regression. RESULTS: All-cause 30-day mortality for the IABP versus the no IABP group was 47 % vs. 28 %, respectively, in univariate analysis resulting in an odds ratio (OR) of 1.67 (95%CI, 1.16 to 2.39). However, analyses adjusting outcomes by propensity stratification and logistic regression, respectively, neutralised this OR. In the IABP pre-PCI group vs. the post-PCI group 30-day mortality was 64 % vs. 40 %, resulting in an OR of 1.56 (95 % CI, 1.18 to 2.08). However, after propensity stratification analysis and multivariate logistic regression analysis, there were no significant differences in odds of 30-day mortality. CONCLUSION: In our cohort of patients with STEMI complicated by CS treated with primary PCI we observed a difference in mortality between those treated with IABP and those treated without IABP in favour of the 'no IABP' group. The mortality difference was eliminated after adjustment for differences in case mix by propensity stratification or by logistic regression analysis. Neither did we observe any difference in mortality between patients whose IABP treatment was initiated before or immediately after PCI.