Abstract 2062: Efficacy of Intra Aortic Counterpulsation in Patients with ST-Elevation Myocardial Infarction Complicated by Cardiogenic Shock
Background The clinical treatment guidelines for ST-elevation myocardial infarction (STEMI) strongly recommend additional intra-aortic balloon counterpulsation (IABP) in STEMI patients with cardiogenic shock (CS) or pre-shock treated by PCI. However, there is no randomized evidence for a survival benefit. It is suggested that timing of initiation of IABP therapy is of great importance. However, this is one of the feasibility and efficacy aspects that is not well formalized. Therefore, we examined the relation between different times of initiation of IABP therapy and mortality rates.
Methods From 1997 to 2005 414 consecutive STEMI patients with CS or pre-shock treated with primary PCI were included. From this cohort 321 patients received IABP (IABP group) and 93 patients received no additional support (no IABP group). The IABP group was divided in 3 subgroups based on the initiation of support, i.e. the ‘IABP-pre PCI’ group (n=83), ‘IABP-during PCI’ (n=42) and ‘IABP-post PCI’ group (n=195). As, heterogeneity in baseline risk is known to exist in CS and pre-shock patients, risk stratification models were constructed based on hemodynamic parameters (HD score) and inotropic usage (inotropic score). After stratification of all patients into high and low risk, all-cause mortality was assessed between the no-IABP group and respectively the total IABP group and IABP subgroups.
Results Overall 1-year mortality for the IABP versus the no IABP group was respectively 46% vs. 30%. According to the HD score mortality rates for the IABP pre PCI, during PCI and post PCI vs. no IABP in the low risk group respectively were 51,7%, 30,4%, 26,5% and 19,4% (p = 0.015) and in the high risk group respectively were 65,4%, 61,1%, 56,7% and 50,0% (p = 0.580). Stratification by inotropic score showed similar mortality rates.
Conclusion There was no beneficial effect of additional IABP with respect to 1-year mortality in STEMI patients with CS or pre-shock treated with PCI after stratification for baseline risk and timing of initiation of IABP therapy. IABP in low risk patients was associated with increased mortality, particularly in those receiving IABP pre PCI. In high risk patients there was no difference in mortality between those receiving no IABP or IABP therapy, irrespective of timing.