Intra-aortic balloon counterpulsation in patients with acute myocardial infarction complicated by cardiogenic shock: The prospective, randomized IABP SHOCK Trial for attenuation of multiorgan dysfunction syndrome*
Patients undergoing percutaneous coronary intervention (PCI) for acute myocardial infarction with cardiogenic shock (CS) are often treated with intra-aortic balloon pump counterpulsation (IABP), even though the evidence to support this is limited. We determined whether IABP as an addition to PCI-centered therapy ameliorates multiorgan dysfunction syndrome (MODS) in patients with acute myocardial infarction complicated by CS.Design:
A prospective, randomized, controlled, open-label clinical trial recruiting patients between March 2003 and June 2004 (ClinicalTrials.gov ID NCT00469248).Setting:
Tertiary care university hospital.Patients and Interventions:
Forty-five consecutive patients with AMI and CS undergoing PCI were randomized to treatment with or without IABP.Measurements and Main Results:
Acute Physiology and Chronic Health Evaluation (APACHE) II scores (primary outcome measure), hemodynamic values, inflammatory markers, and plasma brain natriuretic peptide (BNP) levels (secondary outcomes) were collected over 4 days from randomization. The prospective hypothesis was that adding IABP therapy to “standard care” would improve CS-triggered MODS. The addition of IABP to standard therapy did not result in a significant improvement in MODS (measured by serial APACHE II scoring over 4 days). IABP use had no significant effect on cardiac index or systemic inflammatory activation, although BNP levels were significantly lower in IABP-treated patients. Initial and serial APACHE II scoring correlated with mortality better than cardiac index, systemic inflammatory state, and BNP levels in this group of patients. Nonsurvivors had significantly higher initial APACHE II scores (29.9 ± 2.88) than survivors (18.1 ± 1.66, p < .05). Nevertheless, discrepancies among patients within the groups cannot be ruled out and might interfere with our results.Conclusions:
In this randomized trial addressing addition of IABP in CS patients, mechanical support was associated only with modest effects on reduction of APACHE II score as a marker of severity of disease, improvement of cardiac index, reduction of inflammatory state, or reduction of BNP biomarker status compared with medical therapy alone. However, the limitations of our present trial preclude any definitive conclusion, but request for a larger prospective, randomized, multicentered trial with mortality as primary end point.