Adding to the "don't do anything, just stand there!" file, another relatively frequently used cardiovascular support tool – intra-aortic balloon counterpulsation – might be on the chopping block.
Typically used in cases of severe cardiogenic shock secondary to acute myocardial infarction, IABP is used to reduce strain on the stunned myocardium. The first IABP-SHOCK pilot of 45 patients showed no mortality difference, but a significant improvement in BNP levels with IABP use. This is the follow-up study, enrolling 600 patients to IABP or best available medical therapy.
Both groups were similarly ill – the IABP group had 6% more anterior STEMIs – and had nearly identical outcomes. There were 1.5% more survivors in the IABP group, but the p value was 0.69. Adverse events were similar – although the control group tended towards increased sepsis, which seems a little odd. There was an expected random assortment of subgroups favoring one therapy or another, but nothing that would seem to be specifically hypothesis generating.
In the end, the authors rather grimly state that, despite some surrogate markers appearing to be improved in the IABP group, there is no evidence to support routine use of IABP in cardiogenic shock secondary to acute myocardial infarction.
"Intraaortic Balloon Support for Myocardial
Infarction with Cardiogenic Shock"