Despite a lack of evidence, circulatory support with intraaortic balloon counterpulsation (IABP) has a class 1 recommendation in the guidelines and is often used in patients in cardiogenic shock following myocardial infarction for whom early revascularization is planned. That situation may change soon, as no benefit was found for the use of IABP in the first large trial of the strategy.
The IABP-SHOCK II (Intraaortic Balloon Pup in Cardiogenic Shock II) was presented at the ESC and published simultaneously in the New England Journal of Medicine. Trial investigators, led by Holger Thiele, randomized 600 acute MI patients in cardiogenic shock to either IABP or no IABP. At 30 days there were no significant differences in mortality, the primary endpoint of the study:
- Mortality: 39.7% in the IABP group versus 41.3% in the control group (relative risk with IABP 0.96, CI 0.79-1.17, p=0.69)
There were no significant differences between the groups in secondary endpoints, process-of-care outcomes, or safety endpoints, including stroke and bleeding.
In an accompanying editorial, Christopher O’Connor and Joseph Rogers write that the trial “could have affirmed contemporary clinical practice and guidelines” but, “instead, it revealed surprising results.”
“Members of guidelines committees and clinicians should take note of another example of a recommendation that is based on insufficient data,” they wrote.
Republished with permission from CardioExchange, a NEJM group publication.