Intra-aortic Balloon Pump Trials

Clinical experience with the intra-aortic balloon pump (IABP) spans >40 years.1 Physiological studies have demonstrated that the IABP acutely improves systemic hemodynamics, augments coronary flow, reduces myocardial oxygen demand, and can sustain coronary patency after percutaneous revascularization.2–4 These sound physiological principles, largely supportive observational data,5–7 and a historical lack of alternative percutaneous devices to provide circulatory support led to the widespread use of the IABP in cardiogenic shock secondary to acute myocardial infarction (AMI), ST-segment elevation-acute coronary syndrome without shock and also in high-risk percutaneous coronary intervention (PCI), despite a paucity of adequately powered randomized evidence to support their use. Nearly 5 decades since the introduction of IABP into clinical practice, we finally have randomized data on the efficacy of balloon counterpulsation for each of the 3 above indications.8–10 The main clinical applications for counterpulsation and the randomized data for each indication are summarized in the Table.View this table:Table. Randomized Control Trials of Intra-aortic Balloon CounterpulsationTo the surprise of many who have come to rely on the support and reassurance provided by this device, none of the recent trials reached their primary efficacy end points. Where does that leave us with the IABP? Is it time to abandon ship or is there hope yet for an old friend?Perhaps the most surprising of these randomized controlled trial (RCT) results was from the most recent trial, IABP-SHOCK II.8 This multicenter, open-labeled, randomized study enrolled 600 patients with AMI (with or without ST-segment elevation) with cardiogenic shock, if early revascularization was planned. Patients were randomized in a 1:1 ratio to intra-aortic balloon counterpulsation (IABP group) or no intra-aortic counterpulsation (control group). The primary study end point, 30-day all-cause mortality, occurred in a similar proportion of the IABP and control groups (39.7% …