Intra-Aortic Balloon Counterpulsation Before Primary PCI Does Not Reduce Infarct Size

The benefits of intra-aortic balloon counterpulsation (IABC) in patients with myocardial ischemia and cardiogenic shock are well established. To investigate whether IABC before primary percutaneous coronary intervention (PCI) reduces infarct size in patients without cardiogenic shock, investigators for this manufacturer-funded, multicenter, randomized, open-label trial assigned 337 patients with anterior ST-segment-elevation myocardial infarction (STEMI) to receive or not to receive IABC before PCI. In IABC recipients, treatment continued for at least 12 hours after PCI (median treatment time, 22 hours).

More than 95% of participants (median age, 57; >80% men) had left anterior descending infarcts. All were hemodynamically stable at randomization, but IABC became necessary and was deployed in 8.5% of the PCI-alone group either before or after PCI; mortality was high in these crossover patients (27% at 30 days vs. <5% in the entire study population). The primary endpoint, infarct size as determined by magnetic resonance imaging 3 to 5 days after PCI, did not differ significantly between the IABC and no-IABC groups (left ventricular mass, 42% and 38%, respectively), nor were any between-group differences found in the subgroup with initial Thrombolysis in Myocardial Infarction flow of 0 or 1 and after adjustment for baseline ST elevation. Clinical endpoints, including death, recurrent MI, or congestive heart failure, also did not differ between the groups at 30 days and 6 months. IABC use was associated with a trend toward an increased rate of major vascular complications.