August 30th, 2011
No Benefit for Routine Counterpulsation Found in CRISP AMI
Routine use of intra-aortic balloon counterpulsation (IABC) in STEMI patients who do not have cardiogenic shock does not reduce infarct size, according to a new trial. Results from the CRISP AMI (Counterpulsation to Reduce Infarct Size Pre-PCI Acute Myocardial Infarction) trial were presented at the European Society of Cardiology meeting in Paris by Manesh Patel and published simultaneously in JAMA.
Some 337 STEMI patients at 30 sites were randomized to either standard care or routine IABC placement prior to reperfusion. There were no significant differences between groups in infarct size expressed as a percentage of LV mass as measured by MRI 3 to 5 days after PCI:
- 42.1% in the IABC group compared with 37.5% in the standard care group. This 4.6% difference was not significant (p=0.06).
The same pattern was observed in patients with large infarcts (proximal LAD and TIMI flow scores of 0 or 1):
- 46.7% in the IABC group compared with 42.3% in the standard care group. The difference of 4.4% was not significant (p=0.11).
Fifteen patients in the standard care group crossed over and received IABC. IABC treatment resulted in a short but significant delay to treatment: The time from first contact to first coronary device was 68 minutes in the standard care group and 77 minutes in the IABC group (p=0.04).
There were no significant differences in clinical outcomes between the groups, although the trial was not powered to detect differences. At 30 days, the rate of major bleeding or transfusion was 3.1% in the IABC group compared with 1.7% in the standard care group. Rates of major vascular complications were 4.3% and 1.1%, respectively. There were three deaths in the IABC group and nine in the standard care group.
In an ESC press statement, Patel said that the trial did not support the use of routine IABC, adding: “Physicians should be vigilant about identifying those patients who are at risk for rapid deterioration and may benefit from counterpulsation.”
In an accompanying comment, Gjin Ndrepepa and Adnan Kastrati write that the “clear message” of the trial “is that the routine use of IABC neither reduces infarct size nor improves clinical outcome among patients with STEMI without cardiogenic shock; accordingly, use of this device should be discouraged in these patients. For patients with STEMI and cardiogenic shock, IABC remains a frequently used intervention.”