Society of Cardiology Congress 2011
Infarct size as measured by MRI does not reduce when
intra-aortic balloon pump counterpulsation is used before percutaneous coronary
intervention in patients with STEMI, new study results indicated.
In the CRISP AMI trial, patients with acute STEMI
without shock were randomly assigned into two groups. One group included 161
patients who received intra-aortic balloon counterpulsation (IABC), and the
second group included 176 patients who received primary PCI without IABC
support (SOC). Patients included had chest pain onset within 6 hours and
planned primary PCI. Researchers had an infarct size measured by cardiac MRI at
3 to 5 days post-PCI as the primary efficacy endpoint, and a secondary clinical
endpoint was a composite of major adverse clinical events that included death,
reinfarction and HF at 6 months. Results of the trial were presented at the
European Society of Cardiology Congress 2011 in Paris.
Animal studies had suggested that inserting a
balloon pump before opening the vessel would reduce the hearts
workload and, by doing so, could potentially reduce size, Manesh
Patel, MD, of the Duke Clinical Research Institute at Duke University, said
in a press release. However, having tested this observation in humans, we
did not show similar results.
IABC and SOC groups did not have significantly different
mean infarct sizes. The percentage of left ventricle affected in the IABC group
was 42.1% vs. 37.5% in the SOC group. Major bleeding or transfusion occurred in
3.1% of IABC patients and 1.7% of SOC patients by 30 days, and major vascular
complications occurred in 4.3% of IABC patients and 1.1% of SOC patients. Death
occurred by 6 months in 1.9% of IABC patients and 5.2% of SOC patients.
Overall, not only did the study no meet its primary endpoint, it was also not
powered to draw significant conclusions on clinical events.
While this trial shows that the routine use of
IABC cannot be recommended in
STEMI, physicians should be vigilant about identifying those
patients who are at risk for rapid deterioration and may benefit from
counterpulsation, Patel said.
For more information:
Disclosure: Dr. Patel reports no relevant financial disclosures.
Potential benefits of IABC are increase of coronary blood flow, increase
of diastolic BP, increase of collateral circulation, increase of organ
perfusion, decrease of afterload and increase of CI. [However,] IABC is not for
all-comers with STEMI, and patients who might benefit from IABP still have to
Kurt Huber, MD
Department of Medicine,
Cardiology and Emergency Medicine
Wilhelminen Hospital, Austria