HEROIC (Heparin Requirement in Counterpulsation)

Overview

Patients with intra-aortic balloon pumps (catheters placed in the groin connected to a pump which assists the heart by opening and closing a balloon in the aorta, thereby decreasing the work of the heart and improving blood flow to the coronary arteries) often receive intravenous (IV) heparin (a "blood thinner") to prevent circulation problems in the leg (where they are inserted). When intra-aortic balloon pumps were initially developed, the catheters were larger than the catheters used today. Due to the large size of the catheter and the material used to make the catheter, it was thought that intravenous heparin would prevent poor blood flow to the leg that contained the temporary catheter. Intravenous heparin, however, has never been proven to maintain good blood flow in these patients. The catheters used with intra-aortic balloon pumps are now smaller in size and made of a material that is less likely to produce blood clots. It is not clear that heparin is needed with intra-aortic balloon pumps. Bleeding complications associated with intra-aortic balloon pumps may be decreased if heparin is not used. In 2004, 99 patients received intra-aortic balloon pumps in the cardiac catheterization labs at William Beaumont Hospital. These patients received intravenous heparin and experienced a large number of bleeding complications (27 patients required a blood transfusion). This study will help the investigators to clarify if heparin should or should not be routinely used in patients with intra-aortic balloon pumps.

Potential patients will be identified in the cardiac catheterization lab when an intra-aortic balloon pump is placed. Patients who agree to participate in this study will be randomized (they will be selected to receive heparin or not to receive heparin with their intra-aortic balloon pump) by a process that is similar to flipping a coin. Patients will have a 50% chance of receiving heparin and a 50% chance of not receiving heparin. If a patient does not want to participate in the study, his/her cardiologist will decide if the patient will receive or not receive heparin. Intra-aortic balloon pumps have been used with and without intravenous heparin and there is no known increase in complications in patients who do not receive heparin. Risks include bleeding and possible blood clots/decreased blood flow to the leg with the catheter in both groups (due to different medical reasons). The patients in both groups will be monitored closely in the cardiac care unit while the intra-aortic balloon pump is in place to prevent and/or minimize complications.