October 13th, 2010

Transfusions and Cardiac Surgery: “A Major Concern”

One new study in JAMA demonstrates very wide differences among hospitals in the use of transfusions during cardiac surgery. A second study finds no differences in outcome based on transfusions. Two editorialists write that “continued inappropriate transfusions among hospitals is a major concern.”

Bennett-Guerro and colleagues analyzed the Society of Thoracic Surgeons Adult Cardiac Surgery Database to assess the rate of perioperative blood transfusions in over 100,000 patients who underwent CABG in 2008. The transfusion rate across CABG sites ranged from 7.8% to 92.8% for red blood cells (RBCs) and from 0% to 97.5% for fresh-frozen plasma. Although geographic location, academic status, and hospital volume were all significant factors, these three characteristics accounted for only a small (11.1%) portion of the variation in risk-adjusted RBC usage. The investigators write that “to our knowledge, there has never been a large randomized trial of the safety and efficacy of blood transfusion in cardiac surgery; therefore, some of the variability we observed may be due to honest differences between clinicians in the perceived benefits and risks of transfusion.”

In an attempt to shed some light on the topic, Hajjar and colleagues performed the propspective Transfusion Requirements After Cardiac Surgery (TRACS) clinical trial. They randomized 502 patients at a single university hospital in Brazil to either a liberal strategy of blood transfusion or a restrictive strategy (hematocrit goal of > 30% or >24%). Some 78% of patients in the liberal strategy group received a transfusion, compared with 47% in the restrictive-strategy group. The composite endpoint of 30-day mortality, cardiogenic shock, acute respiratory distress syndrome, or acute injury requiring dialysis or hemofiltration did not differ significantly between the two groups (10% vs. 11%, P=0.85).

In an accompanying editorial, Aryeh Shander and Lawrence Goodnough observe that Society of Thoracic Surgeons ratings of cardiac surgery programs do not include RBC transfusions as a quality indicator and suggest that “it may be time for patient blood management to gain status as a performance indicator by accreditation agencies such as the Joint Commission or as a quality indicator by professional organizations.” They conclude:

“When evaluating a hemoglobin level, treating physicians must resist the temptation to ‘first do something’ and temper this temptation with a philosophy of ‘first do no harm’ to achieve the optimal balance of providing the best risk-benefit and cost-effective outcomes of transfusion therapy for patients.”

5 Responses to “Transfusions and Cardiac Surgery: “A Major Concern””

  1. Robin Motz, M.D., Ph.D. says:

    But don’t you recall a study in NEJM about 10 years ago that used data so show that Boston had 5 times as many CABG’s per capita as did New Haven, and New Haven 5 times as many cholecystectomies as Boston, and no one could determine which (if any) city had too many or too few operations, and of what.

  2. The transfusion of red blood cells to correct anemia has been described as one of the least scientific practices in medicine today. The TRICC trial (published in the NEJM in 1999) clearly showed that a restrictive transfusion strategy (transfusing only if Hemoglobin falls below 7 g/dl) was as good as, and possibly better, than a liberal transfusion strategy (transfusing when hemoglobin falls below 10 g/dl). There are multiple papers supporting a restrictive approach to transfusion in patients undergoing cardiothoracic surgery. However there has not been any clear recommendation on the use of transfusion in patients with acute coronary syndrome (ACS), although Rao et al (JAMA 2004) showed that transfusion during ACS is associated with increased mortality. It is noteworthy that the ACC/AHA guidelines on management of STEMI and NSTEMI make no mention of transfusion, but transfusion to maintain hemoglobin levels at or above 10 g/dl seems to be standard practice among cardiologists at my institution. I would really love to hear from other members of this forum, especially cardiologists, on what factors guide their decision to transfuse in patients with ACS.

    Competing interests pertaining specifically to this post, comment, or both:
    No conflicts of interest.

  3. Robin Motz, M.D., Ph.D. says:

    Unfortunately, many of our practices are based on common sense predictions of what human physiology should require, rather than on clinical studies. Let’s remember that when (most of us) were residents, we were taught that one of the worst medications to give a patient in heart failure was a beta-blocker. And we still don’t have any good evidence as to the proper interval between stress tests after PTCA or CABG, but rather either follow a “gut” instinct or the time spacing an insurance company will pay for. And without the studies done at U Texas, Galveston, who would have dreamed that one of the treatments to prevent Ca++ kidney stones is to INcrease the amount of calcium in the diet?

  4. Although in my training I was instructed to maintain a hemoglobin of 10 g/dl in ACS patients, I don’t currently transfuse to achieve a certain hemoglobin. The clinical status of the patient dictates whether they are allowed to have a lower hemoglobin (i.e., 8-10 g/dl) or get transfused

  5. Our transfusion committee reviews RBC transfusions in patients with ACS when the hemoglobin is over 8 g/dl. If chart review reveals that the patient was hemodynamically stable, the rationale for transfusion is questioned. Could this topic be submitted to “the expert is in” for comment?

    Competing interests pertaining specifically to this post, comment, or both: