Bloodless Heart Surgery Risk Overstated

http://www.medpagetoday.com/Cardiology/AcuteCoronarySyndrome/33600

 

Patients who refuse blood transfusions during cardiac surgery may not necessarily be at an increased risk for surgical complications or long-term mortality, researchers found.

 

Compared with patients who had transfusions, Jehovah's Witnesses -- a religious group that forbids blood sharing -- had significantly lower rates of myocardial infarction, additional operations for bleeding, and prolonged ventilation, as well as shorter hospital stays, Colleen Koch, MD, of the Cleveland Clinic, and colleagues reported online in the Archives of Internal Medicine.

 

They also had significantly better 1-year survival (P=0.007) and comparable 20-year survival, they reported.

 

"Thus, current extreme blood management strategies do not appear to place patients at heightened risk for reduced long-term survival," the researchers wrote.

 

Jehovah's Witnesses believe that the Bible prohibits ingesting blood, which makes blood transfusions or donation off-limits. Instead, the group encourages the use of a number of blood conservation practices, including preoperative erythropoietin, iron, and B-complex vitamins, as well as liberal postoperative use of additional operations for bleeding.

 

However, some blood conservation practices have been associated with morbidity. For instance, the routine use of erythropoietin may increase the risk of thromboembolic complications.

 

Also, comparisons of long-term survival with blood conservation are lacking, the researchers said.

 

So they assessed 322 Jehovah's Witness patients, all of whom refused blood transfusions, and matched them with an additional 322 patients who'd received blood during heart surgery at their clinic between Jan. 1, 1983 and Jan. 1, 2011.

 

The main outcomes were postoperative morbidity, in-hospital mortality, and long-term survival.

 

After propensity matching, the researchers found that both groups had similar risks of in-hospital mortality, stroke, atrial fibrillation, and renal failure, but those in the study group had fewer of the following acute complications:

MI: 0.31% versus 2.8% (P=0.01)

Additional operations for bleeding: 3.7% versus 7.1% (P=0.03)

Prolonged ventilation: 6% versus 16% (P<0.001)

 

 

Witnesses also had shorter stays, both in the intensive care unit and in the hospital in general (P<0.001 for both), as well as better 1-year survival (95% versus 89%, P=0.007).

 

Both groups, however, had similar 20-year survival (34% and 32%).

 

Koch and colleagues concluded that refusing blood transfusions after cardiac surgery likely won't put patients at increased risk for surgical complications or long-term mortality.

 

They noted that the study was limited because it couldn't be done as a randomized trial, and by the potential for selection bias. Witnesses treated at the center may have been healthier because those who would have been deemed to need blood transfusions to survive the surgery probably wouldn't have made it to the operating room, they said.

 

In an accompanying editorial, Victor Ferraris, MD, PhD, of the University of Kentucky in Lexington, noted that more observational evidence has been suggesting that there could be some harm from receiving blood transfusions during surgery, and that the findings "add to the increasing data that suggest more conservative use of blood transfusions would be in our patients' interest, in both Witnesses and non-Witnesses."