Jehovah's Witnesses, whose religious beliefs prohibit them from having blood transfusions, had fewer complications and shorter hospital stays than other heart patients who had transfusions for surgery over a 28-year period at Cleveland Clinic, a new study concludes.

In fact, Jehovah's Witnesses spent less time in hospital and in intensive care, on average, and weren't as likely to need a further operation as a result of bleeding problems compared to other patients, according to the study released Monday in the Archives of Internal Medicine.

"Current extreme blood management strategies do not appear to place patients at heightened risk for reduced long-term survival," says the study, which was led by Dr. Gregory Pattakos.

During heart surgery, patients are sometimes given a transfusion of red blood cells to prevent anemia. For Jehovah's Witnesses, the strategy may focus on giving them certain vitamins and iron so their red blood cell counts don't get too low during a procedure.

Slightly fewer Witnesses died in hospital

For the Cleveland Clinic research, 87,775 cardiac surgery patients were identified as having had heart surgery between 1983 and 2011. Of those, 322 were Jehovah's Witnesses. Of the non-Jehovah's Witnesses, 48,986 (56 per cent) received blood transfusions and 38,467 (44 per cent) did not.

The researchers compared the 322 Jehovah's Witnesses to an equal number of patients "who were similar in most ways," but who did receive transfusions. Most of the patients had bypass surgeries.

'An important limitation of the study is that Witnesses who undergo cardiac surgery are likely a healthier subgroup of Witnesses because those who are believed by their surgeons to require blood transfusion to survive cardiac surgery presumably never go to the operating room.'—Dr. Victor A. Ferraris, University of Kentucky Chandler Medical Center

The researchers found a "similar" number of patients — 10 Jehovah's Witnesses and 14 in the comparison group — died in hospital. One Jehovah's Witness had a heart attack (myocardial infarction) during a procedure, compared to nine people who had blood transfusions.

The study also found that among the fewer complications, the Jehovah's Witnesses patients, compared to the non-Witnesses, had fewer incidences of:

  • Myocardial infarction (0.31 per cent versus 2.8 per cent).
  • Additional operations for bleeding (3.7 per cent versus 7.1 per cent).
  • Prolonged ventilation (six per cent versus 16 per cent).

'Conservative' use of transfusions may be beneficial

The researchers didn't give reasons for the different patient outcomes.

But in a commentary accompanying the study, Dr. Victor A. Ferraris of the University of Kentucky Chandler Medical Center in Lexington said: "An important limitation of the study is that Witnesses who undergo cardiac surgery are likely a healthier subgroup of Witnesses because those who are believed by their surgeons to require blood transfusion to survive cardiac surgery presumably never go to the operating room."

However, Ferraris added, the finding that Jehovah's Witnesses who didn't receive transfusions did as well as or better than patients who received transfusions "raises questions about whether more patients might benefit from surgical strategies that minimize transfusion of blood products."

He also said the Cleveland Clinic findings add to previous research that suggests "more conservative use of blood transfusions" would be in the best interests of all patients.