Elderly Heart Surgery Candidate With Concerns About Transfusion

An 84-year-old man complains of worsening angina pectoris that started3 months earlier. The patient has had aortic stenosis for about 10 years. Healso has diabetes, which is controlled with oral agents.An echocardiogram shows no change in ejection velocity, size of gradient,or size of valve orifice compared with previous ultrasound studies; however,catheterization reveals significant coronary artery disease. Because hehas diabetes, valve replacement and coronary artery bypass graft (CABG)are recommended.The patient accepts the risks of surgery, but he is concerned about theblood transfusions that he is likely to require during the perioperative period.He has read and heard about the "dangerous blood supply" in the popularmedia. He is especially concerned about the possibility of contracting suchviral infections as AIDS and hepatitis C.Which of the following presents the greatest risk for this patient?A. Infection with HIV-1 or HIV-2.B. Hepatitis C virus (HCV) infection.C. West Nile virus infection.D. Hepatitis B virus (HBV) infection.E. Variant Creutzfeldt-Jakob disease.CORRECT ANSWER: D
In the last decade or so, significant progress has beenmade in reducing the well-popularized risks of transfusiontransmittedviral infections. Improved methods for screeningblood donors as well as improved testing of donatedblood have markedly altered the risk profiles of viral infectionsfrom what they were 10 to 20 years ago.The transfusion-transmitted virus that is perhapsmost feared--HIV (choice A)--has recently been estimated,based on donor screening and nucleic acid testingcurrently used in the United States, to have a transmissionrisk of 1:1,400,000 to 1:2,400,000 per blood unittransfused.¹The other well-publicized transfusion-transmittedvirus--HCV (choice B)--was epidemic in the US bloodsupply during the 1970s and 1980s, and the late hepatitis C sequela of cirrhosis is still a tremendous public healthproblem. However, there has been a marked decreasein the transmission risk of HCV, similar to that seen withHIV. Current risk estimates, based on stringent donorscreening and nucleic acid testing of donated units similarto those used for HIV, are approximately 1:1,000,000 to1:2,000,000 per blood unit transfused.¹It is also important to keep in mind that significantclinical disease takes years to develop in most patientswith HIV or HCV infection. Thus, in this 84-year-old patientwhose aortic stenosis and coronary artery disease--if untreated--will result in morbidity and mortality in farless time, the risk-benefit ratio clearly favors receivingblood now, if needed.Because of the marked reduction in HIV and HCV inthe blood supply, hepatitis B (choice D) is now the significantviral infection most frequently transmitted by transfusionin the United States. The current risk of transfusionrelated transfusionrelatedHBV infection is approximately 1:200,000 per unitof blood transfused.¹ This risk results in part from poorerscreening techniques. Detection of HBV antibodies andmeasurement of liver enzyme levels are used rather thannucleic acid testing because there is less public apprehensionabout HBV infection than there is about HIV or HCVinfection.Paradoxically, the acute morbidity and mortality associatedwith HBV infection are far more serious than thoseassociated with either HIV or HCV infection, particularlyin elderly persons.² This patient's risk of dying from HBVinfection (although quite small) is far greater than his riskof death from HIV or HCV infection.The transmission via transfusion of new infections,such as West Nile virus infection (choice C) and variantCreutzfeldt-Jakob disease (choice E), is at present onlya theoretical risk. West Nile virus infection is becoming amore frequent and troublesome public health concern;the number of cases and geographic range are increasingyearly in the United States.³ The evidence that WestNile virus infection can be transmitted by organ donationstrongly suggests the possibility--in fact, probability--that it is a blood-borne infection.³ Currently, however, noproven case of West Nile virus infection resulting fromdirect transfusion has been reported; the risk remainsconjectural, and donated units are not tested. Similarly,although prion infections, such as variant Creutzfeldt-Jakob disease, have been transmitted by donation of contaminatedtissue, such as dura or cornea, it has not beendemonstrated that transmission can occur through transfusionof blood components.Outcome of this case. The patient agreed to receivetransfusions if needed and proceeded to surgery.He received a total of 4 units of packed red blood cellsduring the perioperative period. Both the aortic valve replacementand CABG went well, and there were no postoperativecomplications. Nine months later, the patient'scardiovascular status is excellent, and his liver profileremains normal.

References:

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