Coronary Artery Bypass Surgery in a Patient with Analbuminemia

Abstract

Congenital analbuminemia is a rare autosomal recessive disorder characterized by the absence of serum albumin, or by its presence in very low concentrations. Up to now, only 43 cases have been reported. There is little information about analbuminemia, and no operation on an analbuminemic patient has been reported. This, we believe, is the 1st report of an operation on an analbuminemic patient for coronary artery disease in which the perioperative experience is presented.

Congenital analbuminemia is a rare autosomal recessive disorder characterized by the absence of serum albumin, or its presence in very low concentrations. The diagnosis is confirmed by plasma protein electrophoresis that depicts an absence of an albumin band. Up to now, only 43 cases have been reported.¹ Herein, we report the outcome of open heart surgery on an analbuminemic patient from Turkey whose analbuminemia was reported by Galliano and colleagues in 2002, before the surgery took place.² The patient underwent open heart surgery 7 years after his analbuminemia was diagnosed. This is the 1st report of surgery on an analbuminemic patient for coronary artery disease, in which perioperative experience is presented.

Case Report

In January 2009, a 37-year-old man with known congenital analbuminemia was admitted to our hospital with acute coronary syndrome. Coronary angiography revealed 3-vessel coronary artery disease. A coronary artery bypass operation was planned.

Analbuminemia had been diagnosed 7 years before, in a university hospital. In that hospital's nephrology clinic (where the patient was undergoing follow-up), protein electrophoresis and genetic evaluation were performed (Fig. 1). His family had a history of coronary artery disease and hypercholesterolemia. In preoperative evaluation, the patient was found to have hypercholesterolemia despite statin treatment. The total cholesterol and low-density-lipoprotein cholesterol levels were 246 and 162 mg/dL, respectively. The patient had a history of bilateral, lower-extremity, deep venous thrombosis (which had occurred 3 years earlier), but he was on no treatment except for pressure stockings. Biochemical analysis revealed hypercholesterolemia and hypoproteinemia. His renal function results were almost normal. The creatinine and blood urea nitrogen levels were 0.92 and 34 mg/dL, respectively.

Fig. 1 Densitometric scan of plasma protein electrophoresis of the patient. The bracketed space marked by an asterisk indicates the range of difference between the albumin band of a healthy individual and the albumin band of our analbuminemic patient. The uppermost bracket indicates the lowest level of normal. Alb = albumin band

We consulted his university nephrology clinic in search of any history of albumin-depleting nephropathies that might be a predisposing factor for albumin deficiency. They confirmed that he was solely an analbuminemia patient, and they advised perioperative albumin treatment. Therefore, we administered albumin, and his plasma albumin level rose from 0.5 to 3 g/dL. We transfused 1,100 cc of albumin at 100 mL/d for 11 preoperative days. The patient underwent on-pump coronary artery bypass grafting with the aid of moderate hypothermia and cardioplegia with an isothermic blood solution. We bypassed 3 vessels, using left and right internal thoracic artery grafts and a saphenous vein graft. The patient stayed in the intensive care unit for 2 days. During postoperative recovery, albumin treatment was continued in order to keep the plasma albumin level above 3 g/dL. He was discharged from the hospital on the 9th postoperative day. The patient remained in good condition when last seen, at his 1st- and 3rd-month follow-up appointments.

Discussion

Analbuminemia is caused by a variety of mutations in the albumin gene and is exhibited only by subjects who are homozygous for the defect. The incidence of analbuminemia is estimated to be lower than 1 in 1 million births.³ The main compensatory mechanism is an increase in the synthesis of nonalbumin proteins, which take over the functions of albumin.

The clinical symptoms of analbuminemia are mild, but the condition can have important complications. For example, ions and hormones can show altered protein-binding. Albumin-binding drugs should be used with caution, although this caveat is debatable. Frohlich and colleagues⁴ reported the case of a child in whom the unbound fraction of albumin-binding drugs (warfarin and diazepam) was approximately 10-fold normal. In our patient, we did not observe any event related to electrolyte or hormone changes, nor did we observe any change in the pharmacokinetics of the drugs in the perioperative term.

Considering the severe hypercholesterolemia seen in most cases of analbuminemia, the major concern is whether patients are at risk of atherosclerosis-related complications. Some investigators believe that the condition does not lead to atherosclerosis, whereas others maintain that this risk cannot be excluded because follow-up of analbuminemic patients has been insufficient. Our patient had high levels of blood cholesterol despite statin treatment, but this also could be a familial trait, insofar as his relatives were known to be hypercholesterolemic. Koot and colleagues⁵ advocated the use of statins, but Burgess and Marais⁶ reported 2 cases in which analbuminemic patients treated with statins experienced a rise in serum creatine kinase levels without clinical symptoms; the authors related this increase to the altered pharmacokinetics observed in these patients. Although the link between hypercholesterolemia and atherosclerosis is unclear, we believe that postoperative statin treatment is worth the risk. No complication related to statin treatment was observed in our follow-up of this patient.

Theoretically, the increased serum coagulation factors and the deficiency of some serum proteins—such as protein C, protein S, and antithrombin III—might predispose analbuminemic patients to thrombotic events. There are, in fact, 2 reports of cases^7,8 involving thrombotic events. In our patient, we lack evidence of any predisposing factor, because no relevant study was performed in our clinic or in the university clinic. We administered low-molecular-weight heparin both before and after surgery, and we prescribed warfarin after discharge and recommended lifelong treatment with the drug.

We preferred on-pump surgery to a beating-heart procedure, because our patient's left anterior descending coronary artery was of small caliber and followed an intramyocardial course. Heparinization, hemodilution, and hypothermia are components of on-pump open heart surgery, and each, in the absence of albumin, can lead to catastrophic changes in the operative course. Beating-heart surgery surely is more physiologic than is conventional on-pump surgery and might be more appropriate for analbuminemic patients.

Conclusion

This, to the best of our knowledge, is the 1st reported case of an analbuminemic patient who has undergone open heart surgery. We tried to devise solutions to particular problems that we thought could complicate the procedure and the postoperative outcome. The preoperative albumin treatment might seem irrational; however, when the pros and the cons were taken into account, we decided that the treatment could be beneficial in stabilizing the changes in osmotic state and the buffering mechanisms of on-pump surgery, despite some unimportant side effects. We advocate using an albumin treatment perioperatively to keep the serum albumin level above 3 g/dL in these patients, until the role of albumin treatment is clarified by further investigation.