The Journal of Thoracic and Cardiovascular Surgery, Vol 104, 241-247, Copyright © 1992 by The American Association for Thoracic Surgery and The Western Thoracic Surgical Association
The determinants of elevated total plasma cholesterol levels in cardiac transplant recipients administered low dose cyclosporine for immunosuppression
G Laufer, V Grablowitz, A Laczkovics, J Miholic, G Heinz, G Wollenek, W Schreiner, J Wolfram and E Wolner
Second Department of Surgery, University of Vienna, Austria.
Elevated total plasma cholesterol level is a frequent finding after cardiac
transplantation. To identify risk factors for the development of
hypercholesterolemic states, we applied multivariate statistics in a
logistic and linear manner. Six-month posttransplantation levels of total
plasma cholesterol in 57 adult heart recipients were available for
analysis. Maintenance immunosuppression was carried out with either
cyclosporine and azathioprine or both agents plus low-dose steroids. Total
plasma cholesterol levels were dichotomized for the logistic analysis (1)
by the age- and sex-matched 75th and 90th percentiles of a reference
population according to National Institutes of Health treatment guidelines
and (2) by the cut point 250 mg/dl. Twelve potential risk factors were
evaluated as covariates: recipient age, body weight after 6 months, body
weight gain over 6 months, body mass index after 6 months, body mass index
gain over 6 months, current cyclosporine dosage, trough level of
cyclosporine in whole blood according to high-performance liquid
chromatography after 6 months, cumulative cyclosporine dosage over 6
months, serum bilirubin, type of original cardiac disease, maintenance
steroids, and steroid bolus treatment. Multivariate logistic regression
yielded the type of original cardiac disease as a significant predictor of
posttransplantation hypercholesterolemia exceeding the 90th percentile (p =
0.019) and of hypercholesterolemia exceeding 250 mg/dl (p = 0.032).
Maintenance steroids were identified as a second significant cofactor (p =
0.069) for total plasma cholesterol levels exceeding 250 mg/dl. Multiple
linear regression again revealed the type of original cardiac disease and
maintenance steroids as significant predictors by p values of 0.005 and
0.013, respectively. Patients with coronary artery disease as the original
cardiac pathology and low-dose maintenance steroids had the greatest risk
for the development of elevated total plasma cholesterol levels after
cardiac transplantation. However, the overall predictive quality of the
linear model was limited (multiple r value 0.43), which indicates that
other variables besides the tested ones attributed to elevated total plasma
cholesterol levels. These results confirm the adverse role of maintenance
steroids on posttransplantation hypercholesterolemia and demonstrate the
type of original cardiac disease as the most important risk factor. They
suggest that abnormalities of lipoprotein metabolism and dietary factors
continue to affect total plasma cholesterol levels after cardiac
transplantation.
