Background: Cyclosporine is the main drug used for immunosupression among cardiac transplant patients and its blood levels can be measured at 0 and 2 hours after oral intake (C₀ and C₂ levels). Among kidney and liver transplants there are some data suggesting that C₂ measurment is the most effective way of monitoring cyclosporine levels. However data about C₂ monitorization and cardiac transplantation is limited.

Methods: During the period between May 1998 and May 2002, 18 patients underwent orthotophic heart transplantation and all patients recieved triple immunosupressive regiment (cyclosporine,azathiprine and corticosteroid) postoperatively. Cyclosorine levels were monitored with C₀ measurements for the first 9 patients (Group I). C₀ and C₂ measurements were used for the last 9 patients (Group II). C₀ and C₂ drug levels were kept within 250-300 ng/ml and 1100-1300 ng/ml respectfully for the first 3 month then target levels were gradually reduced.

Results: Grade 1A to 3A acute rejection episodes were detected on endomyocardial biopsies among 6 patients (66%) monitored only with C₀ measurements. In contrast only one grade 1A rejection episode was detected among patients monitored with both C₀ and C₂ measurements. However in this group there were patients who had normal C₀ but elevated C₂ levels in respect to the targeted values and these patients had serious cyclosporine side effects (44%) and infections (22%).

Conclusions: C₂ monitorization for cyclosporine serum levels measurement among heart transplant recipients although provides ideal values for blood level arrengements, needs larger sample size studies in order to identify best target values.

Keywords : Heart transplantation, cyclosporine, immunosupression, endomyocardial biopsy