Clopidogrel resistance after renal transplantation.

Background: Leading causes of mortality and morbidity after kidney transplantation are cardiovascular diseases. One of the fundamentals of their prevention is the inhibition of platelet aggregation. Resistance to anti-platelet agents is a well-established phenomenon; however, its causes are yet to be clarified. Patients and Methods: Forty post-transplant patients, who received 75 mg clopidogrel q.d. as a prophylactic measure, were examined using optical aggregometry. Subsequently, logistic regression analysis was performed with 24 variables in order to expose possible causes of resistance. Results: Sixty percent of patients (24) were resistant to clopidogrel therapy; effective thrombocyte inhibition could only be shown in 40% of them (16). Significant correspondence between resistance and variables could not be found. Conclusion: Clopidogrel resistance is expected to occur on a large scale in patients who underwent kidney transplant surgery. Thus, a key component of preventive therapy, which stresses the importance of discovering the cause of resistance so as to decrease mortality rates, is missing.