High incidence of venous thromboembolic events in lung transplant recipients

Abstract

Background: Previous studies have reported a 12% incidence of venous thromboembolic events (VTEs) in lung transplant recipients (LTRs). Characterization of risk factors for VTEs in LTRs is lacking. We identified the incidence and risk factors associated with post-transplant VTEs.

Methods: A retrospective review of 153 LTRs from 1994 to 2006 was performed. Patients were categorized by age, race, gender, weight, underlying diagnosis, procedure, ischemic time, length of stay (LOS), cardiopulmonary bypass (CPB), location and number of VTEs, mobility, immunosuppression, renal, hepatic, hematologic and coagulation profiles and nutritional status.

Results: A single VTE occurred in 29% of LTRs within the study period. Fifty-eight percent had multiple VTEs and 7% had a radiologically confirmed pulmonary embolism. Median time from transplant to first VTE was 69 days. Sixty percent of VTEs occurred within 1 year, 20% of which occurred within the first month, 19% between 2 and 5 years, and 13% at beyond 5 years post-transplant. Seventy-six percent of VTEs occurred during hospitalization, 19% during outpatient status. Forty-eight percent were of the upper extremity and 47% were of the lower extremity. Sixty-one percent of LTRs were taking cyclosporine and 39% tacrolimus. VTE and non-VTE groups were similar in age, weight, body mass index (BMI), ischemic time, procedure or underlying diagnosis precipitating the need for transplant. Univariate analysis revealed LOS and CPB as significant predictors of a single VTE (p = 0.036, hazard ratio [HR] 1.006 and p = 0.045, HR 1.91, respectively). Multivariate analysis revealed only CPB as a significant predictor (p = 0.047, HR 1.929).

Conclusions: Analysis of a cohort of LTRs for a median period of 1.5 years revealed a VTE incidence much higher than previously reported, especially within the first month after transplantation.