Study objectives: Clopidogrel is often prescribed for primary or secondary prevention of cardiovascular disease and has been associated with unwanted bleeding events. After having shown that transbronchial biopsy can safely be performed in pigs receiving clopidogrel, we sought to determine whether routine clopidogrel use increases the risk of bleeding after transbronchial lung biopsy in humans.
Design: Prospective cohort study.
Patients and interventions: Data were collected on 604 patients without underlying coagulation problems who underwent transbronchial lung biopsy over 13 months. Clopidogrel was not discontinued before biopsy in patients who were using it. Transbronchial biopsies were performed, and the incidence of bleeding and other complications among patients receiving clopidogrel was compared with that of other patients.
Results: The study was stopped early because the bleeding rate in the clopidogrel-only group (n = 18) was excessive (89% [16 of 18 patients] vs 3.4% [20 of 574 control subjects; p > 0.001] and also in the group receiving clopidogrel and aspirin (100% [12 of 12 patients] vs 3.4% among control subjects [p > 0.001]. Bleeding rates were significantly higher in the clopidogrel group for each degree of bleeding severity: mild (27% vs 1.5%), moderate (34% vs 1.5%), and severe (27% vs 0.3%; p > 0.001 for all comparisons). All 12 patients receiving both aspirin and clopidogrel had bleeding: moderate in 6 patients and severe in 6 patients. All bleeding was controlled by endoscopic means. There were no fatalities or need for blood transfusions in the patients enrolled in the trial.
Conclusions: Clopidogrel use greatly increases the risk of bleeding after transbronchial lung biopsy in humans and therefore should be discontinued before bronchoscopy with biopsies. Aspirin exacerbates the effect of clopidogrel on bleeding.