Coronary syndromes following aspirin withdrawal - A special risk for late stent thrombosis

OBJECTIVES We sought to determine whether aspirin withdrawal is an encountered situation in coronary disease patients who relapsed. BACKGROUND Despite the recognized benefits of aspirin in coronary disease, and because of the threat of bleeding or poor compliance, aspirin intake is sometimes stopped. It is not known whether withdrawal of aspirin can be harmful in coronary-disease patients. METHODS Between September 1999 and April 2002, a total of 1,236 patients hospitalized for acute coronary syndrome (ACS) were questioned in order to determine whether aspirin intake had been interrupted. RESULTS Fifty-one of these ACSs occurred within 1 month after aspirin withdrawal. This represents 4.1% of all coronary events but 13.3% of recurrences. Among those patients who relapsed, the incidence of ST-segment elevation ACS was higher in those who stopped aspirin when compared to the 332 patients who did not stop aspirin (39% vs. 18%; p = 0.001). Ten (20%) cases involved a thrombosis of an uncoated stent implanted on average 15.5 +/- 6.5 months previously. Mean delay between aspirin withdrawal and the acute coronary event was 10 +/- 1.9 days. Reasons for aspirin withdrawal included minor surgery in 7 cases, fibroscopy in 8 cases, dental treatment in 13 cases, bleeding in 3 cases, and patient non-compliance in 20 cases. CONCLUSIONS Our results support the hypothesis that aspirin withdrawal in coronary patients may represent a real risk for the occurrence of a new coronary event. Many cases involved late uncoated-stent thrombosis. Assessment of the exact incidence of coronary recurrences after aspirin withdrawal will need prospective studies. (C) 2005 by the American College of Cardiology Foundation.