Abstract 4486: Stent Thrombosis After Drug-Eluting Stent Implantation: Incidence, Timing and Relation to Discontinuation of Clopidogrel Therapy Over a 4-Year Period
To assess the incidence, timing and relation of drug-eluting stent thrombosis (ST) to discontinuation of clopidogrel therapy. This prospective observational cohort study includes 6816 consecutive patients that underwent a successful drug-eluting stent (DES) implantation between July 2002 through December 2006 in 2 tertiary, high-volume percutaneous coronary intervention (PCI) centers in Germany. The primary end point was definite ST (ARC definition). During 4-year follow-up, 4.2% of the patient population incurred a myocardial infarction (MI), 8.6% had died and 3.1% had experienced a bleeding complication. Definite ST was observed in 73 patients, corresponding to a cumulative incidence of 1.2% at 4 years. Cumulative incidence of ST was 0.5% at 30 days and 0.8% at 1 year. In comparison to patients without ST, patients with ST carried a higher risk of MI (93% versus 3%; OR 48.5 [41.3 to 57.1]) and death (42% versus 8%; OR 5.2 [3.6 to 7.6]). Figure 1⇓ shows the number of patients with ST in each time interval from discontinuation of clopidogrel therapy. Figure 2⇓ depicts the cumulative incidence of ST in patients who were on clopidogrel therapy and in those who discontinued clopidogrel. The 4-year incidence of ST after DES implantation is low in high-volume PCI centers. A relevant number of ST occur early after discontinuation of clopidogrel therapy. The dependence of ST on discontinuation of clopidogrel therapy is evident during the first 6 months but not thereafter.