Abstract 4610: Stent Thrombosis Exhibits a Diurnal Variation With a Higher Incidence of Morning Events
Background: A morning peak of development of ACS is well described and may be due to increased platelet activity upon arising. It is unknown whether stent thrombosis (ST) also has a circadian pattern. TRITON-TIMI 38 allowed us to evaluate if a diurnal variation in ST occurs, and if more robust anti-platelet therapy with prasugrel (vs clopidogrel) can attenuate a morning excess.
Methods: Patients from TRITON-TIMI 38 (N=13,608) with adjudicated ST classified per the Academic Research Consortium definitions of definite (N=135) and probable (N=26) with accurate events times, were grouped into 8-hr intervals by time of onset: morning (6AM-2PM), evening (2PM-10PM), overnight (10PM-6AM).
Results: A morning peak in definite/probable ST occurred with 52% of events between 6AM-2PM (rates per 1000 patients treated of 6.54, 3.89, and 2.10 for morning, evening, and overnight intervals, respectively, P<0.001). A sensitivity analysis excluding peri-procedural acute-ST (<24hrs post index PCI) resulted in similar findings(5.22, 2.49, 1.79, P<0.001). Both treatment groups had significant variation from a uniform distribution (clopidogrel P<0.001, prasugrel P=0.020, Fig 1⇓) with a morning excess of ST. Patients on clopidogrel had a particularly pronounced morning incidence (9.65 per 1000 patients, Fig 1⇓).
Conclusions: In TRITON-TIMI 38 stent thrombosis exhibited a significant diurnal variation with a morning peak similar to that seen with onset of other acute coronary syndromes. Prasugrel reduced the number of ST at all times of day, with the greatest absolute reduction (6.22 per 1000 patients) of morning events when platelet activity is know to be highest.