Clinical InvestigationLow real-world early stent thrombosis rates in ST-elevation myocardial infarction patients and the use of bivalirudin, heparin alone or glycoprotein IIb/IIIa inhibitor treatment: A nationwide Swedish registry report

BackgroundIn recent studies of primary percutaneous coronary intervention (PCI), bivalirudin compared with heparin has been associated with increased risk of stent thrombosis (ST). Our aim was to describe incidence and outcome of definite, early ST in a large contemporary primary PCI population divided in antithrombotic therapy subgroups.Methods and ResultsA prospective, observational cohort study of all 31,258 ST-elevation myocardial infarction patients who received a stent in Sweden from January 2007 to July 2014 in the SWEDEHEART registry was conducted. Patients were divided into 3 groups: bivalirudin, heparin alone, or glycoprotein IIb/IIIa inhibitor treated. Primary outcome measure was incidence of definite early ST (within 30 days of PCI). Secondary outcomes included all-cause mortality. Incidence of early ST was low, regardless of bivalirudin, heparin alone, or glycoprotein IIb/IIIa inhibitor treatment (0.84%, 0.94%, and 0.83%, respectively). All-cause mortality at 1 year was 20.7% for all ST patients (n = 265), compared with 9.1% in those without ST (n = 31,286; P < .001). Patients with ST days 2-30 had numerically higher all-cause mortality at 1 year compared with patients with ST days 0-1 (23% vs 16%, P = .20).ConclusionIn this real-world observational study of 31,258 ST-elevation myocardial infarction patients, the incidence of early ST was low, regardless of antithrombotic treatment strategy. Early ST was associated with increased mortality. Numerically higher all-cause mortality at 1 year was noted with ST days 2-30 compared with ST days 0-1 post-PCI.