Patients from a real-world registry who received primary PCI with stenting had a 30-day stent thrombosis rate of less than 1%, regardless of what type of antithrombotic therapy was used, according to data presented at EuroPCR.
However, patients who had stent thrombosis within the first 30 days were more likely to die within 1 year compared with those who did not, and there was a numerically higher rate of all-cause mortality at 1 year for those who developed stent thrombosis between 2 and 30 days compared with those who developed it within 24 hours, researchers reported.
“What is new, to my knowledge, is the relationship between stent thrombosis timing and mortality at 1 year,” Per Grimfjard, MD, from Västerås Hospital, Uppsala University, Sweden, said in a press release. “A possible explanation is that a stent thrombosis that happens once the patient has left the hospital is likely to cause a more substantial infarction, the reason being longer delay from symptoms to revascularization.”
Grimfjard and colleagues conducted a prospective observational cohort study using data from the Swedish Coronary Angiography and Angioplasty Register, part of the nationwide SWEDEHEART registry. They analyzed all patients who underwent primary PCI and received a stent in Sweden between January 2007 and July 2014, stratified by antithrombotic therapy: bivalirudin (Angiomax, The Medicines Company; n = 16,860); heparin alone (n = 3,182); or glycoprotein IIb/IIIa inhibitors, usually combined with heparin (n = 11,216).
The primary outcome was definite stent thrombosis within 30 days of PCI. A secondary outcome was all-cause mortality.
All three groups had incidence of early stent thrombosis of less than 1% (bivalirudin group, 0.84%; heparin group, 0.94%; glycoprotein IIb/IIIa group, 0.83%), according to Grimfjard.
Crude incidence rates of stent thrombosis within 24 hours were similar between the groups (bivalirudin group, 0.33%; heparin group, 0.28%; glycoprotein IIb/IIIa group, 0.21%), as were crude incidence rates of stent thrombosis between 2 and 30 days (bivalirudin group, 0.53%; heparin group, 0.68%; glycoprotein IIb/IIIa group, 0.64%), he said.
The 1-year all-cause mortality rate was 20.7% for those who had early stent thrombosis vs. 9.1% for those who did not (P < .001), he said.
He noted that there was numerically higher all-cause mortality at 1 year for those who had stent thrombosis at 2 to 30 days (23.03%) compared with those who had it within 24 hours (16.05%; P = .204).
Grimfjard said in the release that the results of the present study do not provide any direction for choice of antithrombotic therapy for patients undergoing primary PCI, but an ongoing trial might. That study, SWEDEHEART-Validate, is a 6,000-patient, registry-based, randomized clinical trial comparing heparin alone vs. bivalirudin plus optional low-dose heparin in patients with STEMI and non-STEMI undergoing PCI, according to the release. – by Erik Swain
Grimfjard P, et al. Hot Line: Antithrombotic Strategies. Presented at: EuroPCR, May 19-22, 2015; Paris.
Disclosure: Grimfjard reports no relevant financial disclosures.