Author + information
- Elmir Omerovic1
Patients with STEMI are frequently pretreated with P2Y12 receptor antagonist (P2Y12) in order to increase patency of IRA and decrease the rate of ischemic events. However, there is no clear evidence from randomized clinical trials that pretreatment with P2Y12 in STEMI reduces ischemic events and improves prognosis. The aim of this study was to investigate whether pretreatment with P2Y12 improves patency of IRA at the time of primary PCI.
We used data from the SCAAR registry (Swedish Coronary Angiography and Angioplasty Registry). This database contains information about all consecutive PCI procedures that are performed in Sweden at 31 hospitals. We included all procedures between 2005 and 2015 in STEMI patients. The patients were divided into the two groups, P2Y12 pretreated and not-pretreated. We used multilevel modeling based on complete–case mixed-effects logistic regression to adjust for hierarchical database due to clustering of observations. Treated segment (IRA) was the primary observational unit while individual patients and hospitals were treated as additional levels of clustering. The following variables were used to adjust for differences in patient’s characteristics: age; gender; hypertension; hyperlipidemia; smoking status; diabetes; calendar year; prior myocardial infarction, coronary by-pass surgery and/or PCI; cardiogenic shock; severity of coronary artery disease; pretreatment with ASA, heparin; type of P2Y12 agent, clopidogrel, ticagrelor, prasugrel.
The total of 34,002 patients were included in the study of which 25,982 (76%) were pretreated with P2Y12 and 8,020 (24%) were not. Three different P2Y12 were used, clopidogrel (n=22.993, 72%), ticagrelor (n=6,657, 21%) and prasugrel (n=2,113, 7%). The number of treated segments was 64,884 of which 34,567 (53%) were occluded and 30,317 (47%) were patent prior to primary PCI. Non-patent IRA was associated with higher risk of death at 30 days (adjusted OR 1.67; 95% CI 1.47 to 1.89; P<0.000). Pretreatment with P2Y12 was not associated with higher probability for patent IRA (adjusted OR 0.95; 95% CI 0.87 to 1.04; P=0.15). We found no difference between clopidogrel, ticagrelor and prasugrel in regard to patency of IRA (P=0.13 for interaction test).
In this observational study, non-patent IRA was associated with higher risk of death at 30-days in patients with STEMI. Pretreatment with P2Y12 was not associated with improved patency of IRA.