Timely and appropriate use of antiplatelet and anticoagulant therapies has been shown to improve outcomes among ST-segment elevation myocardial infarction (STEMI) patients but has not been well described in patients transferred for primary percutaneous coronary intervention (PCI).Methods
We examined 16,801 (26%) transfer and 47,329 direct-arrival STEMI patients treated with primary PCI at 441 Acute Coronary Treatment and Intervention Outcomes Network Registry–Get With The Guidelines hospitals. Medication use was compared between transfer and direct-arrival patients to determine if these therapies were delayed or dosed in excess.Results
Although transfer patients were more likely to receive antiplatelet and anticoagulant therapies before catheterization, they had longer delays to initiation of heparin (35 vs 25 minutes), clopidogrel (119 vs 84 minutes), and glycoprotein IIb/IIIa inhibitor (107 vs 60 minutes, P < .0001 for both). Administration of low-molecular-weight heparin and glycoprotein IIb/IIIa inhibitor at the STEMI-referring hospital was associated with longer delays to reperfusion compared with deferred administration at the STEMI-receiving hospital, whereas early use of unfractionated heparin was not. Among treated patients, those transferred were more likely to receive excess heparin dosing (adjusted odds ratio [OR] 1.28 [95% CI 1.04-1.58] for unfractionated heparin, adjusted OR 1.54 [95% CI 1.09-2.18] for low-molecular-weight heparin) and are associated with higher risks of major bleeding complications (adjusted OR 1.10, 95% CI 1.03-1.17).Conclusions
ST-segment elevation myocardial infarction patients transferred for primary PCI in community practice are at risk for delayed and excessively dosed antithrombotic therapy, highlighting the need for continued quality improvement to maximize the appropriate use of these important adjunctive therapies.