Key Points:
- The RIGHT trial assessed the benefit of post-procedural anticoagulation (PPA) after primary percutaneous coronary intervention (PCI) in ST-segment elevation myocardial infarction (STEMI) patients.
- The trial found that overall, PPA did not result in a significant reduction in adverse outcomes compared to placebo in a low-to-intermediate risk population.
- There was a significant interaction between the type of anticoagulant used and the primary endpoint, with enoxaparin showing potential benefit while unfractionated heparin and bivalirudin did not.
The RIGHT trial was an investigator-initiated, multicenter, randomized, double blind study that sought to shed light on the role of post-procedural anticoagulation (PPA) in patients who undergo primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI). The trial’s primary objective was to ascertain whether routine use of low-dose PPA (enoxaparin, unfractionated heparin, or bivalirudin) could be superior to a placebo after the procedure in contemporary practice.
The trial was conducted 53 different locations across China. Before starting the trial, each of these locations chose one of three PPA regimens: enoxaparin 40 mg administered once daily under the skin, unfractionated heparin at a rate of 10 units/kg/hour, or bivalirudin at a rate of 0.2 mg/kg/hour via IV infusion. The patients were then assigned randomly in a 1:1 manner to either receive a low-dose PPA or receive a placebo that matched the PPA, and this treatment continued for a minimum of 48 hours.
The primary efficacy objective was defined as superiority of PPA to reduce the primary efficacy endpoint of all-cause death, non-fatal myocardial infarction, non-fatal stroke, definite stent thrombosis, or urgent revascularization of any vessel within 30 days. The key secondary objective was to evaluate the effect of each specific anticoagulation regimen (enoxaparin, unfractionated heparin, or bivalirudin) on the primary endpoint.
A total of 2,989 patients at low-to-intermediate risk were randomly assigned to PPA (n=1,494) or placebo (n=1,495). There were 37 patients (2.5%) experiencing the primary efficacy endpoint in both the PPA and placebo groups (HR 1.00; 95% confidence interval [CI], 0.63 to 1.57). Nonetheless, a significant interaction was observed for the anticoagulant type and the primary endpoint (p=0.015); the hazard ratios for each anticoagulant subcategory were as follows for enoxaparin (HR 0.46, 95% CI 0.22 to 0.98), unfractionated heparin (HR 3.71 95% CI 1.03 to 13.28) and bivalirudin (HR 1.24, 95% CI 0.60 to 2.59).
Contrary to data suggesting potential benefits of PPA, the RIGHT trial revealed that in a low-to-intermediate risk population, PPA did not confer a statistically significant reduction in the primary efficacy endpoint, which encompassed all-cause death, non-fatal myocardial infarction, non-fatal stroke, definite stent thrombosis, or urgent revascularization of any vessel within 30 days. Interestingly, an important interaction was observed based on the type of anticoagulant used. While enoxaparin showed potential benefit by reducing the risk of the primary endpoint, unfractionated heparin and bivalirudin did not demonstrate such advantages.
The trial’s principal investigator, Professor Shaoping Nie, emphasized that while the results suggest that anticoagulation after primary PCI for STEMI is safe, it did not show a substantial reduction in ischemic events in the specific low-to-intermediate risk population studied.
The RIGHT trial adds a significant layer of insight to the complex landscape of anticoagulation in the context of primary PCI for STEMI. By delving into the impact of PPA on a specific risk profile of patients, the trial helps guide clinical decision-making for this population. The trial’s recognition of the type-specific effects of anticoagulants underscores the importance of tailored approaches in cardiology. These findings encourage the pursuit of further research to elucidate the potential benefits of other anticoagulants in improving outcomes after primary PCI for STEMI.