Prehospital Tirofiban Increases the Rate of Disrupted Myocardial Infarction in Patients with ST-Segment Elevation Myocardial Infarction: Insights From the On-TIME 2 Trial (2024)

Background

In patients with ST-segment elevation myocardial infarction (STEMI), prehospital tirofiban significantly improved myocardial reperfusion. However, its impact on the rate of disrupted myocardial infarction (MI), particularly in the context of high-sensitive cardiac troponin (hs-cTn) assays, is still unclear.

Methods

The On-TIME 2 (The Ongoing Tirofiban In Myocardial infarction Evaluation 2) trial randomly assigned STEMI patients to prehospital tirofiban or placebo before transportation to a percutaneous coronary intervention (PCI) centre. In this post hoc analysis, we evaluated STEMI patients that underwent primary PCI and had measured hs-cTn levels. Troponin T levels were collected at 18-24 h and 72-96 h after PCI. Disrupted MI was defined as peak hs-cTn T levels ≤10 times the upper limit of normal (≤140 ng/L).

Results

Out of 786 STEMI patients, 47 (6%) had a disrupted MI. Disrupted MI occurred in 31 of 386 patients (8.0%) in the tirofiban arm and in 16 of 400 patients (4.0%) in the placebo arm (p=0.026). After multivariate adjustment, prehospital tirofiban remained independently associated with disrupted MI (OR 2.03; 95% CI 1.10 to 3.87; P= 0.027). None of the patients with disrupted MI died during the one-year follow-up, compared to a mortality rate of 2.6% among those without disrupted MI.

Conclusion

Among STEMI patients undergoing primary PCI, the use of prehospital tirofiban was independently associated with a higher rate of disrupted MI. These results, highlighting a potential benefit, underscore the need for future research focusing on innovative pretreatment approaches which may increase the rate of disrupted MI.