In a recent randomized, three-arm, parallel, blinded study by Dr. Schnorbus, published in European Heart Journal, prasugrel was associated with improved endothelial function, more potent platelet inhibition, and decreased plasma interleukin (IL)-6 levels in patients undergoing stent placement for acute coronary syndrome (ACS) compared to ticagrelor and clopidogrel. These effects were observed in patients who received prasugrel 2 hours before stenting.
Coronary artery stenting has been associated with impaired coronary and peripheral endothelial function as well as an inflammatory response leading to the release of mediators and subsequent platelet aggregation. These phenomena are associated with in-stent restenosis as well as adverse prognostic outcomes after percutaneous coronary intervention (PCI). Platelet inhibitors, such as P2Y12 receptor inhibitors, are administered prior and after coronary interventions to address these adverse effects. However, previous studies have suggested that differences exist among P2Y12 inhibitors in terms of their efficacy.
In a prospective, single-center study, a total of 90 patients with unstable angina or non-ST elevation myocardial infarction (NSTEMI) undergoing coronary stenting were randomized to receive a single dose of clopidogrel (600mg), prasugrel (60mg), or ticagrelor (180mg) followed by chronic therapy with the same drug. Patients with elevated c reactive protein (CRP), infective or inflammatory disorders, personal history of prior coronary interventions, impaired hepatic/renal function, those with heart failure, and those with ST elevation myocardial infarction (STEMI) were excluded from the study. The primary endpoint of the study was the change in flow-mediated dilation (FMD) of the conduit artery over a period of 1 day, 1 week, and 1 month after PCI. Secondary endpoints were the effect of study medications on macrovascular and microvascular function, platelet aggregation, and inflammatory stress.
The study showed that antiplatelet therapy immediately before stenting was associated with improved FMD without a significant difference among study medications. On the first follow-up after PCI and later follow-up visits, prasugrel was associated with a stronger platelet reactivity inhibition and improved endothelial function. These effects were limited to those who received prasugrel before catheterization. Prasugrel platelet inhibitory effect was more obvious in NSETMI patients than in those with unstable angina. Prasugrel therapy also led to a more pronounced decrease in IL-6 levels. According to the author, “when administered pre-PCI, prasugrel, but not the other agents, limits stent-induced endothelial dysfunction and inflammation in ACS.” This study is limited by its small size and future studies are needed to further confirm these conclusions.