The incidence of cardiovascular events in the first year following a primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI) is comparable between patients given prasugrel and ticagrelor post-surgery, according to results of the PRAGUE-18* trial presented at AHA 2017.

“Prasugrel and ticagrelor are similarly effective and safe during the first year after MI,” said study investigator Dr Zuzana Motovska from the Charles University and University Hospital Kralovske Vinohrady, Prague, Czech Republic.

“One-year outcomes … did not confirm the hypothesis that one of the potent P2Y₁₂ inhibitors was more efficient and/or safer than the other,” said Motovska and her colleagues.

Participants were 1,230 patients (mean age 61.8 years) with AMI who had undergone primary PCI and were randomized to receive prasugrel (n=634) or ticagrelor (n=596) for an intended 12 months.

As cost of the drugs was borne by the patients without reimbursement, they were allowed to switch to clopidogrel for economic purposes, which was done by 34.1 (n=216) and 44.4 percent (n=265) of patients on prasugrel and ticagrelor, respectively, over the 12-month follow-up period, with a median of 8 days on the study drug prior to switch.

The incidence of a composite of cardiovascular death, nonfatal MI, and stroke was comparable between patients on prasugrel and ticagrelor (6.6 percent vs 5.7 percent, hazard ratio [HR], 1.167, 95 percent confidence interval [CI], 0.742–1.835; p=0.503). [AHA 2017, abstract LBS.05; J Am Coll Cardiol 2017;doi:10.1016/j.jacc.2017.11.008]

Patients on prasugrel and ticagrelor also fared similarly in terms of cardiovascular death (3.3 percent vs 3.0 percent; p=0.769), nonfatal MI (3.0 percent vs 2.5 percent; p=0.611), stroke (1.1 percent vs 0.7 percent; p=0.423), all-cause mortality (4.7 percent vs 4.2 percent; p=0.654), definite stent thrombosis (1.1 percent vs 1.5 percent; p=0.535), all bleeding (10.9 percent vs 11.1 percent; p=0.999), and thrombolysis in MI (TIMI) major bleeding (0.9 percent vs 0.7 percent; p=0.754).

Patients who switched to clopidogrel for economic reasons had a reduced risk of cardiovascular death, nonfatal MI, and stroke (HR, 0.281, 95 percent CI, 0.152–0.520; p<0.001) and bleeding (HR, 0.514, 95 percent CI, 0.350–0.755; p=0.001) compared with those who continued study drugs.

“Economically motivated, early post-discharge switch to clopidogrel, when approved by treating physicians, was not associated with increased risk of ischaemic events,” said Motovska.

According to study discussant Professor Roxana Mehran from the Icahn School of Medicine at Mount Sinai, New York, US, this trial represents a real-world scenario where patients have to cover the costs of their post-discharge medications in accordance with local regulations. This explains the switch to clopidogrel, the cost of which is covered by local healthcare, she said.

The study shows that switching to clopidogrel is a common occurrence, and that “economically driven, physician directed de-escalation seems feasible”, said Mehran, though she cautioned that the study was underpowered to assess the efficacy and safety of switching treatments.

“These observations … require large randomized trials to evaluate the safety and efficacy of switching [de-escalation],” she said.