Tailoring dual antiplatelet therapy (DAPT) for patients who have undergone percutaneous coronary intervention (PCI) based on a risk score—taking into account the patient’s ischaemic and bleeding risk—lowers their risk of net adverse clinical events (NACE) compared to a standard 12-month DAPT regime.
This is the headline finding of the PARTHENOPE trial, a randomised trial comparing outcomes in patients who received a “personalised” course of DAPT lasting either three, six or 24 months based upon their risk score criteria, against those undergoing the standard 12 months of DAPT in line with guideline recommendations.
Presenting findings of the study at the 2025 European Society of Cardiology (ESC) congress (29 August–1 September, Madrid, Spain), Raffaele Piccolo (University of Naples Federico II, Naples, Italy) reported that the benefit of the personalised DAPT regime was principally related to a lower risk of ischaemic events, including myocardial infarction (MI) and urgent target-vessel revascularisation, and the strategy was not associated with any excess of bleeding compared to a standard approach.
Current guidelines recommend DAPT for 12 or six months followed by aspirin monotherapy after PCI in chronic coronary syndrome patients and for 12 months after PCI in patients with acute coronary syndrome, said Piccolo during his presentation of the trial’s results at ESC 2025, though the optimal duration of DAPT remains highly debated.
“In the past few years several risk scores have been proposed to guide the duration of DAPT, however, there has been no prospective validation of these scores, and in this context the DAPT score is probably a unique tool that enables evaluation at the same time the ischaemic and bleeding risk profile,” he explained.
PARTHENOPE investigators used the DAPT Score developed by Robert Yeh (Beth Israel Deaconess Medical Center, Boston, USA) which uses nine clinical variables including age, smoking status, diabetes, prior MI or PCI and others to stratify patients’ risk from low to high to inform their strategy for DAPT.
“We are used to seeing score validation based on calibration and discrimination metrics, which is great,” Piccolo comments to Cardiovascular News. “However, a true test of a score’s utility is whether randomisation to a score-guided versus unguided strategy is clinically useful. This is probably one of the principal novelties of PARTHENOPE.”
Patients randomised to the standard DAPT arm received DAPT for 12 months with P2Y12 inhibitors and aspirin, followed by aspirin monotherapy for a further 12 months.
For those randomised to the personalised therapy arm, if they had a low DAPT score, those with chronic coronary syndrome received P2Y12 inhibitors plus aspirin for three months, followed by aspirin monotherapy up to 24 months, or P2Y12 inhibitors plus aspirin for six months followed by aspirin monotherapy up to 24 months for those with acute coronary syndromes. Patients with high DAPT scores received or P2Y12 inhibitors plus aspirin for the full 24 months.
The primary NACE endpoint of the trial was a composite of all-cause death, MI, stroke, urgent target vessel revascularisation and BARC type II, III or V bleeding.
Among the 2,107 patients enrolled in the trial, Piccolo reported that there was a high prevalence of diabetes, whilst acute coronary syndrome made up more than 70% of the cases. Patients had a median DAPT score of 2, whilst 60% were considered to have a high score.
Among the patients randomised to personalised DAPT, 15.2% of patients had three months, 24.5% six months, and 60.3% had 24 months.
The primary endpoint occurred in 22.2% of patients in the standard DAPT group, Piccolo detailed, compared to 18.6% in the personalised DAPT group, with a statistically significant p-value of 0.04 which corresponded to a relative reduction of 20% for the risk of NACE.
“If we look at the components of the primary endpoint, I think it is important to highlight that most of the benefit was driven by a decreased risk of any myocardial infarction and urgent target vessel revascularisation,” Piccolo explained. “There was no excess of bleeding in the patients randomised to the personalised versus standard DAPT strategy.”
Landmark analysis of the data revealed that most of the benefit was seen late—from 12 to 24 months—and was attributable to a reduction in ischaemic rather than the bleeding component of the endpoint.
“In an almost all-comer PCI population, a personalised DAPT duration, gradually extended from three to 24 months based on the DAPT score, was superior to a standard 12-month approach in terms of net clinical benefit,” Piccolo said in his concluding remarks. “The benefit from personalised DAPT emerged during late follow-up—from 12 to 24 months—and the reduction in NACE was principally related to a lower risk of ischaemic events, including myocardial infarction and urgent target-vessel revascularisation.
“A personalised DAPT strategy was not associated with an excess of bleeding in comparison to a standard DAPT strategy.”
Commenting to Cardiovascular News, Piccolo added: “If one focuses on patients at high ischaemic risk—a high DAPT score—there is no additional risk of extending DAPT in terms of bleeding. So far, we have a large number of studies that helped in identifying patients who will bleed. At variance, this one helps in identifying patients who will not bleed on DAPT.”
The study’s results were simultaneously published in the Journal of the American College of Cardiology. The study’s principal investigator was Giovanni Esposito (University of Naples Federico II, Naples, Italy).
