AIMS
Patients with atrial fibrillation presenting with STEMI or NSTEMI and undergoing PCI face competing risks of thrombosis and bleeding. While dual antithrombotic therapy reduces bleeding, selected high-risk patients may benefit from short-term triple therapy. This study seeks to identify high-bleeding risk AF patients undergoing PCI for AMI who are likely to benefit from triple therapy - as defined by the REDUAL-PCI score - thereby aiding clinicians in balancing bleeding and ischemic risks more precisely.

METHODS AND RESULTS
We conducted a retrospective analysis of 147 consecutive patients with documented atrial fibrillation who were admitted with STEMI or NSTEMI and underwent PCI. Eligible patients were those receiving oral anticoagulants for stroke prevention in AF and undergoing successful PCI with stent implantation. Bleeding risk was assessed using established criteria such as HAS-BLED, PRECISE-DAPT, PRECISE-HBR scores, ARC-HBR consensus, ans ARC-HBR trade-off model to quantify baseline bleeding susceptibility. Clinical and procedural variables required for REDUAL-PCI risk score calculation included left ventricular ejection fraction, extent of coronary disease, MI indication, peripheral artery disease, platelet count, and estimated glomerular filtration rate. The REDUAL-PCI risk score was applied to categorize patients into thrombotic risk strata. A predefined score threshold (e.g., ≥5 points) was used to identify patients at high ischemic risk who may derive a net clinical benefit from triple antithrombotic therapy.
The median REDUAL-PCI score was 5 (IQR 3-5) points. Based on the REDUAL-PCI score ≥5 points we identified 104 (70,7%) patients at high ischemic risk who may derive a net clinical benefit from triple antithrombotic therapy despity beeing at high bleeding risk (HBR).
Patients with a REDUAL‑PCI score ≥5, indicating higher ischemic risk and potential benefit from prolonged triple antithrombotic therapy, were similar in age (73±11 vs 74±8 years; p=0.52) and sex distribution (64.4% vs 72.1% male; p=0.36) compared with patients with a score <5. REDUAL ≥5 patients had lower rates of STEMI presentation (31.7% vs 58.1%; p=0.003) but higher prevalence of prior MI (43.3% vs 18.6%; p=0.004), chronic kidney disease (48.1% vs 16.3%; p=0.0003), and complex PCI (45.2% vs 16.3%; p=0.0009). They also exhibited higher ARC-HBR major (1.5±0.7 vs 1.3±0.5; p=0.04) and minor criteria (1.4±0.8 vs 1.0±1.0; p=0.05), with elevated estimated BARC 3–5 bleeding risk (12.5%±9.2% vs 9.6%±5.9%; p=0.05) and markedly higher estimated MI/stent thrombosis risk (8.5%±4.9% vs 5.7%±3.0%; p=0.0005). PRECISE-DAPT and PRECISE-HBR scores were also higher in REDUAL ≥5 patients (PRECISE-DAPT 31±11 vs 26±10, p=0.01; PRECISE-HBR 33±6 vs 30±6, p=0.02), with a greater proportion classified in the major/very-high bleeding risk strata. ARC-HBR bleeding-thrombosis risk trade-off analysis revealed a significant shift toward ischemic-dominant profiles in REDUAL ≥5 patients (35.6% vs 11.6% in REDUAL <5; p=0.01), confirming that despite high bleeding risk, a substantial subset has ischemic risk exceeding bleeding risk.

CONCLUSIONS
The integration of REDUAL-PCI and ARC-HBR trade-off demonstrates that even among high bleeding risk patients, a subset has ischemic-dominant profiles and may benefit from prolonged triple antithrombotic therapy.