NSTE-ACS — structured written assessment

SAQ 1 (10 marks)

Practice scenario. A 67-year-old man has had three episodes of rest chest pain over 3 hours, each lasting about 20 minutes. He is now pain-free and has had no treatment before arrival. BP 142/86 mmHg, HR 78/min, chest clear. His first ECG shows no ST elevation; a repeat ECG 30 minutes later shows new T-wave inversion in V2–V4 that was absent on the first.^[1] His hs-troponin meets the rule-in criteria of the ESC 0 h/1 h algorithm for the laboratory assay, with a rise and fall above the sex-specific 99th percentile upper reference limit on serial testing.^[1][29]

1. State his working diagnosis and his final diagnosis under the 2023 ESC ACS guideline, and why. (2)^[1]
2. Classify his risk and give the timing of angiography under ESC 2023, then state the ACC/AHA 2025 position. (4)^[1][2]
3. List the variables of the in-hospital GRACE risk score as tabulated in the 2025 ACC/AHA guideline. (2)^[2]
4. Name two randomised trials of early versus delayed angiography in NSTE-ACS and give their main results. (2)^[7][8]

Model answers

1. Working diagnosis: NSTE-ACS, because he has chest pain without persistent ST elevation or equivalents.^[1] Final diagnosis: NSTEMI. ESC 2023 says a rise and/or fall in troponin above the 99th percentile with ischaemic symptoms points to MI under the Fourth UDMI (2018), a framing now dated; most NSTE-ACS patients who show this typical rise and fall receive a final diagnosis of NSTEMI.^[1] In ESC 2023, patients whose troponin stays below the 99th centile receive a final diagnosis of UA.^[1] Under the current Fifth UDMI (2026), his spontaneous acute myocardial injury, with ischaemic symptoms and new T-wave inversion and no alternative acute trigger, makes primary MI likely; an acute coronary pathology at angiography would confirm it.^[29]
2. ESC 2023: he has no very high-risk feature: he is stable and now pain-free, without recurrent or refractory chest pain despite medical treatment (his episodes occurred before any treatment), acute heart failure, in-hospital life-threatening arrhythmia or mechanical complication, and one new T-wave change is not a recurrent dynamic change.^[1] He has two high-risk features, confirmed NSTEMI by the ESC hs-cTn algorithm and dynamic T-wave changes, so early angiography within 24 h should be considered (Class IIa, Level A) and an inpatient invasive strategy is recommended (Class I, Level A).^[1] ACC/AHA 2025: at intermediate or high ischaemic risk, an invasive approach with intent to revascularise is recommended during hospitalisation. The benefit of early versus delayed timing is unclear.^[2]
3. Age, Killip class, systolic blood pressure, heart rate, ST-segment deviation, cardiac arrest on admission, serum creatinine and elevated cardiac biomarkers.^[2] ESC 2023 says established risk scores such as GRACE should be considered for prognosis estimation (Class IIa, Level B); its text notes GRACE has the best discriminative performance.^[1]
4. TIMACS: 3031 patients, angiography within 24 h vs at 36 h or later. The composite of death, MI or stroke at 6 months was 9.6% with early vs 11.3% with delayed angiography (HR 0.85, P=0.15); early intervention improved the primary outcome in the highest-risk third (HR 0.65).^[7] VERDICT: 2147 patients, angiography within 12 hours vs 48 to 72 hours. Over a median 4.3 years, the primary composite (all-cause death, recurrent MI, admission for refractory ischaemia or for heart failure) was 27.5% with very early vs 29.5% with standard-timing angiography (HR 0.92); with GRACE over 140 the HR was 0.81.^[8]

SAQ 2 (10 marks)

Practice scenario. The man in SAQ 1 weighs 80 kg and has no history of stroke, TIA or bleeding. Creatinine clearance is 85 mL/min. Angiography is booked for 20 hours after his diagnosis.^[1]

1. Give the antiplatelet plan before angiography under ESC 2023, with one supporting trial. (3)^[1][13]
2. Choose his parenteral anticoagulant before angiography and give the ESC 2023 dose. (2)^[1]
3. He has PCI to a proximal LAD lesion. Choose the P2Y12 inhibitor and dose, and the default DAPT duration, citing the trial behind the ESC preference. (3)^[1][12]
4. At 4 months he is event-free and asks to stop one of his antiplatelet drugs. Outline the ESC 2023 and ACC/AHA 2025 options. (2)^[1][2]

Model answers

1. Aspirin loading dose now: 150–300 mg orally, or 75–250 mg IV if oral ingestion is not possible, then 75–100 mg once daily (ESC 2023 Table 6), started as soon as possible; aspirin is recommended for all patients without contraindications (Class I, Level A).^[1] No routine P2Y12 pretreatment, because early (under 24 h) angiography is planned and the anatomy is unknown (Class III, Level A); give the loading dose at the time of PCI.^[1] ACCOAST: compared with placebo, a prasugrel 30 mg pretreatment loading dose did not significantly change the primary composite through day 7 (cardiovascular death, MI, stroke, urgent revascularisation or GP IIb/IIIa bailout; HR 1.02) and increased TIMI major bleeding through day 7 (HR 1.90).^[13]
2. UFH is recommended for patients going to immediate or early angiography: IV bolus 70–100 U/kg, then an infusion titrated to an aPTT of 60–80 s.^[1] Enoxaparin 1 mg/kg SC twice daily (1 mg/kg once daily if CrCl is below 30 mL/min) should be considered as an alternative (Class IIa, Level B).^[1]
3. Prasugrel 60 mg orally as loading, then 10 mg once daily (he is 80 kg, under 75 and has no prior stroke).^[1] ESC 2023 says prasugrel should be considered in preference to ticagrelor for patients proceeding to PCI (Class IIa, Level B).^[1] In ISAR-REACT 5, the primary composite of death, MI or stroke at 1 year was 6.9% with prasugrel vs 9.3% with ticagrelor (HR 1.36 for ticagrelor), with no significant difference in BARC major bleeding (4.8% vs 5.4%).^[12] Default DAPT is generally recommended for 12 months after PCI, unless there are contraindications; a P2Y12 inhibitor in addition to aspirin for 12 months unless there is HBR is Class I, Level A.^[1]
4. ESC 2023: single antiplatelet therapy (preferably a P2Y12 inhibitor) should be considered if event-free after 3–6 months of DAPT and not at high ischaemic risk (Class IIa, Level A).^[1] ACC/AHA 2025: ticagrelor monotherapy is recommended 1 month or more after PCI in patients who tolerated ticagrelor DAPT, but the safety of prasugrel monotherapy at 1 month or more after ACS has not been established.^[2]