STEMI reperfusion — structured viva

Stem

Practice viva. You run the cardiology service for a regional STEMI network. The examiner asks you to defend the network protocol, one decision at a time.

Branch A — Why 120 minutes?

Examiner: Where does the 120-minute limit come from, and what do the trials show?

Strong answer: ESC 2023 prefers a primary PCI strategy if it can be performed within 120 min of the ECG-based diagnosis.^[1] Contemporary data on the delay at which PCI loses its advantage are lacking. ESC 2023 therefore chose an absolute 120 min from diagnosis to wire crossing, equal to a relative PCI-related delay of 110–120 min.^[1] ACC/AHA 2025 sets FMC-to-first-device at 90 minutes or less, or 120 minutes or less for transfers.^[2] In DANAMI-2 (1572 patients with acute MI), transfer for angioplasty beat on-site alteplase at referral hospitals (8.5% vs 14.2% for death, reinfarction or disabling stroke at 30 days). Ninety-six percent of transfers took two hours or less.^[3] In PRAGUE-2 (patients with acute STEMI presenting within 12 h to the nearest community hospital without a catheter laboratory), patients randomised more than 3 h after onset had 15.3% mortality with thrombolysis vs 6% with transfer for PCI.^[4]

Follow-up: And when you cannot meet it? Answer: ESC 2023: fibrinolysis within 12 h of onset in patients without contraindications, started within 10 min of diagnosis, then immediate transfer.^[1] STREAM showed prehospital tenecteplase then angiography gave a similar outcome to primary PCI in patients with STEMI within 3 h of symptom onset who could not have primary PCI within 1 hour (12.4% vs 14.3%; RR 0.86, P=0.21).^[5][1] STREAM-2 enrolled patients aged 60 or older with 2 mm or more ST elevation in 2 contiguous leads who could not have primary PCI within 1 hour. Half-dose tenecteplase then angiography gave a 30-day composite similar to primary PCI (12.8% vs 13.3%; RR 0.96), but intracranial haemorrhage occurred in 1.5% (none with primary PCI).^[6]

Branch B — The ECG

Examiner: A patient has pain and LBBB. Do you activate the lab?

Strong answer: ESC 2023 says that, with a high clinical suspicion of ongoing ischaemia, LBBB, RBBB or a paced rhythm prevents accurate assessment of ST elevation. With signs or symptoms highly suspicious for ongoing ischaemia, they are managed like clear ST elevation, whether or not the block was known before.^[1] ACC/AHA 2025 differs: new LBBB is not diagnostic of AMI in isolation, and in an asymptomatic patient it is not a STEMI equivalent.^[2] Smith 2012 compared admission ECGs of patients with an acutely occluded coronary artery and LBBB with ECGs of emergency department controls with chest pain or dyspnoea and LBBB but without coronary occlusion. The modified Sgarbossa rule replaced the 5 mm discordant criterion with an ST/S ratio of −0.25 or less. Sensitivity rose to 91% with specificity of 90%, in a small study.^[28]

Follow-up: Which other ECG findings suggest occlusion? Answer: The ESC 2023 text gives as examples V1–V3 ST depression or V7–V9 elevation for posterior occlusion, and V3R/V4R elevation for RV ischaemia. It also lists ST depression of 1 mm or more in six or more leads with elevation in aVR and/or V1 for left main or multivessel ischaemia.^[1]

Branch C — Drugs in the lab

Examiner: Which P2Y12 inhibitor and anticoagulant do you use for primary PCI?

Strong answer: ESC 2023 recommends aspirin plus prasugrel or ticagrelor by default: aspirin for all patients without contraindications (Class I, Level A); prasugrel in P2Y12-naïve patients proceeding to PCI (Class I, Level B); ticagrelor (Class I, Level B). Prasugrel should be considered in preference to ticagrelor for ACS patients who proceed to PCI (Class IIa, Level B).^[1] In ISAR-REACT 5 (ACS patients for whom invasive evaluation was planned), death, MI or stroke at 1 year was 9.3% with ticagrelor vs 6.9% with prasugrel.^[26] Prasugrel is a 60 mg load then 10 mg daily (5 mg if under 60 kg; at 75 or older use with caution, 5 mg daily if deemed necessary), and prior stroke is a contraindication.^[1] UFH is the default anticoagulant. In STEMI undergoing primary PCI, enoxaparin and bivalirudin with a full-dose post-PCI infusion should be considered as alternatives (Class IIa, Level A each), and fondaparinux is not recommended (Class III, Level B).^[1] If bivalirudin is used, give the full-dose infusion after PCI: 4 h in ESC 2023 and 2–4 hours in ACC/AHA 2025.^[1][2]

Follow-up: Aspiration and access? Answer: ESC 2023 recommends radial access as the standard approach, unless there are overriding procedural considerations (Class I, Level A). In MATRIX (8404 patients with ACS, with or without STEMI, about to undergo coronary angiography and PCI; 47.6% STEMI), net adverse clinical events were 9.8% with radial vs 11.7% with femoral access (RR 0.83).^[1][13] Routine thrombus aspiration is not recommended (Class III, Level A).^[1] In patients with STEMI undergoing primary PCI, TOTAL found no reduction in its 180-day primary outcome (6.9% vs 7.0%), and stroke within 30 days was higher with thrombectomy (0.7% vs 0.3%).^[12]

Branch D — After the culprit

Examiner: The culprit is stented. There is a severe stenosis in another vessel and the patient is stable.

Strong answer: In haemodynamically stable STEMI undergoing primary PCI, ESC 2023 recommends complete revascularisation during the index PCI or within 45 days (Class I, Level A), with non-IRA PCI based on angiographic severity (Class I, Level B).^[1] In COMPLETE (STEMI with multivessel disease after successful culprit-lesion PCI), cardiovascular death or MI at a median of 3 years was 7.8% with complete revascularisation vs 10.5% with culprit-lesion-only PCI (HR 0.74).^[14] In MULTISTARS AMI (haemodynamically stable patients with STEMI and multivessel disease), immediate multivessel PCI was noninferior to staged PCI for the 1-year composite of death, nonfatal MI, stroke, unplanned ischaemia-driven revascularisation or HF hospitalisation (8.5% vs 16.3%).^[15] ACC/AHA 2025 accepts single or staged procedures, with some preference for a single procedure.^[2]

Follow-up: And if he were in shock? Answer: ESC 2023: IRA-only PCI during the index procedure is recommended (Class I, Level B); ACC/AHA 2025 likewise recommends culprit-vessel-only PCI in cardiogenic shock.^[1][2] In CULPRIT-SHOCK (multivessel disease, acute MI and cardiogenic shock), 30-day death or renal replacement therapy was 45.9% with culprit-only PCI vs 55.4% with immediate multivessel PCI.^[18]

Branch E — Shock support

Examiner: Would you put in a balloon pump or a pump?

Strong answer: Routine IABP is not recommended in cardiogenic shock without mechanical complications (ESC 2023 Class III, Level B). IABP-SHOCK II (cardiogenic shock complicating acute MI, all expected to undergo early revascularisation) found no significant difference in 30-day mortality: 39.7% vs 41.3% (P=0.69).^[1][20] ECLS-SHOCK (acute MI with cardiogenic shock and planned early revascularisation) found no reduction in 30-day death (47.8% vs 49.0%) and more bleeding.^[21] In DanGer Shock (STEMI with cardiogenic shock), a microaxial flow pump reduced 180-day death (45.8% vs 58.5%) but increased the composite safety end point (24.0% vs 6.2%).^[22] ACC/AHA 2025 finds the pump reasonable in patients matching the trial criteria. The trial enrolled STEMI with cardiogenic shock of under 24 hours: SBP under 100 mm Hg or vasopressor support, end-organ hypoperfusion (lactate 2.5 mmol/L or more and/or SvO2 under 55% with a normal PaO2), and LVEF under 45%. Patients comatose (GCS under 8) after out-of-hospital cardiac arrest and those with overt RV failure were excluded.^[2]

Branch F — The late and the long term

Examiner: A stable, pain-free patient arrives on day 4 with an occluded artery. Then: when do you discuss an ICD?

Strong answer: ESC 2023 says routine PCI of an occluded IRA more than 48 h after symptom onset without persistent symptoms is not recommended (Class III, Level A).^[1] In OAT (stable patients with total occlusion of the IRA 3 to 28 days after MI and a high-risk criterion: EF under 50% or proximal occlusion), PCI did not reduce death, reinfarction or class IV HF at 4 years (17.2% vs 15.6%).^[10] A primary-prevention ICD within 40 days of MI is generally not indicated; an ICD or wearable defibrillator may be considered in selected patients: incomplete revascularisation, pre-existing LV dysfunction, arrhythmias more than 48 h after STEMI onset, or polymorphic VT or VF (Class IIb, Level C). If pre-discharge LVEF is 40% or less, repeat LVEF evaluation 6–12 weeks after the ACS (after complete revascularisation and optimal therapy) is recommended (Class I, Level C).^[1] DINAMIT enrolled patients 6 to 40 days after MI with LVEF 0.35 or less and impaired cardiac autonomic function. IRIS enrolled patients 5 to 31 days after MI with either LVEF 40% or less and a heart rate of 90/min or more, or non-sustained VT (150/min or more), or both. Neither found an overall mortality benefit from early ICD (HR 1.08, P=0.66; HR 1.04, P=0.78).^[33][34]