What is the most appropriate next step for an old male patient with Diabetes Mellitus (DM) and Hypertension (HTN) presenting with chest pain and diaphoresis, with an electrocardiogram (ECG) showing ST-Elevation Myocardial Infarction (STEMI) in leads V2-3-4?

Immediate Coronary Angiography with Primary PCI

The most appropriate next step is A. Coronary angiogram, performed emergently as primary percutaneous coronary intervention (PCI) with a target door-to-balloon time of ≤120 minutes from first medical contact. 1

Rationale for Emergency Coronary Angiography

This patient presents with classic STEMI (chest pain, diaphoresis, ST-elevation in V2-V4), which represents complete coronary artery occlusion requiring immediate reperfusion therapy. 1, 2

Primary PCI is the gold standard reperfusion strategy for STEMI and reduces mortality from 9% to 7% when performed within 120 minutes of first medical contact. 2 The ESC guidelines explicitly state that reperfusion therapy is indicated in all patients with symptoms of ischemia <12 hours duration and persistent ST-segment elevation. 1

Why Not the Other Options?

• Coronary CT angiography (Option B) is explicitly contraindicated in STEMI. 1 The 2017 ESC guidelines give this a Class III recommendation (not recommended) because it delays definitive treatment and provides no therapeutic benefit in acute coronary occlusion. 1

• Myocardial perfusion scan (Option C) has no role in acute STEMI management. 1 While perfusion scintigraphy can be used in the triage of patients with uncertain chest pain to exclude major MI, 1 this patient has a clear STEMI diagnosis on ECG. Performing a perfusion scan would dangerously delay life-saving reperfusion therapy.

High-Risk Features in This Patient

This patient has multiple factors that make urgent intervention even more critical:

• Diabetes mellitus is independently associated with worse outcomes in STEMI, including impaired myocardial perfusion, increased distal embolization, and 3-fold higher mortality (12.6% vs 3.9%). 3, 4

• Anterior STEMI (V2-V4 involvement) carries higher mortality due to larger myocardial territory at risk. 1

• Hypertension and diabetes together increase procedural complexity and risk of complications. 4

Immediate Management Algorithm

1. Activate catheterization laboratory immediately - patient should bypass emergency department and go directly to cath lab if already in a PCI-capable center. 1

2. Administer dual antiplatelet therapy: 1

   • Aspirin loading dose
   • Potent P2Y12 inhibitor (prasugrel or ticagrelor preferred over clopidogrel, especially in diabetic patients who show greater benefit from more potent agents) 1

3. Anticoagulation: Parenteral anticoagulation (enoxaparin or unfractionated heparin) 1

4. Perform primary PCI with goal of restoring TIMI 3 flow 1

5. Monitor for reperfusion arrhythmias (bradycardia, accelerated idioventricular rhythm, ventricular tachycardia) which commonly occur with successful reperfusion 5

Critical Time Targets

• ECG interpretation: ≤10 minutes from first medical contact 1
• Primary PCI: ≤120 minutes from first medical contact 1, 2
• If PCI cannot be achieved within 120 minutes: Consider fibrinolytic therapy (tenecteplase, alteplase, or reteplase) followed by transfer for angiography within 24 hours 1, 2

Special Considerations for Diabetic Patients

• Monitor glucose closely - maintain blood glucose <11.0 mmol/L (200 mg/dL) while avoiding hypoglycemia 1
• Check renal function if patient is on metformin or SGLT2 inhibitors, as these require careful monitoring for at least 3 days post-PCI 1
• Expect higher rates of no-reflow phenomenon and consider adjunctive therapies (glycoprotein IIb-IIIa inhibitors, thrombectomy) 3

Common Pitfalls to Avoid

• Do not wait for cardiac biomarkers - reperfusion therapy should be initiated based on ECG findings alone 1
• Do not perform diagnostic imaging studies that delay angiography in clear STEMI 1
• Do not underestimate risk in diabetic patients - they require aggressive management despite often having atypical presentations 6, 4