What is the full treatment for a 50-year-old male with myocardial infarction (heart attack)?

Comprehensive Treatment of Myocardial Infarction in a 50-Year-Old Male

For a 50-year-old male with myocardial infarction, immediate reperfusion therapy via primary PCI (if available within 120 minutes) or fibrinolytic therapy (if PCI cannot be performed timely) combined with aspirin, anticoagulation, and beta-blockers forms the cornerstone of treatment to reduce mortality and morbidity. 1

Immediate Emergency Department Management (First 10-20 Minutes)

Upon arrival, the patient should receive the following immediately:

• Oxygen by nasal prongs (only if SaO₂ < 90%; avoid routine oxygen in non-hypoxemic patients as hyperoxia may increase myocardial injury) 1, 2
• Aspirin 160-325 mg orally (chewed and swallowed for faster absorption), unless systolic BP < 90 mmHg or contraindicated 1
• Sublingual nitroglycerin (unless systolic BP < 90 mmHg, heart rate < 50 or > 100 bpm) 1
• Morphine sulfate or meperidine for adequate analgesia to relieve pain and anxiety 1, 2
• 12-lead ECG within 10 minutes to determine reperfusion strategy 1

Critical Decision Point: ST-segment elevation ≥1 mm in contiguous leads or new left bundle branch block indicates need for immediate reperfusion therapy 1

Reperfusion Strategy (Time-Critical)

Primary PCI (Preferred Method)

Primary PCI is the preferred reperfusion strategy when it can be performed within 120 minutes of STEMI diagnosis by experienced operators. 1

• Transfer patient directly to catheterization laboratory, bypassing emergency department if coming from another facility 1
• Administer high-dose intravenous heparin during procedure 1
• Give potent P2Y12 inhibitor (prasugrel or ticagrelor preferred over clopidogrel) before or during PCI, maintained for 12 months 1

Fibrinolytic Therapy (If PCI Not Available Timely)

If primary PCI cannot be performed within 120 minutes, initiate fibrinolytic therapy immediately, preferably in pre-hospital setting. 1

• Use fibrin-specific agents (tenecteplase, alteplase, or reteplase) 1
• Greatest benefit occurs within first 6 hours (35 lives saved per 1000 patients treated in first hour vs. 16 lives saved per 1000 when given 7-12 hours after symptom onset) 1
• Add clopidogrel to aspirin 1
• Anticoagulation with enoxaparin IV followed by subcutaneous (preferred over unfractionated heparin) or weight-adjusted UFH bolus followed by infusion 1
• Transfer to PCI-capable center immediately after fibrinolysis for angiography between 2-24 hours 1
• Perform rescue PCI immediately if fibrinolysis fails (< 50% ST-segment resolution at 60-90 minutes) 1

Important Caveat: Thrombolytic therapy increases risk of intracranial hemorrhage, especially in patients > 65 years, body weight < 70 kg, or hypertension 1

First 24 Hours of Hospitalization

Continuous Monitoring

• Continuous electrocardiographic monitoring with defibrillator, atropine, lidocaine, transcutaneous pacing patches, and epinephrine immediately available 1
• Serial ECGs and cardiac troponin measurements to confirm diagnosis 1
• Limit physical activity for at least 12 hours 1

Pharmacological Management

Beta-Blockers (Critical for Mortality Reduction):

• Intravenous beta-blocker therapy (metoprolol 5 mg IV every 2 minutes for 3 doses, then 50 mg orally every 6 hours for 48 hours, followed by 100 mg twice daily) should be initiated early, provided no contraindications 1, 3
• Do NOT administer to patients with signs of heart failure, low-output state, or risk factors for cardiogenic shock 2
• Beta-blockers reduce morbidity and mortality regardless of whether reperfusion therapy was given 1

Nitroglycerin:

• Intravenous nitroglycerin for 24-48 hours (not oral preparations due to inability to titrate in acute setting) 1
• Avoid in patients with hypotension, bradycardia, excessive tachycardia, or right ventricular involvement (can cause profound hypotension) 1, 2

Anticoagulation:

• For patients receiving alteplase, continue IV heparin for 48 hours 1
• For large anterior MI or LV mural thrombus on echocardiography, administer IV heparin to reduce embolic stroke risk 1

Magnesium:

• Magnesium sulfate as needed to replete deficits for 24 hours 1

Avoid:

• Prophylactic antiarrhythmic agents (lidocaine increases risk of asystole and mortality) 1
• Calcium channel blockers (not shown to reduce mortality and may be harmful) 1
• NSAIDs except aspirin (increase mortality and complications) 2

After First 24 Hours Through Hospitalization

Continued Pharmacotherapy

• Aspirin 160-325 mg daily indefinitely 1
• Oral beta-blocker for at least 6 weeks (continue indefinitely if heart failure or LVEF < 40%) 1
• ACE inhibitor initiated within 24 hours in patients with heart failure, LVEF dysfunction, diabetes, or anterior infarction 1

Complication Management

Heart Failure:

• IV furosemide and afterload-reducing agent 1

Cardiogenic Shock:

• Consider intra-aortic balloon pump and emergency coronary angiography followed by PCI or CABG 1

Right Ventricular Infarction (Up to 50% of Inferior MIs):

• Obtain V4R lead early (ST elevation may resolve within 10 hours) 4
• Vigorous IV volume expansion with normal saline for hypotension 1, 2, 4
• Avoid nitrates and diuretics (reduce preload and cause profound hypotension) 2, 4
• Consider inotropic support with dobutamine if cardiac output remains low after volume loading 2

Recurrent Chest Pain:

• If pericarditis: high-dose aspirin 650 mg every 4-6 hours 1
• If myocardial ischemia: IV nitroglycerin, analgesics, antithrombotic medications (aspirin, heparin), and consider coronary angiography with revascularization 1

Bradycardia/Heart Block:

• Symptomatic sinus bradycardia: IV atropine 0.3-0.5 mg, repeated up to 1.5-2.0 mg total 1, 2
• Type II second-degree or complete AV block: temporary pacing 1

Pre-Discharge Evaluation (4-14 Days)

• Routine echocardiography to assess LV and RV function, detect mechanical complications, and exclude LV thrombus 1
• Exercise stress testing (submaximal at 4-7 days or symptom-limited at 10-14 days) to assess functional capacity, evaluate medical regimen efficacy, and stratify risk 1

Long-Term Management (Indefinite)

Pharmacotherapy

• Aspirin 75-100 mg daily indefinitely 1
• Dual antiplatelet therapy (aspirin plus ticagrelor or prasugrel, or clopidogrel if unavailable/contraindicated) for 12 months after PCI 1
• Beta-blocker indefinitely 1
• ACE inhibitor at selected dose indefinitely 1
• High-intensity statin therapy with goal LDL < 100 mg/dL 1
• PPI if high gastrointestinal bleeding risk with dual antiplatelet therapy 1

Lifestyle Modifications

• Smoking cessation with repeated counseling, nicotine replacement therapy, varenicline, and/or bupropion 1
• Cardiac rehabilitation program participation 1
• Diet low in saturated fat and cholesterol, achieve ideal weight 1
• Exercise at least 20 minutes at brisk walking level, minimum three times weekly 1

Critical Pitfalls to Avoid

• Never give nitrates to patients with right ventricular involvement (causes profound hypotension) 2, 4
• Never give beta-blockers to patients in low-output state or with signs of heart failure/cardiogenic shock 2
• Never delay reperfusion therapy (time is muscle; every 30-minute delay increases mortality) 1
• Never use calcium channel blockers acutely (not shown to reduce mortality and may be harmful) 1
• Never use prophylactic lidocaine (increases asystole risk and mortality) 1
• Never give routine oxygen to non-hypoxemic patients (hyperoxia may worsen myocardial injury) 2