Acute Medication Management for Suspected ACS with Stent Thrombosis
Immediately administer dual antiplatelet therapy with aspirin 150-300 mg loading dose plus ticagrelor 180 mg loading dose, initiate intravenous beta-blocker therapy to control heart rate and blood pressure, start parenteral anticoagulation with unfractionated heparin or enoxaparin, and give intravenous nitroglycerin for ongoing chest pain while preparing for emergent coronary angiography within 2 hours. 1, 2, 3
Immediate Antiplatelet Therapy
Administer aspirin 150-300 mg oral loading dose immediately (or 75-250 mg IV if unable to take oral), followed by 75-100 mg daily maintenance. 2, 3
Add ticagrelor 180 mg loading dose immediately, then 90 mg twice daily. Ticagrelor is strongly preferred over clopidogrel in this high-risk scenario with suspected stent thrombosis and ongoing ischemia. 2, 3
Do not use prasugrel in this acute setting if the patient has any history of prior stroke or TIA, age ≥75 years, or weight <60 kg, as it is contraindicated or carries excessive bleeding risk. 4
Never delay dual antiplatelet therapy—both aspirin and P2Y12 inhibitor must be given immediately in suspected stent thrombosis, as mortality risk from untreated thrombosis far exceeds bleeding concerns. 2
Anticoagulation Management
Start unfractionated heparin (UFH) bolus and infusion immediately for precise control in this unstable patient requiring emergent catheterization. 2, 5
Alternatively, low-molecular-weight heparin (enoxaparin) is acceptable if UFH is unavailable, though UFH is preferred when emergent PCI is imminent. 2, 5
Fondaparinux or bivalirudin are alternative options but UFH remains most practical for immediate catheterization. 5
Beta-Blocker Therapy for Ventricular Ectopy and Hypertension
Administer intravenous metoprolol 5 mg every 5 minutes for up to 3 doses to rapidly control heart rate, blood pressure, and suppress ventricular ectopy. Target heart rate 50-60 bpm. 1, 3
Beta-blockers reduce myocardial oxygen demand by decreasing heart rate and blood pressure, which is critical in ongoing ischemia with ventricular arrhythmias. 3
Avoid beta-blockers only if there are signs of acute decompensated heart failure, cardiogenic shock, or high-degree AV block. Given possible LV dysfunction, monitor closely but do not withhold if hemodynamically stable. 1
Transition to oral metoprolol once stabilized, titrating to target heart rate while monitoring for hypotension or bradycardia. 3
Nitroglycerin for Ongoing Chest Pain
Start intravenous nitroglycerin infusion immediately at 5-10 mcg/min, titrating upward every 3-5 minutes until chest pain resolves or blood pressure normalizes. 2
IV nitroglycerin is more effective than sublingual for symptom relief and regression of ST-segment changes in ongoing ischemia. 2
Do not give nitrates if phosphodiesterase-5 inhibitor (sildenafil, tadalafil) was taken within 24-48 hours due to severe hypotension risk. 2
Monitor blood pressure closely during titration; hypotension may indicate right ventricular involvement or hypovolemia. 2
Morphine for Refractory Pain
Administer morphine 2-4 mg IV if chest pain persists despite nitroglycerin, with additional doses every 5-15 minutes as needed. 1, 2
Be aware that morphine may slow intestinal absorption of oral antiplatelet agents, though this should not delay administration in severe pain. 2
ACE Inhibitor Initiation
Start an ACE inhibitor within 24 hours given hypertension and possible LV dysfunction. This is a Class I recommendation for patients with LVEF ≤40%, heart failure, hypertension, or diabetes. 1
Use agents and doses of proven efficacy (e.g., lisinopril 2.5-5 mg initially, ramipril 2.5 mg initially). 1
Use an ARB if ACE inhibitor is not tolerated (e.g., due to cough or angioedema). 1
High-Intensity Statin Therapy
Initiate high-intensity statin therapy immediately (atorvastatin 80 mg or rosuvastatin 40 mg daily) to reduce LDL cholesterol by ≥50%. 1, 5, 6
Statins should be started as early as possible after admission in all ACS patients unless contraindicated. 1
Oxygen Therapy
- Administer supplemental oxygen only if oxygen saturation <90% or if the patient has respiratory distress. Routine oxygen in non-hypoxemic patients is not beneficial. 1
Critical Timing: Emergent Coronary Angiography
This patient requires immediate coronary angiography within 2 hours given suspected stent thrombosis with ongoing chest pain, ventricular ectopy, and hemodynamic instability (hypertension may represent compensatory response). 2, 7
Suspected stent thrombosis is a very-high-risk feature requiring immediate invasive strategy, not delayed 12-24 hour approach. 2
Additional Considerations for Possible LV Dysfunction
If LVEF is confirmed ≤40% after stabilization, add mineralocorticoid receptor antagonist (eplerenone 25 mg daily, titrate to 50 mg) if no significant renal dysfunction or hyperkalemia. 1
Beta-blocker therapy becomes even more critical with reduced LVEF to reduce risk of death, recurrent MI, and heart failure hospitalization. 1
Common Pitfalls to Avoid
Do not withhold antithrombotic therapy due to bleeding concerns—the mortality risk from untreated stent thrombosis vastly exceeds bleeding risk. 2
Do not use fibrinolytic therapy—it is contraindicated and harmful in this scenario; immediate PCI is the only appropriate reperfusion strategy for suspected stent thrombosis. 2, 7
Do not delay dual antiplatelet therapy waiting for catheterization—both aspirin and ticagrelor must be given immediately. 2, 3
Do not use aspirin doses >100 mg maintenance when combining with ticagrelor, as higher doses increase bleeding without improving efficacy. 8
Do not assume beta-blockers are contraindicated with possible LV dysfunction—they are essential unless acute decompensated heart failure or cardiogenic shock is present. 1, 3