What is the likely diagnosis and immediate management for a patient with coronary artery disease who underwent PCI (percutaneous coronary intervention) to the left anterior descending artery for a 100% occlusive atheroma and, one hour after stent placement, develops tachycardia, hypotension, profuse sweating, and left‑sided chest pain?

Acute Stent Thrombosis with Cardiogenic Shock

This patient is experiencing acute stent thrombosis presenting as STEMI with cardiogenic shock and requires immediate return to the catheterization laboratory for emergent coronary angiography and thrombectomy. 1

Immediate Recognition and Diagnosis

The clinical presentation of tachycardia, hypotension, profuse diaphoresis, and left-sided chest pain occurring one hour after LAD stenting is pathognomonic for acute stent thrombosis with cardiogenic shock. 2, 1 This represents a Type 4b myocardial infarction according to the Universal Definition—post-PCI MI caused by coronary stent thrombosis. 2

• Obtain a 12-lead ECG immediately (within 10 minutes) to identify new ST-segment elevation in anterior leads, which would confirm acute LAD occlusion from stent thrombosis. 2, 1
• The hemodynamic instability (hypotension with tachycardia) combined with chest pain indicates cardiogenic shock from acute loss of anterior wall myocardium. 2
• Early stent thrombosis (occurring within 24 hours) carries in-hospital mortality rates of 2-4% and significantly higher rates of cardiogenic shock. 3

Emergent Catheterization Laboratory Activation

Activate the cardiac catheterization laboratory immediately without any delay—this is a Class I, Level A indication for emergent coronary angiography. 1, 2

• Transfer the patient directly to the catheterization laboratory, bypassing any intermediate care areas. 4
• Administer unfractionated heparin or bivalirudin during transport to maintain therapeutic anticoagulation. 1
• Ensure continuous cardiac monitoring with defibrillator immediately available, as ventricular arrhythmias occur in 2.6-5.7% of acute MI patients. 5

Immediate Pharmacotherapy During Transport

Verify dual antiplatelet therapy status immediately—premature discontinuation of DAPT is the most common cause of acute stent thrombosis. 1, 2

• Confirm the patient received aspirin 162-325 mg and a loading dose of a P2Y12 inhibitor (clopidogrel 600 mg, prasugrel 60 mg, or ticagrelor 180 mg) at the time of initial PCI. 2, 1
• If DAPT was not adequately loaded, administer appropriate loading doses immediately. 2
• Consider intracoronary glycoprotein IIb/IIIa inhibitor (eptifibatide or abciximab) during repeat PCI, as lower use of GP IIb/IIIa inhibitors is associated with higher rates of early stent thrombosis. 3, 6

Catheterization Laboratory Management

Perform immediate thrombectomy and/or balloon angioplasty of the thrombosed stent, with consideration of additional stent placement only if there is evidence of stent underexpansion or malapposition. 1, 3

• Manual thrombus aspiration should be performed to restore TIMI 3 flow and prevent distal embolization. 2
• Intravascular ultrasound (IVUS) imaging should be strongly considered to identify stent malapposition or uncovered plaque, which are found in approximately 55% of early stent thrombosis cases. 3
• Administer intracoronary GP IIb/IIIa inhibitor (eptifibatide 180 mcg/kg bolus followed by 2 mcg/kg/min infusion for 18-24 hours) to prevent re-thrombosis. 6

Cardiogenic Shock Management

For patients presenting with cardiogenic shock, complete revascularization of all significantly diseased vessels should be considered during the emergency procedure, as this may be life-saving. 2

• Initiate inotropic support (dobutamine or milrinone) if systolic blood pressure remains <90 mmHg despite volume resuscitation. 2
• Consider mechanical circulatory support (intra-aortic balloon pump or Impella) if hemodynamic instability persists after successful revascularization. 2
• Critical caveat: Be aware that IABP can paradoxically worsen hemodynamics in patients who develop dynamic left ventricular outflow tract obstruction—if the patient deteriorates after IABP insertion, obtain urgent echocardiography to evaluate for systolic anterior motion of the mitral valve. 7

Post-Procedure Intensive Monitoring

Continue uninterrupted cardiac monitoring for a minimum of 24-48 hours, as 80-92% of ventricular arrhythmias occur within 48 hours of PCI. 2, 5

• Maintain the patient NPO until acute stent thrombosis and need for urgent repeat angiography have been definitively excluded. 1
• Perform urgent echocardiography to assess left ventricular function, identify mechanical complications (free wall rupture, ventricular septal defect, acute mitral regurgitation), and exclude left ventricular thrombus. 4
• Monitor for signs of "no-reflow" phenomenon (persistent chest pain despite TIMI 3 flow), which is associated with reduced survival and may require intracoronary vasodilators (adenosine, verapamil, or nitroprusside). 2

High-Risk Features in This Case

This patient has multiple high-risk features that increase mortality: 100% LAD occlusion (anterior wall territory), triple-vessel disease, and presentation with cardiogenic shock. 1, 2

• Anterior wall infarction from LAD occlusion carries the highest risk of pump failure and mechanical complications. 1
• The presence of triple-vessel disease suggests extensive atherosclerotic burden and higher likelihood of incomplete revascularization. 1
• Early stent thrombosis occurring within one hour suggests either inadequate antiplatelet therapy, stent underexpansion, or uncovered atheroma at the stent edges. 3, 8

Critical Pitfalls to Avoid

Do NOT delay catheterization for any reason—every minute of delay increases myocardial necrosis and mortality risk. 4

• Do NOT administer beta-blockers in the setting of cardiogenic shock, as this will worsen hemodynamic instability. 5
• Do NOT assume the patient is adequately anticoagulated—acute stent thrombosis can occur despite therapeutic anticoagulation if antiplatelet therapy is inadequate. 1
• Do NOT attribute hypotension solely to vasovagal reaction or sedation—assume stent thrombosis until proven otherwise. 2
• Do NOT delay transfer to a PCI-capable center if the initial procedure was performed at a non-PCI facility. 4

Post-Resuscitation DAPT Management

Ensure a minimum of 12 months of uninterrupted dual antiplatelet therapy with aspirin plus a potent P2Y12 inhibitor (ticagrelor or prasugrel preferred over clopidogrel). 4, 1

• Premature discontinuation of DAPT markedly raises the risk of recurrent stent thrombosis and is the most common preventable cause. 2, 1
• Add a proton pump inhibitor if the patient has high gastrointestinal bleeding risk. 4
• Consider platelet function testing to ensure adequate P2Y12 inhibition, particularly if clopidogrel is used (due to variable metabolism). 2