Lesson
ACS Pathophysiology and Presentation
Acute plaque disruption can couple platelet activation with thrombin and fibrin, but not every troponin elevation represents acute coronary thrombosis.
- Current and legacy MI categories
- Plaque rupture and erosion
- Myocardial injury
- Symptoms and acute danger
Expose collagen and tissue factor
Adhesion, signaling, and aggregation
Stabilize the growing clot
Time and collateral flow shape damage
Build the acute thrombus
Plaque rupture or erosion exposes thrombogenic material. Platelets adhere, activate, and aggregate while tissue factor drives thrombin and fibrin. The clot may partially or completely obstruct flow, embolize distally, or change over time. Antiplatelets and anticoagulants address complementary parts of this biology.
Connect supply, demand, and coronary flow
Myocardial oxygen demand rises with heart rate, contractility, and ventricular wall tension. Wall tension reflects pressure, chamber radius, and wall thickness. Left coronary perfusion occurs predominantly during diastole, so tachycardia can simultaneously increase demand and shorten perfusion time. Hypotension, anemia, hypoxemia, and elevated ventricular filling pressure can further reduce effective oxygen delivery.
Read older type 1 and type 2 terminology
In older classifications, type 1 MI reflects acute atherothrombosis. Type 2 MI includes ischemic injury from supply-demand imbalance without primary acute coronary thrombosis, such as severe anemia, hypoxemia, shock, tachyarrhythmia, or extreme pressure. Both require evaluation, but the treatment priorities differ.
Apply the 2026 classification
The Fifth Universal Definition groups MI as primary, secondary or procedure-related. Primary MI includes acute coronary atherothrombosis, dissection, spasm and embolism; it is broader than older type 1 MI. Confirm the mechanism with coronary and cardiac imaging when feasible. STEMI/NSTEMI describes the ECG presentation, not a guaranteed complete/partial blockage.
Confirm secondary MI rather than assuming it
An acute illness causing oxygen supply-demand imbalance can raise suspicion for secondary MI. Where appropriate and feasible, confirmation requires obstructive CAD without acute coronary pathology, or new ischemic regional dysfunction or loss of viable myocardium. Symptoms and troponin alone may be insufficient. Clinical judgment remains necessary when imaging is inappropriate or unavailable.
Separate injury from infarction
Acute myocardial injury requires a rise or fall in cardiac troponin with at least one value above the assay- and sex-specific 99th-percentile upper reference limit. A detectable value or change entirely below that limit does not by itself establish myocardial injury. MI additionally requires evidence of ischemia from symptoms, ECG, imaging, or coronary findings. Kidney disease, sepsis, heart failure, pulmonary embolism, myocarditis, and other disorders can elevate troponin without atherothrombotic MI.
Distinguish procedural injury from procedural infarction
A troponin rise after a cardiac procedure does not alone establish MI. The 2026 category concerns a coronary complication within 30 days. Confirmation uses a coronary complication and/or new ischemic regional dysfunction or loss of viable myocardium. Both are required when the complication occurs during the procedure or the procedure treats acute MI.
Use MINOCA as a working diagnosis
The 2026 definition expands MINOCA as myocardial injury with nonobstructive coronary arteries: possible MI with no coronary stenosis of 50% or greater. Investigate the cause rather than prescribing one universal regimen. Cardiac MRI may identify myocarditis, Takotsubo syndrome or infarction. If MI is confirmed, assign its mechanism-based category.
Recognize the full symptom spectrum
ACS can present with chest pressure, arm, shoulder, jaw, neck, back, or epigastric discomfort, dyspnea, diaphoresis, nausea, lightheadedness, fatigue, weakness, or palpitations. Teach emergency activation, not self-transport or watchful waiting. Time to reperfusion changes injury.
Quick check
Checking for saved practice…
Lesson
Rapid Diagnosis and Initial Stabilization
Emergency care obtains an ECG without delay, uses assay-specific serial troponin, treats hemodynamic and respiratory instability, and avoids therapies that worsen ACS mimics.
- Serial ECG
- High-sensitivity troponin
- Selective oxygen and nitrates
- Dangerous differentials
Activate emergency care
Repeat for persistent suspicion or changing symptoms
Identify acute myocardial injury
Choose reperfusion and antithrombotic strategy
Acquire and repeat the ECG
Obtain and interpret a 12-lead ECG within 10 minutes of first medical contact. A diagnostic STEMI pattern activates reperfusion without waiting for troponin. If the tracing is nondiagnostic but suspicion persists, repeat it during symptoms and consider posterior or right-sided leads based on the pattern.
Use the local high-sensitivity troponin pathway
Interpret concentration and change over serial samples using the validated assay-specific algorithm. Symptom timing, baseline kidney disease, prior values, sex-specific thresholds when used, and clinical probability matter. There is no single universal delta for every assay. If the initial result is nondiagnostic, repeat sampling is generally at 1-2 hours for high-sensitivity assays or 3-6 hours for conventional assays, measured from the initial sample; follow the validated local pathway.
Stabilize without ritual therapy
For ACS with oxygen saturation below 90%, provide supplemental oxygen to reach at least 90%. Routine oxygen at saturations of 90% or higher does not improve cardiovascular outcomes. Respiratory distress requires assessment and treatment of its cause, not automatic oxygen regardless of saturation. Nitroglycerin can relieve ischemic discomfort but requires adequate pressure and exclusion of recent PDE5 inhibitor or riociguat exposure, right-ventricular preload dependence, and other causes of hypotension.
Reserve opioids for refractory pain
Persistent ischemia needs urgent reperfusion assessment. IV morphine may be used for pain resistant to tolerated anti-ischemic therapy: 2-4 mg, repeated every 5-15 minutes if needed under monitoring. Watch breathing, sedation and pressure. Morphine and fentanyl can delay oral P2Y12 effects; do not use them simply to mask ongoing ischemia. Avoid nonaspirin NSAIDs for ischemic pain.
Protect against dangerous mimics
Aortic dissection, pulmonary embolism, pericarditis, myocarditis, stress cardiomyopathy, and sepsis can mimic ACS. Tearing pain, pulse or neurologic deficits, pleuritic or positional features, hypoxemia, fever, shock pattern, or discordant imaging should redirect evaluation. Fibrinolysis in dissection can be fatal.
Quick check
Checking for saved practice…
Lesson
Antiplatelet Selection and Transitions
Aspirin, P2Y12 inhibition, and parenteral anticoagulation target different elements of coronary thrombosis, while timing, PCI, CABG probability, kidney function, and bleeding define the regimen.
- Aspirin
- Ticagrelor, prasugrel, and clopidogrel
- Parenteral anticoagulation
- DAPT duration and bleeding
Suppress thromboxane signaling
Limit ADP-mediated platelet activation
Reduce thrombin generation or activity
Select agent, timing, and duration
Load aspirin rapidly
Aspirin irreversibly inhibits platelet COX-1 and suppresses thromboxane signaling. Unless contraindicated, give 162-325 mg of nonenteric-coated aspirin promptly, chewed when possible, including in patients already taking aspirin. Usual maintenance is 75-100 mg daily (commonly 81 mg), with later duration determined by the antithrombotic strategy. Review allergy phenotype, active bleeding, prior intracranial hemorrhage, and existing antithrombotics.
Choose the P2Y12 inhibitor around PCI and bleeding
Ticagrelor or prasugrel is preferred to clopidogrel for many PCI-treated STEMI and NSTE-ACS patients. Prasugrel is contraindicated with prior stroke or TIA. Age, weight, CABG probability, dyspnea, bradyarrhythmia, CYP interactions, adherence, cost, and bleeding can change selection.
Match clopidogrel loading to reperfusion
The 2025 ACS table uses 300 or 600 mg loading without fibrinolysis, then 75 mg daily. With STEMI fibrinolysis, give a 300-mg load through age 75; above 75, start 75 mg without loading. Continue 75 mg daily. These age cutoffs differ from enoxaparin adjustments, so check each medicine separately.
Protect clopidogrel activation
Clopidogrel needs CYP2C19 activation. Consider another P2Y12 inhibitor for known poor metabolizers after reviewing its contraindications. Avoid omeprazole/esomeprazole; separating doses by 12 hours does not solve the interaction. Choose suitable alternative gastroprotection when indicated. Avoid strong CYP2C19 inducers such as rifampin, which can increase active-metabolite exposure and bleeding.
Review clopidogrel safety beyond activation
Active pathological bleeding and product hypersensitivity contraindicate treatment. Repaglinide exposure increases; avoid the combination when possible. Watch for rare TTP with thrombocytopenia and hemolysis, sometimes accompanied by neurologic or renal findings. Interruption for major-bleeding-risk surgery is generally five days when possible, coordinated with the coronary team and a restart plan.
Dose ticagrelor across recovery
Load 180 mg; start 90 mg twice daily 6-12 hours later. If continuing beyond year one, use 60 mg twice daily. Aspirin maintenance is 75-100 mg when combined. Skip missed doses rather than doubling.
Screen ticagrelor safety and interactions
Prior intracranial hemorrhage, active pathological bleeding and hypersensitivity contraindicate use. Avoid severe hepatic impairment and strong CYP3A inhibitors/inducers. Assess dyspnea and bradyarrhythmias; do not independently stop treatment. Monitor digoxin levels. Avoid simvastatin/lovastatin above 40 mg/day and rosuvastatin above 20 mg/day; consider lower rosuvastatin doses when rhabdomyolysis risk is increased.
Dose prasugrel for the PCI pathway
For selected ACS patients managed with PCI, prasugrel is loaded at 60 mg, then usually 10 mg once daily. Consider 5 mg daily below 60 kg. Prior stroke/TIA, active pathological bleeding or product hypersensitivity contraindicates use. In NSTEMI, giving prasugrel before diagnostic angiography increases bleeding without demonstrated benefit.
Treat older age as a selection decision
The U.S. label generally discourages prasugrel at age 75 or older, except selected high-risk patients such as those with diabetes or prior MI. The 2025 ACS dosing table uses 5 mg maintenance with caution when treatment is selected at this age. A lower dose does not override contraindications or make routine use appropriate.
Coordinate surgery before prasugrel interruption
Do not initiate prasugrel when urgent CABG is likely. When interruption is possible, its label advises at least seven days before surgery. The coronary and surgical teams must balance urgency, bleeding and stent thrombosis; patients should not stop it independently.
Use IV cangrelor in the selected PCI setting
The labeled PCI population has received no P2Y12 inhibitor and is not receiving a GP IIb/IIIa inhibitor. Give 30 mcg/kg IV before PCI, then 4 mcg/kg/min for at least two hours or the procedure duration, whichever is longer. Significant active bleeding or hypersensitivity contraindicates treatment.
Plan the oral transition before stopping cangrelor
Platelet function recovers within about one hour. Give ticagrelor 180 mg during infusion or immediately afterward; clopidogrel 600 mg or prasugrel 60 mg must wait until immediately after stopping. Cangrelor interferes with the latter two drugs when given during infusion.
Use upstream treatment selectively
When NSTE-ACS angiography is planned more than 24 hours later, upstream clopidogrel or ticagrelor may be considered. When early anatomy is imminent, routine pretreatment can add bleeding and complicate CABG. Match timing to ischemic risk and diagnostic certainty.
Coordinate anticoagulation and DAPT
Use a syndrome and procedure-specific parenteral anticoagulant with renal, weight, and age adjustment. DAPT for at least 12 months is the default after ACS when bleeding risk is not high. PPI use, selected ticagrelor monotherapy after at least 1 month, and early aspirin discontinuation with long-term anticoagulation can reduce bleeding in appropriate patients.
Quick check
Checking for saved practice…
Lesson
Anticoagulant Dosing and PCI Handoff
Select and monitor acute anticoagulation using the syndrome, age, renal function, body weight and procedural timeline.
- UFH dose caps
- Renal and age adjustments
- Procedural supplementation
- Fondaparinux PCI restriction
Reconstruct prior exposure
Apply the correct regimen and limits
Use agent-appropriate monitoring
Confirm the next dose with the receiving team
Separate initial UFH from procedural dosing
For initial ACS therapy or with fibrinolysis, the 2025 guideline uses UFH 60 units/kg IV, capped at 4,000 units, then 12 units/kg/hour, initially capped at 1,000 units/hour. Titrate to the therapeutic monitoring protocol. PCI uses ACT-guided dosing; without prior anticoagulation, the initial bolus is 70-100 units/kg. Do not carry an upstream dose into the catheterization lab without reviewing prior exposure and ACT.
Apply both UFH dose caps
For a 90-kg patient starting the initial ACS regimen: 60 × 90 = 5,400 units, capped at 4,000; 12 × 90 = 1,080 units/hour, initially capped at 1,000. If the prepared infusion is 100 units/mL, start at 10 mL/hour. Verify the actual bag concentration and reassess subsequent titration from laboratory results.
Use bivalirudin with renal-aware infusion dosing
For PCI, give 0.75 mg/kg IV then 1.75 mg/kg/hour. Check ACT five minutes after the bolus; an additional 0.3 mg/kg bolus may be needed. Renal impairment does not reduce the initial bolus. Reduce infusion to 1 mg/kg/hour for Cockcroft-Gault CrCl below 30 mL/min, or 0.25 mg/kg/hour during hemodialysis. Active major bleeding or hypersensitivity contraindicates treatment.
Plan bivalirudin beyond the procedure
For STEMI primary PCI, the 2025 guideline recommends a 2-4-hour post-PCI infusion; preserve necessary renal adjustment. Monitor for bleeding and early stent thrombosis. Bivalirudin is an option during PCI in patients with HIT; substituting another heparin product does not address HIT. Confirm infusion concentration, compatibility and handoff before transfer.
Dose enoxaparin by syndrome and kidney function
For NSTE-ACS, use 1 mg/kg subcutaneously every 12 hours; CrCl below 30 mL/min changes this to every 24 hours. Do not substitute a prophylaxis dose.
Apply the separate STEMI age pathway
Below age 75, give 30 mg IV plus 1 mg/kg subcutaneously, then 1 mg/kg every 12 hours; cap the first two subcutaneous doses at 100 mg. At age 75 or older, omit the IV bolus and use 0.75 mg/kg every 12 hours, capping the first two doses at 75 mg. With CrCl below 30, use 1 mg/kg every 24 hours at either age; retain the 30-mg bolus only below 75.
Check monitoring and procedural handoff
Follow platelets, hemoglobin, renal function and bleeding. PT/aPTT cannot measure enoxaparin effect reliably; anti-Xa testing may help selected cases. Before PCI, verify dose history and timing to determine supplemental IV dosing rather than repeating a full regimen.
Verify supplemental enoxaparin before PCI
For a STEMI patient proceeding to PCI, the Lovenox label uses no additional dose if the last subcutaneous dose was less than eight hours before balloon inflation; after more than eight hours, give 0.3 mg/kg IV. Verify exact timing and the catheterization protocol, including single-dose exposure or boundary cases. For 80 kg, 0.3 × 80 = 24 mg, not 0.3 mg total.
Select fondaparinux for the appropriate pathway
The 2025 guideline permits fondaparinux 2.5 mg subcutaneously daily for NSTE-ACS when early invasive treatment is not anticipated. In selected STEMI fibrinolysis without an intended invasive approach, its alternative regimen is 2.5 mg IV initially, then 2.5 mg subcutaneously daily from the next day. ACS use is outside U.S. Arixtra labeled indications.
Change anticoagulant support when PCI becomes necessary
Fondaparinux alone is unsuitable for PCI because of catheter thrombosis. Communicate the last dose and renal function; the catheterization team must provide a procedural anticoagulant such as UFH. Do not simply give extra fondaparinux.
Screen fondaparinux safety and monitoring
Avoid with CrCl below 30 mL/min, active major bleeding, bacterial endocarditis, serious hypersensitivity or fondaparinux-associated antibody-positive thrombocytopenia. Follow renal function, CBC and bleeding; effects persist longer with renal impairment. PT/aPTT cannot establish adequate activity. If needed, anti-Xa testing requires fondaparinux calibration.
Quick check
Checking for saved practice…
Lesson
Reperfusion and Invasive Strategy
STEMI requires immediate artery-opening care, while NSTE-ACS invasive timing follows instability, ischemic risk, comorbidity, and whether further noninvasive stratification is appropriate.
- Primary PCI
- Selected fibrinolysis
- Immediate unstable NSTE-ACS angiography
- Risk-guided stable NSTE-ACS care
Contact-to-device goal: 90 min; transfer: 120 min
Screen exclusions; transfer immediately after lysis
Recurrent ischemia, shock, HF, or electrical instability
Match timing to ischemic and procedural risk
Build a primary-PCI system for STEMI
For STEMI within 12 hours, target first medical contact to device activation within 90 minutes, or 120 minutes when transfer is required. These are system targets, not permission to wait. Shock or hemodynamic instability requires emergency culprit revascularization regardless of symptom duration.
Use fibrinolysis only in the selected pathway
When timely primary PCI cannot be achieved, selected early-presenting STEMI patients without contraindications may receive fibrinolysis. Screen for prior intracranial hemorrhage, stroke timing, active bleeding, severe hypertension, recent surgery, anticoagulants, and dissection. Give adjunctive therapy, assess reperfusion, and transfer for rescue or routine angiography.
Choose reperfusion from the clock and contraindications
At a non-PCI hospital, STEMI symptoms under 12 hours with anticipated contact-to-device delay over 120 minutes support fibrinolysis if no contraindication exists. Transfer for PCI when fibrinolysis is contraindicated. At 12-24 hours, favor PCI transfer; late fibrinolysis is an exceptional consideration for ongoing symptoms with instability or substantial myocardium at risk when PCI is unavailable.
Continue care after fibrinolysis
Transfer immediately to a PCI center. Persistent ischemia, inadequate ST resolution or electrical/hemodynamic instability suggests failed reperfusion and calls for immediate angiography with rescue PCI. Otherwise, plan angiography within 2-24 hours with PCI when indicated.
Understand the fibrinolytic regimen
Fibrinolytics promote conversion of fibrin-bound plasminogen to plasmin and accelerate fibrin degradation. Tenecteplase for STEMI is administered as a single weight-tiered intravenous bolus, with a maximum of 50 mg. Alteplase uses a weight-based infusion regimen, with a maximum total dose of 100 mg. The selected product, adjunctive antithrombotics, age, weight, bleeding risk, and transfer plan must be verified from the current protocol and prescribing information before administration.
Identify absolute STEMI fibrinolysis exclusions
Exclude prior intracranial hemorrhage, cerebral vascular malformation, malignant intracranial tumor, ischemic stroke within three months, suspected aortic dissection, active bleeding/bleeding diathesis, significant head/facial trauma within three months, and intracranial/intraspinal surgery within two months. Ordinary menstruation is not the bleeding exclusion. Blood pressure above 180 systolic or 110 diastolic that remains uncontrolled despite therapy also excludes fibrinolysis. Apply additional product restrictions.
Separate relative risks from automatic exclusions
Individualize assessment for remote ischemic stroke, dementia or other intracranial disease, poorly controlled hypertension, traumatic or prolonged CPR over ten minutes, major surgery within three weeks, internal bleeding within two to four weeks, noncompressible punctures, pregnancy, active peptic ulcer and oral anticoagulants. Elevated presenting pressure requires treatment and reassessment. These findings do not grant permission to treat; weigh bleeding against reperfusion benefit and PCI access.
Read the tenecteplase indication before the dose
The U.S. STEMI label uses one IV bolus over five seconds: 30 mg below 60 kg; 35 mg at 60 to under 70 kg; 40 mg at 70 to under 80 kg; 45 mg at 80 to under 90 kg; 50 mg at 90 kg or more. At 5 mg/mL, an 82-kg patient receives 45 mg / 5 mg/mL = 9 mL. Stroke dosing is different; never interchange order sets.
Distinguish labeled dosing from an older-adult protocol
The U.S. TNKase STEMI label lists full weight-based doses without an age-based reduction. The 2025 Australian ACS guideline describes age-adjusted half-dose tenecteplase, supported by bleeding data in patients aged 75 and older. Reduced dosing does not eliminate intracranial hemorrhage. Confirm which specialist-approved STEMI protocol applies, including adjunctive antithrombotic doses; do not substitute the stroke order set merely because the milligram dose looks similar.
Calculate the accelerated alteplase regimen
The AMI label uses a 15-mg IV bolus, then 50 mg over 30 minutes and 35 mg over 60 minutes above 67 kg. At 67 kg or less, the two infusions are 0.75 mg/kg and 0.50 mg/kg; total dose must not exceed 100 mg. For 60 kg: 15 + 45 + 30 = 90 mg over the bolus and 90-minute infusion sequence. At 1 mg/mL, infusion rates are 90 mL/hour for the first 30 minutes and 30 mL/hour for the next hour. Check the approved local order set and concentration independently.
Compare product contraindications explicitly
Do not merge product labels into one vague recent-surgery rule. TNKase excludes intracranial/intraspinal surgery or trauma within two months; Activase uses three months for intracranial/intraspinal surgery or serious head trauma. Both require bleeding, blood-pressure and intracranial-pathology screening. Apply the STEMI guideline and exact product restrictions together; a shorter interval from another product is not clearance to treat.
Keep reteplase units and line compatibility distinct
For STEMI, reteplase is given as 10 units IV over two minutes, followed by another 10 units 30 minutes later. Reconstitution yields 1 unit/mL, so each dose is 10 mL. These are product-specific units, not milligrams. Do not administer through a line containing heparin or simultaneously with other medicines. Withhold the second dose if serious bleeding or an anaphylactoid reaction develops; urgently treat the complication.
Resolve the alteplase weight boundary explicitly
At exactly 67 kg, the manufacturer label and the 2025 ACS guideline table use different cutoffs: the label retains weight-based infusions, while the guideline table places 67 kg in the fixed 100-mg regimen. This lesson identifies the label regimen rather than silently merging the tables. Verify the institutional STEMI order set with pharmacy; do not round weight to choose a different regimen.
Take unstable NSTE-ACS immediately
Refractory or recurrent ischemia, hemodynamic or electrical instability, acute pulmonary edema or heart failure, or worsening mechanical findings supports immediate invasive evaluation. Transfer immediately when a non-PCI center cannot provide the required care.
Risk-stratify stable NSTE-ACS
Intermediate- and high-risk patients who are suitable revascularization candidates should undergo an invasive approach during hospitalization. For stable high-risk patients, angiography within 24 hours is reasonable. Low-risk patients can use routine or selective invasive evaluation with further risk stratification. Troponin, ECG, GRACE or TIMI when appropriate, diabetes, age, kidney disease, bleeding, frailty, preference, and life expectancy shape timing.
Quick check
Checking for saved practice…
Lesson
PCI, Complete Revascularization, and Shock
Access, intravascular imaging, nonculprit disease, CABG versus PCI, and shock strategy determine how reperfusion is delivered beyond the first lesion.
- Radial access
- Intravascular imaging
- Complete revascularization
- Culprit-only acute shock PCI
Reduce bleeding and vascular complications
Guide complex lesion PCI
Stage or complete according to stability and anatomy
Avoid routine immediate nonculprit PCI
Reduce procedural harm
Radial access is preferred over femoral access for most ACS PCI because it reduces bleeding and vascular complications and improves outcomes. IVUS or OCT is recommended to guide left-main or complex-lesion stenting. Intravascular imaging helps size vessels, characterize complex lesions, optimize stent expansion and apposition, and identify edge or deployment problems.
Plan complete revascularization
Significant nonculprit disease should be addressed in appropriate STEMI and NSTE-ACS patients. Same-setting or staged PCI and CABG depend on stability, lesion significance, coronary complexity, diabetes, ventricular function, kidney disease, surgical risk, contrast burden, and preference.
Treat the culprit first in shock
In ACS with cardiogenic shock, emergency culprit-vessel revascularization is indicated. Routine PCI of non-infarct arteries during the same shock procedure is not recommended. Restore flow with the least additional procedure burden, then reassess other disease after stabilization.
Use support selectively
A microaxial flow pump can be reasonable in selected STEMI patients with severe or refractory cardiogenic shock, but bleeding, limb ischemia, and renal failure are increased. Shock-team selection, vascular access, perfusion goals, mechanical-complication assessment, and a deliberate weaning plan are essential.
Quick check
Checking for saved practice…
Lesson
Discharge, Secondary Prevention, and Recovery
The transition after ACS must preserve antithrombotic protection, rapidly reduce atherogenic exposure, identify ventricular and rhythm complications, restore function, and close access gaps.
- Bleeding mitigation
- Lipid intensification
- Ventricular and complication care
- Rehabilitation and follow-up
Document each drug and planned stop date
Start intensive prevention in hospital
Restore confidence and capacity
Close gaps in exposure and goals
Protect DAPT while reducing bleeding
Record each drug, its planned duration and who may change it. For ACS requiring oral anticoagulation, discontinue aspirin after 1-4 weeks of triple therapy while continuing the anticoagulant and preferably clopidogrel. Select timing from bleeding and stent-thrombosis risk. Provide a PPI when GI bleeding risk is high.
Distinguish shortening from stopping protection
After tolerated ticagrelor-based DAPT, ticagrelor alone from at least one month after PCI reduces bleeding. Switching to clopidogrel or shortening to single antiplatelet therapy in high-bleeding-risk PCI patients are separate, selected strategies. Do not generalize these pathways to every medically managed ACS patient or stop all antithrombotics.
Intensify lipids in the hospital
Start high-intensity statin therapy for ACS and consider concurrent ezetimibe when appropriate. Add a nonstatin when maximally tolerated therapy leaves LDL-C above current high-risk thresholds or goals. Arrange a fasting lipid panel 4 to 8 weeks after initiation or dose adjustment and assign ownership for action.
Write the lipid goal explicitly
Use the 2026 secondary-prevention goals: LDL-C below 55 mg/dL and non-HDL-C below 85 mg/dL for very-high-risk ASCVD; other clinical ASCVD generally has an LDL-C goal below 70 mg/dL. Document the risk category, baseline and achieved concentrations, treatment tolerance and interaction limits. A substantial percentage reduction does not necessarily mean the absolute goal has been reached.
Address ventricular and mechanical consequences
Assess LVEF, heart failure, arrhythmias, conduction, mitral regurgitation, ventricular septal or free-wall complications, pericarditis, kidney injury, anemia, and access-site injury. Beta blockers, RAAS therapy, mineralocorticoid antagonists, SGLT2 inhibitors, defibrillator timing, and diuretics depend on the resulting phenotype.
Start oral beta blockade when stable
Begin a low oral dose within 24 hours if there is no contraindication. Defer with acute heart failure, low output or shock risk, severe bradycardia, important conduction disease without pacing, or active bronchospasm; reassess after stabilization. Routine IV treatment before primary PCI is not recommended. Long-term need depends on ventricular function and other indications, rather than an automatic three-year course.
Choose RAAS therapy from the clinical phenotype
An ACE inhibitor or ARB is indicated with LVEF at or below 40%, hypertension, diabetes or anterior STEMI; it is reasonable in other suitable ACS patients. Do not combine ACE inhibitor and ARB. With LVEF at or below 40% plus heart-failure symptoms or diabetes, assess eligibility for an MRA.
Separate MRA eligibility from label contraindications
For symptomatic HFrEF, guideline initiation requires eGFR above 30 mL/min/1.73 m² and potassium below 5.0 mEq/L. Eplerenone labeling separately contraindicates CrCl at or below 30, potassium above 5.5 at initiation, and strong CYP3A inhibitors. The label threshold is not permission to ignore the stricter guideline initiation criteria. eGFR and CrCl are different estimates.
Give eplerenone a monitoring plan
In stable post-MI symptomatic HFrEF, start 25 mg daily and titrate toward 50 mg daily within four weeks as tolerated. Check potassium before starting, within the first week, at one month after initiation or dose adjustment, and periodically thereafter. Moderate CYP3A inhibitors limit the post-MI dose to 25 mg daily. Adjust or withhold according to potassium; assign responsibility for reviewing results.
Anticipate remodeling and early complications
Infarct size, location, reperfusion delay, and residual ischemia influence ventricular remodeling. Watch for cardiogenic shock, acute heart failure, recurrent ischemia, ventricular or atrial arrhythmias, bradycardia, conduction block, papillary muscle dysfunction, septal rupture, and free-wall rupture. A new murmur, abrupt pulmonary edema, recurrent hypotension, rising lactate, or electrical instability requires immediate reassessment rather than routine discharge planning.
Escalate suspected structural failure
New shock, pulmonary edema or a murmur after MI warrants urgent assessment for septal rupture, acute mitral regurgitation from papillary muscle injury, or free-wall rupture. Involve a center with cardiac surgical expertise. Temporary circulatory support may bridge selected patients to repair; it does not replace definitive evaluation. The Heart Team determines intervention timing from anatomy, instability and tissue integrity.
Separate ICD prevention from urgent arrhythmia care
For primary prevention, reassess after recovery and medical therapy: generally at least 40 days after MI and 90 days after revascularization. Eligibility also depends on LVEF, symptoms, electrophysiologic findings when relevant and expected survival. A low early LVEF alone is not an automatic immediate implant indication. Sustained ventricular arrhythmias or persistent high-grade block need urgent specialist assessment through separate pathways.
Investigate possible LV thrombus
Large anterior infarction and marked LV dysfunction increase risk. Begin with echocardiography; consider cardiac MRI when suspicion remains despite inconclusive echo. A negative early study does not exclude later thrombus formation. Confirmed post-MI LV thrombus commonly warrants about three months of anticoagulation, followed by repeat imaging to determine whether treatment should continue. Coordinate antiplatelet overlap and bleeding risk.
Recognize post-MI pericarditis without missing recurrent ischemia
New chest pain requires reassessment. Early post-MI pericarditis may settle with supportive care; persistent or later symptoms may need high-dose aspirin and colchicine after contraindication and interaction review. Nonaspirin NSAIDs and glucocorticoids can impair healing or increase harm. An asymptomatic effusion alone does not justify routine anti-inflammatory treatment.
Build recovery before discharge
Refer to cardiac rehabilitation, including home-based options when attendance is difficult. Reconcile every medicine, confirm acquisition and affordability, teach nitroglycerin and emergency symptoms, address tobacco and mental health, explain activity and work plans, and arrange early cardiology and primary-care follow-up.
Quick check
Checking for saved practice…
Module practice
Check the connections.
Each attempt draws 10 questions from the complete 123 question bank.
Each attempt draws a fresh set and rearranges the answer choices.
References
Current clinical foundation.
Core source material was synthesized with the following contemporary guidance. Verify local policy and current guidance before applying clinical information.
- AHA. 2026 Dyslipidemia Guideline: secondary-prevention goals
- DailyMed. Inspra prescribing information, June 2025
- AHA/ACC/HFSA. 2022 Heart Failure Guideline slide set
- DailyMed. Arixtra prescribing information
- Sanofi. Lovenox prescribing information, May 2025
- DailyMed. Bivalirudin prescribing information
- DailyMed. Clopidogrel prescribing information
- Heart Foundation/CSANZ. 2025 ACS guideline: reperfusion and older-adult fibrinolytic dosing
- DailyMed. Retavase prescribing information
- Genentech. TNKase prescribing information
- Genentech. Activase prescribing information
- FDA. Brilinta prescribing information, May 2026
- DailyMed. Kengreal prescribing information
- DailyMed. Prasugrel dosing, timing and bleeding restrictions
- ESC/ACC/AHA/WHF. Fifth Universal Definition (2026), full consensus
- AHA and ACC. 2025 Acute Coronary Syndromes Guideline
- American Heart Association. 2025 ACS Top Things to Know
- American College of Cardiology. 2025 ACS Guideline Hub
- AHA, ACC, ESC, and WHF. 2026 Universal Definition of Myocardial Infarction
- AHA and ACC. 2026 Dyslipidemia Guideline
- DailyMed. TNKase prescribing information
- DailyMed. Activase prescribing information