Published October 2023
Author(s): Samantha Coffer Thielen, MD1; Sarah Slaven, MD2; Joseph Burke, MD3
Executive editor(s): Yilin Zhang, MD4; Brandon Fainstad, MD5
1Resident, Department of Medicine, University of Colorado
2Fellow, Department of Medicine, Division of Cardiology, University of Colorado
3Assistant Professor, Department of Medicine, Division of Cardiology, University of Colorado
4Assisstant Professor, Department of Medicine, University of Washington – Valley Medical Center
5Associate Professor, Department of Medicine, University of Colorado
- Select appropriate early medical interventions to address oxygenation, pain, antiplatelet and anticoagulation therapy in patients presenting with acute coronary syndrome (ACS).
- Determine timing of revascularization in STEMI versus NSTEMI with and without high-risk features.
- Select appropriate medical therapies for ACS to initiate prior to discharge based on ACS-type, revascularization methods and patient comorbidities.
Plan to spend at least 30-60 minutes preparing for this talk by reviewing the teaching script and clicking through the graphic animations on the Interactive Board to become familiar with the flow and content of the talk. Print out copies of the Learner’s Handout so learners may take notes as you expand on management and apply it through practice cases. Begin with reviewing the objectives for the session. All clickable elements are indicated by a cursor icon.
The anticipated time to deliver this talk is about 20-25 min without cases and 35-45 min with cases.
The talk can be presented in 2 ways:
- Project the “Interactive Board” OR
- Reproduce your own drawing of the presentation on a whiteboard
Objective 1: Select appropriate early medical interventions to address oxygenation, pain, antiplatelet and anticoagulation therapy in patients presenting with acute coronary syndrome (ACS) (Early Tx)
The early management of patients presenting with ACS is the same regardless of ACS-type (STEMI, NSTEMI, or unstable angina). Initial therapies should be aimed at addressing stabilizing vital signs (e.g., addressing hypoxia and hypotension), pain control, and antiplatelet and anticoagulant management.
Click on each of the letters on the timeline to reveal the medications below.
Supplemental O2 in patients with STEMI without hypoxemia may be harmful (AVOID trial, 2015)
Anticoagulation and Antiplatelet Therapy
Anticoagulant of choice for use peri-procedure because of quick on/off
Medical management of NSTEMI (no plan for revascularization)
Reduces death, MI, recurrent angina at 14 days (versus heparin) in medical management of NSTEMI (ESSENCE trial, 1997)
If persistent angina after 3 doses, can escalate to IV nitroglycerin drip
Increases mortality and may mask refractory angina
GP IIb/IIIa inhibitor (eptifibatide)
Objective 2: Determine timing of revascularization in STEMI versus NSTEMI with and without high risk features (PCI)
STEMI: Patients presenting with STEMI should undergo immediate revascularization.
- At PCI capable hospitals, the goal is to undergo PCI within 90 minutes (assuming symptom onset is <12 hours). Door to balloon time begins when the patient comes through the doors of the hospital until balloon angioplasty of culprit vessel. Time is myocardium! The goal of quick blood restoration is to prevent permanent myocardial damage in the territory of the culprit vessel which could result in reduced ejection fraction and HF.
- At non-PCI capable hospitals, the goal then shifts to transferring patients to a PCI-capable hospital.
- Transfer should occur to PCI capable hospital if this can occur <120 min.
- If there is no PCI capable hospital within 120 min, then fibrinolytics should be given within 90 min. Multiple RCTs and meta-analyses demonstrate PCI is superior to fibrinolytics. Fibrinolytics do not achieve perfusion in 35% of patients and are also associated with higher rates of death, MI, CVA, and major bleeding, therefore this strategy should only be used only if transfer to PCI capable hospital door to balloon time is >120 minutes.
- Delayed angiography with possible PCI (3-24 hours) should be pursued after fibrinolytic therapy since fibrinolytics often does not achieve reperfusion, especially if recurrent symptoms or ECG changes.
- There are some situations where PCI is not possible due to anatomy, in these cases emergent CABG can be considered as a primary reperfusion strategy if there is ongoing ischemia and large myocardial territory at risk.
- If symptom onset was >12 hours, PCI is typically still pursued unless there is a totally occluded infarct and there are no ongoing symptoms of ischemia.
NSTEMI: Two main approaches exist for treating non-ST elevation MI (NSTEMI). Invasive strategy vs. ischemia guided strategy. The invasive strategy includes patients undergoing diagnostic angiography with intent to revascularize prior to hospital discharge. The alternative, ischemia guided strategy, treats medically and only recommends invasive evaluation with angiography for those who fail medical therapy (refractory angina), have objective evidence of ischemia (dynamic EKG changes, perfusion defect) or have clinical indicators of high prognostic risk. Routine use of the invasive strategy is associated with improved outcomes (lower composite death, MI or refractory angina at 4-6 months). However, ischemia guided strategy can be considered as an approach in very low risk patients per AHA/ACC guidelines.
Click on “risk stratification”. The timing of revascularization first requires risk stratification. Some very high-risk features clinical features require urgent revascularization. The GRACE and TIMI scores can be used to help determine risk of death within 90 days (GRACE) or all-cause mortality at 14 days (TIMI) based on individual risk factors and presenting features. Click on “GRACE” and “TIMI” to open each respective calculator. You may choose to review the clinical features and comorbidities included in each risk score.
- Immediate PCI -urgent/immediate revascularization within 2 h is indicated for patients with very high-risk features such as:
- Cardiogenic shock [SHOCK 1999]
- Hemodynamic instability (MR or VSD)
- Angina despite max medical therapy – take chest pain seriously, treat as able with nitroglycerin, but once maximized therapy, must revascularize. Ongoing pain = ongoing ischemia.
- Unstable arrhythmia (VT/Vfib)
- High risk – early invasive revascularization <24 hours is indicated for high risk patients such as:
- GRACE >140 or elevated TIMI scores 6-7
- Age >75
- Elevated cardiac biomarkers
- New ST depression
- Moderate to low risk – delayed invasive revascularization at 25-72 hours (preceded by initial medical management) can be considered in GRACE 109-140 or TIMI 3-5. In this group a delayed strategy (25-72 hours rather than <24 hours) showed no difference in mortality.
- Very low risk – ischemia-guided strategy can be considered for very low risk patients per patient or clinician preference in the absence of high risk features.
- Very low risk features: GRACE <109 or TIMI 0 or 1
- Medical management, only pursue invasive diagnostic angiography if:
- Failed medical therapy (refractory angina
- Objective evidence of ischemia (dynamic ECG changes, perfusion defect
- Clinical indicators of high prognostic risk
Revascularization should not be delayed for patients who require emergent or urgent PCI for initiation of medical management.
Objective 3: Select appropriate medical therapies for ACS to initiate prior to discharge based on ACS-type, revascularization methods and patient comorbidities (Late Tx)
Management of early therapies
Continued as needed
81 mg daily should be continued as part of dual antiplatelet therapy (DAPT) post-PCI or in patients with CAD
If triple therapy (anticoagulation + DAPT) if needed, some patients may be able to stop aspirin after a period of time to decrease risk of bleeding
· If PCI → often stopped immediately after successful revascularization, though may be continued if large thrombus burden visualized during coronary angiography
· If no PCI in NSTEMI → continue anticoagulation for 48 h
· Initiated within 24 h (if not contraindications)
· Continued through discharge
· PRN nitroglycerin can be continued at discharge
· GP IIa/IIIb may be initiated or continued post-PCI in patients with high thrombosis burden for a period of time
STEMI and NSTEMI – initiate prior to hospital discharge if LVEF <40%, HF, or diabetes
Take Home Points
- Patients presenting with STEMI to PCI-capable hospital should undergo emergent revascularization within 90 minutes. If non-PCI capable hospital transfer to PCI capable hospital if PCI is possible within <120 minutes. If not, use fibrinolytics if no contraindications, then transfer for delayed angiography.
- Patients presenting with NSTEMI should be risk stratified into very high risk, high risk, moderate to low, or very low risk categories using TIMI/GRACE scores or clinical features. Patients with very high risk and high risk features should undergo immediate and early revascularization, respectively.
- In general aspirin, anticoagulation and pain management (including beta-blocker) should occur immediately if there are no contraindications, but not to delay emergent revascularization in patients with STEMI and very high risk NSTEMI. Statin and P2Y12 inhibitor should be added within 24 hours. ACE inhibitor/ARB and MRA should be added prior to discharge (after revascularization) if indicated.