ACS and Secondary Prevention of MI

What is a classic symptom of ACS?

Mid-line chest discomfort

What is important to consider when selecting drug therapy in ACS?

Avoiding drugs that are negative inotropes (ex: IV beta blockers) = can cause HF/shock

Monitoring BP to avoid hypotension = can cause shock

What are signs of acute HF/cardiogenic shock?

S3 heart sounds

Rales

Elevated jugular venous distention

Hypotension BP if cardiogenic shock

For exam purposes, what is hypotension defined as?

SBP < 100 mmHg

How can a 12-lead ECG diagnose MI?

ST-segment elevation

ST-segment depression

T wave inversion

No ST-T wave changes

How can troponin levels diagnose MI?

Type 1 MI criteria includes detection of a rise and/or fall of cardiac troponin (cTn) with at least one value above the 99th percentile including:

- Symptoms of acute myocardial ischemia

- New ischemic ECG changes

What is a distinguishing factor between diagnosing MI and UA?

STEMI/NSTEMI = positive troponin

UA = negative troponin

What is a coronary angiography used for?

Diagnosis of CAD, location and extent

What is a stress test used for?

When MI is "ruled out"

What is an echocardiogram used for?

To estimate LVEF

Predicts mortality and HF risk

What can be detected by an echocardiogram as a result of ischemia?

Ventricular wall motion abnormalities = dyskinesis or akinesis

What can an echocardiogram detect about the left ventricle?

Reduced left ventricular ejection fraction (LVEF)

< 40%

How does ST-segment elevation correlate to risk stratification?

Always high risk

How does acute HF s/s correlate to risk stratification?

Always high risk

What are key indicators that the patient is at high risk of death or recurrent MI?

ST-segment depression, positive troponin, recurrent ST-segment changes or angina despite initial medical therapy, signs of acute HF

What are complications of MI?

Death, arrhythmias, acute and chronic HF/cardiogenic shock, LV free wall rupture, pericarditis, ischemic stroke, bleeding

What are short-term ACS treatment goals?

Early restoration of blood flow to the infarct-related artery to prevent infarct expansion or prevent complete occlusion and MI

Prevent death and other MI complications

Prevent coronary artery reocclusion

Relief of ischemic chest discomfort

Resolution of ST-segment and T-wave changes on ECG

What are long-term treatment goals of ACS?

Control of CV risk factors

Prevention of additional CV events like reinfarction, ischemic stroke, HF, stent thrombosis

Improvement in QoL

What are nonpharmacologic therapies for ACS?

Evaluate in ED = admit to cardiac cath lab, CCU, coronary care step down unit with telemetry

Continuous ECG monitoring

Revascularization = PCI or CABG surgery

Bedrest for first 24 hours

Supplemental oxygen if O2 saturation < 90%

What is the primary method of revascularization for STEMI?

Percutaneous coronary intervention

How is a PCI performed?

Intracoronary stent to site of complete coronary artery occlusion placed via femoral artery catheter

What is the STEMI quality measure for fibrinolytics?

≤ 30 min from hospital arrival ("door-to-needle")

What is the STEMI quality measure for primary PCI in PCI capable hospital?

≤ 90 min from first medical contact until stent placed

What is the STEMI quality measure for primary PCI transfer out?

≤ 120 min from first medical contact until stent placed

Describe a drug eluting stent (DES)

Anti-proliferative agents coated on the stent to decrease restenosis

What are downsides of DES and how can they be avoided?

Possible delayed arterial healing and increased stent thrombosis

Importance of using DAPT/P2Y12 receptor antagonists for a longer duration of time

Describe bare metal stents (BMS)

Improvement in balloon angioplasty by preventing arterial closure

What are downsides of BMS?

Higher risk of repeat revascularization and stent restenosis due to growth of arterial tissue

When is BMS used over a DES?

When issues with maintaining DAPT required for DES arise

Issues with adherence to DAPT, high risk of bleeding with DAPT, surgery is imminent (hold DAPT)

What drugs are used for ACS day one?

SL NTG

Antiplatelets = aspirin, P2Y12 inhibitors

Anticoagulants = UFH and bivalirudin

Supportive care = oxygen, morphine, IV NTG, beta-blockers

When are fibrinolytics used in ACS day one?

Used for STEMI

Describe fibrinolytics in STEMI vs. NSTE ACS

STEMI = reduces mortality compared to placebo

NSTE ACS = AVOID because worsens outcomes

Describe aspirin use in ACS

Reduces mortality, CV mortality, reinfarction, and stroke compared to placebo

Describe P2Y12 inhibitor use in ACS

With aspirin reduces CV death, MI or stroke

Used to reduce PCI stent thrombosis

Describe UFH or bivalirudin use in ACS

UFH reduces mortality compared to no anticoagulation

Bivalirudin for PCI decreases major bleeding compared to UFH

Describe morphine use in ACS

Symptomatic benefit only

May decrease preload/venous return to heart in heart failure

Describe beta-blocker use in ACS

Decreases arrhythmic death, decreases infarct size

Worsens outcomes if used early in shock or acute HF

Describe IV NTG use in ACS

No benefit of oral isosorbide mononitrate versus placebo in MI

Reserve IV NTG for HTN and/or acute HF for symptomatic benefit

No benefit in secondary prevention

Describe CCB use in ACS

No benefit in acute MI or secondary prevention

Worsens HF = avoid/CI in LVEF < 40%

What drug classes have been shown to reduce mortality in ACS?

Fibrinolytics in STEMI, aspirin, P2Y12 inhibitors, UFH, and beta blockers

When should SL NTG be used?

In all patients without contraindications

When should IV NTG be used?

Continued angina despite anticoagulation and antiplatelets

Acute HF symptoms

Uncontrolled HTN (second-line after beta-blockers)

How long should nitrates be continued for in ACS?

Continue approximately 24 hours or until PCI

Describe the effect of nitrates on mortality and preload

Does not affect mortality

Reduces preload

What should be monitored for when taking nitrates?

BP for hypotension

What is a common AE of nitrates?

Headache

What is a contraindication of nitrates?

SBP < 90 mmHg

When is fibrinolytic therapy indicated for in STEMI?

Ischemic chest discomfort at least 20 minutes in duration but ≤ 12 hours since symptom onset

ST-segment elevation of at least 1 mm in height in 2 or more contiguous leads or new or presumed new LBBB

What is the goal door-to-needle time for fibrinolytic therapy in STEMI?

< 30 min

Describe the role of fibrinolysis in STEMI

Secondary to PCI

Used only when primary PCI unavailable or transfer to another institution capable of primary PCI is not possible in a short time frame

Why is PCI preferred in STEMI over thrombolytic therapy?

Thrombolytic therapy is associated with a slight but definite excess risk of ICH that occurs predominantly within the first day of therapy

When should fibrinolysis be avoided in STEMI?

If more than 12 hours since symptom onset

Bleeding risk >>> mortality reduction benefit

What are absolute contraindications to fibrinolysis in STEMI?

Active internal bleeding

Prior history of intracranial hemorrhage

History of ischemic stroke within the past 3 months

What is the initial dose of ASA in ACS?

162-325 mg non-enteric coated chewable aspirin as one dose ASAP

Follow up with baby aspirin dose daily

What is recommended for patients with a true aspirin allergy?

A loading dose with clopidogrel

What is an adverse effect of ASA?

Bleeding

What should be monitored while on ASA?

Signs of bleeding, CBC, platelet count

What P2Y12 inhibitor is preferred in patients with ACS undergoing a PCI?

Ticagrelor or prasugrel compared to clopidogrel

How long should DAPT be used following PCI in ACS?

Default duration is 12 months

Shorter DAPT for high bleeding risk patients (1-3 months) with subsequent transition to P2Y12 monotherapy

What anticoagulation is preferred in patients who undergo PCI?

DOACs preferred over warfarin in combination with an APT to reduce the risk of bleeding

NO ASPIRIN

What are escalation strategies for P2Y12 inhibitors?

From clopidogrel to ticagrelor or prasugrel

What are rationales for P2Y12 inhibitor escalation?

Stent thrombosis, drug interaction, drug intolerance, inadequate antiplatelet effect

What are de-escalation strategies for P2Y12 inhibitors?

From ticagrelor or prasugrel to clopidogrel

What are rationales for P2Y12 inhibitor de-escalation?

Bleeding, need for an oral anticoagulant, insurance copay

What heparin is indicated in patients undergoing PCI?

IV UFH

If a patient undergoing PCI has HIT, what is indicated?

Bivalirudin or argatroban

What are anticoagulation clinical pearls for STEMI?

Start UFH in ED or start Bivalirudin in cath lab suite or switch to bivalirudin from UFH

Continue through PCI procedure and discontinue at end of procedure

What are anticoagulation clinical pearls for NSTE ACS?

Start UFH and continued until PCI or exercise stress test

What pharmacotherapy is used in the ED for STEMI?

SL NTG, aspirin, anticoagulant, fibrinolytic, oral P2Y12 inhibitor, IV NTG

What anticoagulants are used in the ED for STEMI?

UFH started in ED or bivalirudin started in cath lab if transport quick

When are fibrinolytics used in the ED for STEMI?

If no primary PCI available

What oral P2Y12 inhibitor is used in the ED for STEMI?

Ticagrelor

What pharmacotherapy is used in cath lab for primary PCI?

P2Y12 inhibitor if not already given (prasugrel immediately after coronary angiography)

Bivalirudin (if UFH not already given; can switch from UFH to bivalirudin)

What pharmacotherapy is contraindicated in NSTE ACS?

Fibrinolytics = only for STEMI

What pharmacotherapy is used in the ED for NSTE ACS?

SL NTG, aspirin, anticoagulant (UFH), oral P2Y12 inhibitor (no prasugrel)

What is the early invasive strategy for NSTE ACS after risk stratification?

High risk = coronary angiography with PCI if appropriate, usually hospital day 1-2

What is the ischemia-guided strategy for NSTE ACS after risk stratification?

Low risk = d/c anticoagulant hospital day 2, perform stress to evaluate for ischemia

If positive for ischemia, go to coronary angiography and if appropriate, PCI

When should secondary prevention be started post-MI?

Start before hospital discharge and evaluate regimen at 6 weeks post-MI

What are secondary prevention therapies post-MI?

ASA indefinitely

P2Y12 inhibitor

b-blocker within 24 h

High-intensity statin as early as possible

Evaluate for ACEi/ARB and AA

What is the goal LDL for secondary prevention of MI?

< 70 mg/dL

What are benefits to statins, ezetimibe, and PCSK-9 inhibitors in secondary prevention of MI?

Statins = reduce mortality and stroke

ALL = CV mortality

What are benefits to ACEi/ARBs in secondary prevention of MI?

Reduces mortality, CV death, stroke and development of HF

What are benefits to aldosterone antagonists/MRAs in secondary prevention of MI?

Reduces mortality, CV death, HF, hospitalizations for CV causes

What medications are recommended in ACS patients with HF?

Beta-blockers, ACEi, MRAs

When should beta-blockers be initiated?

Within 24 hours

When should beta blockers NOT be initiated?

SBP < 90-100 mmHg or signs of acute HF = may precipitate cardiogenic shock

HR < 60 bpm

S/s of acute HF

How should beta-blockers be monitored?

HR for bradycardia, telemetry/ECG for heart block, BP for hypotension

Chronic = fatigue

What is the goal BP post MI for secondary prevention?

< 130/80 mmHg

What are the agents of choice for HTN post MI secondary prevention?

ACEi/ARBs

Beta-blockers

What do ACEi/ARBs reduce?

Development of HF, mortality, stroke

Who do ACEi/ARBs have more benefits in?

LVEF < 40%

What is a contraindication of ACEi/ARBs?

Potassium > 5.5 mEq/L

How should ACEi/ARBs be monitored?

SCr, potassium

What are the target doses of ACEi that show a mortality reduction in acute MI?

Enalapril 10 mg PO BID

Lisinopril 20 mg PO daily

When should eplerenone or spironolactone be initiated post-MI?

All post-MI patients with EF ≤ 40% and EITHER symptomatic HF at some time during hospital admission OR DM

Typically started after hospital discharge at follow-up clinic apt.

What are benefits to eplerenone and spironolactone when added to ACEi and beta blockers?

Reduces mortality

When are eplerenone and spironolactone contraindicated?

Potassium > 5.0 mEq/L (when added to ACEi/ARB)

SCr ≥ 2.5 mg/dL for men and SCr ≥ 2.0 mg/dL for women and/or CrCl ≤ 30 mL/min

What should eplerenone and spironolactone be monitored for?

SCr, potassium

Spironolactone = gynecomastia

What medications can increase the risk of hyperkalemia when starting eplerenone or spironolactone?

Finerenone, NSAIDs, pentamadine, azole antifungals

Discontinue when possible

When should SGLT2 inhibitors be used post-MI?

Presence of HF

First line in T2DM to reduce MACE

CKD especially with albuminuria when eGFR 20-45 mL/min/m^2 with UACR < 200 mg/g