3 Acute Myocardial Infraction Part II: Reperfusion Therapies for UA, NSTEMI, and STEMI
4 Professor Department of Emergency Medicine, University of Illinois at Chicago Chicago, IL (email@example.com) Edward P. Sloan, MD, MPH, FACEP
5 Attending Physician Emergency Medicine University of Illinois Hospital Our Lady of the Resurrection Medical Center
6 Global Objectives Learn more about AMI and ACS Increase awareness of Rx options Enhance our ED management Improve patient care & outcomes Maximize staff & patient satisfaction Be prepared for the EM board exam
37 AMI/ACS Rx: Beta-blockade AMI/ACS Rx: Beta-blockade Consider in all AMI and ACS pts Continued, recurrent ischemic pain Tachyarrhythmias: rapid AFib, Flutter May even be useful in patients with relative contraindications Metoprolol 5mg IV q5mx3 Within 12 hours of presentation
38 AMI/ACS Rx: Beta-blockade AMI/ACS Rx: Beta-blockade Contraindications Moderate to severe CHF COPD/asthma Bradycardia Hypotension 2 nd or 3 rd degree A-V blocks
39 AMI/ACS Rx: Beta-blockade AMI/ACS Rx: Beta-blockade Not consistently achieved in AMI Why do clinicians defer this Rx? May be optimal with HTN, tachycardia With HR < 80, normal BP, less use Not mandated in the ED, prior to PCI
40 AMI/ACS Rx: Ca ++ Channel Rate control in atrial fib, flutter If unable to provide beta blockade Not viewed in same way a use of metoprolol in AMI
41 AMI/ACS Rx: Digitalis Rapid load in rapid atrial fibrillation Provided before beta blocker use Not used for its inotropic effects
42 AMI/ACS Rx: Lidocaine AMI/ACS Rx: Lidocaine Limited use New, symptomatic VT Malignant dysrhythmias, VF 1-1.5 mg/kg, 2-4 mg/min drip Caution in ventricular escape rhythm Can cause asystole No real prophylactic use
43 AMI/ACS Rx: Magnesium AMI/ACS Rx: Magnesium Documented Mg deficit with diuretics Prolonged QT, torsade de pointes VT 1-2 gram bolus over 5 minutes Empiric therapy in refractory VF?
49 AMI/ACS Rx: Dopamine AMI/ACS Rx: Dopamine Dopamine useful in ED Enhanced vital organ flow Supports nitrates with labile BP Increases HR, SVR, cardiac O 2 use Increased inotropy Ischemia, dysrhythmias can occur
50 AMI/ACS Rx: Dobutamine AMI/ACS Rx: Dobutamine Dobutamine can also be used in ED Pulmonary edema, LV dysfunction No endogenous norepi release Less myocardial O 2 use increase Improved inotropy Improved coronary artery flow Can be used with dopamine
51 AMI/ACS Rx: Norepinephrine AMI/ACS Rx: Norepinephrine Used in refractory hypotension No response to other pressors Increased myocardial O 2 use Improved inotropy, but no increase in cardiac output as SVR is increased Ectopy, dysrhythmias can occur
53 AMI/ACS Rx: Diuretics AMI/ACS Rx: Diuretics Furosemide: NaCl clearance Used in pulmonary edema & LV dysfunction Volume, Starling effects More optimal LV filling, stroke volume, and cardiac output
54 AMI/ACS Rx: ACE Inhibitors AMI/ACS Rx: ACE Inhibitors Reduces LV dilatation and dysfunction, improves remodeling Slows development of CHF AMI/ACS patients, especially critically ill anterior wall MI patients with pulmonary edema show greatest benefit Captopril, enalapril, or lisinopril Early use may reduce mortality
55 AMI/ACS Rx: ACE Inhibitors AMI/ACS Rx: ACE Inhibitors Not mandated to be ED Rx Contraindications Hypotension Bilateral renal artery stenosis Renal insufficiency/failure
56 AMI/ACS Rx: Clot Therapies AMI/ACS Rx: Clot Therapies What are the indications for heparin, IIb/IIIa, and thrombolytic therapy?
57 AMI/ACS Rx: Heparin (LMW) AMI/ACS Rx: Heparin (LMW) What are the indications for heparin and LMW heparin in AMI/ACS patients? How does LMW heparin work differently than un-fractionated heparin?
58 AMI/ACS Rx: Heparin (LMW) AMI/ACS Rx: Heparin (LMW) Prevents late thrombus formation Maintains patent coronary artery Prevents mural thrombus from forming in anterior wall MI Prevents cerebral emboli with AMI Doesn’t Rx already formed thrombi Platelet Rx: White clot, ACS, NSTEMI Thrombolytic Rx: Red clot, STEMI
59 AMI/ACS Rx: Heparin (LMW) AMI/ACS Rx: Heparin (LMW) Thrombin inhibition Prevents clot propagation, formation High embolism risk pts identified: Large or ant MI, Afib, previous embolus, known LV thrombus Complication reduction: Reinfarction reduced by 30% Mortality reduced by 21%
60 AMI/ACS Rx: Heparin (LMW) AMI/ACS Rx: Heparin (LMW) Indicated in patients with PCI or surgical revascularization Also used in pts who get tPA and those with ACS, NSTEMI
61 AMI/ACS Rx: Heparin AMI/ACS Rx: Heparin Over 1300u/hr associated with bleeding complications Attempt to achieve a PTT that is 1.5-2.0 times normal (60-85 seconds)
62 AMI/ACS Rx: Heparin AMI/ACS Rx: Heparin Bolus: 60 units/kg Infusion: 12 U/kg per hour Max recommended dose 4000 units bolus 1000 units per hour infusion
63 AMI/ACS Rx: LMW Heparin AMI/ACS Rx: LMW Heparin Similar indications to heparin 1 mg/kg SQ BID Prior suggestion that heparin preferred in highest risk pts Some prefer heparin prior to PCI No demonstrated difference between heparin and LMW in these patients
64 AMI/ACS Rx: IIb/IIIa Inhibitors AMI/ACS Rx: IIb/IIIa Inhibitors What are the indications for IIb/IIIa inhibitors in AMI/ACS patients? How do these drugs work?
65 AMI/ACS Rx: IIb/IIIa Inhibitors AMI/ACS Rx: IIb/IIIa Inhibitors Abciximab (ReoPro): long acting Ab Eptifibatide (Integrillin): peptide Tirofiban (Aggrastat): peptide Used in ACS, NSTEMI patients, especially those who undergo PCI High risk patients (positive troponin) Requires 48-72 hrs of infusion to demonstrate benefits
66 AMI/ACS Rx: IIb/IIIa Inhibitors AMI/ACS Rx: IIb/IIIa Inhibitors Useful in treatment of pts with refractory unstable angina Treats white clot: ACS, NSTEMI Few head to head studies that compare IIb/IIIa inhibitors Rate of ICH lower than with fibrinolysis
67 AMI/ACS Rx: IIb/IIIa Inhibitors AMI/ACS Rx: IIb/IIIa Inhibitors 50,000 receptors per platelet Final common pathway Platelets bind with fibrinogen Forms hemostatic plug (white clot) IIb/IIIa glycoprotein prevents this binding and formation of white clot
69 AMI/ACS Rx: IIb/IIIa Inhibitors AMI/ACS Rx: IIb/IIIa Inhibitors Inhibit 80% of receptors, then there is no platelet aggregation Prevents ongoing platelet deposition No effect on thrombin generation No effect on coagulation, inflammation Combo therapy with thrombin drugs Use with heparin is indicated
70 White Clot: ACS, NSTEMI Platelets, Fibrin, Red Cells Platelets, Fibrin, Red Cells
71 AMI/ACS Rx: IIb/IIIa Inhibitors AMI/ACS Rx: IIb/IIIa Inhibitors Beneficial effects of platelet inhibition Decreased re-occlusion after thrombolysis and/or PCI Decreased re-infarction risk because of better coronary artery healing Minimizes extent of occlusion as a result of acute plaque disruption
72 AMI/ACS Rx: IIb/IIIa Inhibitors AMI/ACS Rx: IIb/IIIa Inhibitors Clinical use in ED is indicated in ACS Actual use is somewhat limited by availability of PCI for most critically ill ACS, NSTEMI patients Although use should begin in ED, many cardiologists begin infusion following PCI Still important prior to transfer for PCI
73 AMI/ACS Rx: Thrombolytics AMI/ACS Rx: Thrombolytics What are the indications for thrombolytic therapy in AMI/ACS patients? How do thrombolytics work?
74 Red Thrombus in STEMI Thrombin, fibrin, clotting factors
75 AMI/ACS Rx: Thrombolytics AMI/ACS Rx: Thrombolytics Time is muscle Restoration of TIMI-3 flow Myocardial salvage Reduced ventricular dysfunction Reduced ectopy Sudden death less likley
76 AMI/ACS Rx: Thrombolytics AMI/ACS Rx: Thrombolytics Indications Classic history EKG with > 1mm ST in 2 limb leads or > 2mm ST in > 2 precordial leads New LBBB
77 AMI/ACS Rx: Thrombolytics AMI/ACS Rx: Thrombolytics No contraindications No cardiogenic shock (??) Presentation within 12 hours of symptom onset
78 AMI/ACS Rx: Thrombolytics AMI/ACS Rx: Thrombolytics Maximal benefit when given within first 2 hours of infarct Greater mortality benefit in patients with anterior wall AMI as opposed to those with inferior wall AMI
84 AMI/ACS Rx: Thrombolytics AMI/ACS Rx: Thrombolytics Absolute contraindications Any active bleeding Recent GI bleed (within 10 days) Hemorrhagic CVA at any time Non-hemorrhagic CVA in last 6 months
85 AMI/ACS Rx: Thrombolytics AMI/ACS Rx: Thrombolytics Absolute contraindications Aortic dissection Pericarditis Childbirth within 10 days HTN (SBP >200 or DBP>120)
86 AMI/ACS Rx: Thrombolytics AMI/ACS Rx: Thrombolytics Absolute contraindications Intracranial/spinal mass lesion, aneurysm, AV malformation Surgery within 2 months Serious head trauma in last month Bleeding disorder Pregnancy
87 AMI/ACS Rx: Thrombolytics AMI/ACS Rx: Thrombolytics Relative Contraindications Traumatic CPR PUD Current anticoagulant use Hx of HTN with DBP > 100
90 AMI/ACS Rx: Cardiac Pacing AMI/ACS Rx: Cardiac Pacing What are the indications for cardiac pacing in AMI/ACS patients?
91 AMI/ACS Rx: Cardiac Pacing AMI/ACS Rx: Cardiac Pacing For large anterior STEMIs Not as an Rx for vagal reaction To Rx symptomatic bradycardia Overdrive suppression (+/-)
92 AMI/ACS Rx: Cardiac Pacing Transcutaneous Cardiac Pacing Sinus brady, low BP, no Rx effect Mobitz type II second degree block Third degree block Bifascicular block LBBB RBBB or LBBB & first degree AV block Less so for stable bradycardia, RBBB
93 AMI/ACS Rx: Cardiac Pacing Transvenous Cardiac Pacing Asystole Sinus brady, low BP, no Rx effect Mobitz type II second degree block Third degree block Bifascicular block RBBB & first degree AV block (+/-) Overdrive suppression for VT (+/-) 3 sec sinus pauses, no Rx effect (+/-)
94 AMI/ACS Rx: Cardiac Pacing Cardiac Pacing Approach Establish rhythm disturbance Determine that rate, rhythm are effecting adequate perfusion Attempt to Rx BP Attempt to improve rate with atropine Attempt transcutaneous pacing Place sheath for transvenous pacer Insert transvenous pacer as needed
95 AMI/ACS Mechanical Interventions Mechanical Ventilation Intubation, mechanical ventilation Decreased work of breathing Increases BP (hopefully) Decreases myocardial O 2 use Increases O2 delivery (CHF) Critical in cardiogenic shock
96 AMI/ACS Mechanical Interventions Intraaortic Balloon Pump What are the indications for intraaortic balloon pump support in AMI/ACS patients? How does the intraaortic balloon pump work?
98 AMI/ACS Mechanical Interventions Intraaortic Balloon Pump Refractory cardiogenic shock As a stabilizing measure prior to PCI Acute mitral regurgitation, VSD (STEMI mechanical complications) Intractable ventricular dysrhythmias Refractory post-MI ischemia, as bridge Unstable pts when LV is “at risk” (+/-)
99 AMI/ACS Mechanical Interventions Percutaneous Coronary Interventions What is PCI? What are the PCI indications? What is the goal of PCI? Over what time period should revascularization occur?
100 AMI/ACS Rx: Revascularization AMI/ACS Rx: Revascularization Over what time period should revascularization occur? ACEP and AHA/ACC guidelines 120 minutes door to balloon time If not, consider tPA use in ED
101 AMI/ACS Mechanical Interventions Percutaneous Coronary Interventions PCI optimal for single lesion, grafts May be able to treat multiple lesions May require multiple procedures Extensive small vessel disease precludes effective PCI Rx Multiple occluded vessels: CABG
102 AMI/ACS Mechanical Interventions Percutaneous Coronary Interventions PCI is the industry standard Door to balloon time can be > 120 min When PCI is imminent: Front loaded tPA not often utilized IIb/IIIa inhibitors not often utilized Need to optimize ED process
103 AMI/ACS Rx: EMS Triage AMI/ACS Rx: EMS Triage Is there evidence to support directed triage to “cardiac” centers?
104 AMI/ACS Rx: EMS Triage AMI/ACS Rx: EMS Triage Is there evidence to support directed triage to “cardiac” centers? No. It is unclear that door to balloon time is significantly decreased, nor is patient outcome worsened if a transfer agreement is in place Caveat: cardiogenic shock patients probably would benefit from direct triage for immediate PCI
105 AMI/ACS Rx: Pre-hospital Rx AMI/ACS Rx: Pre-hospital Rx What out-of-hospital therapies have been demonstrated to improve outcome in AMI?
106 AMI/ACS Rx: Pre-hospital Rx AMI/ACS Rx: Pre-hospital Rx 911 activation Early defibrillation, first responders 12 lead EKG, thrombolysis (+/-)
107 AMI/ACS: Specific Issues Elderly and females associated with more atypical presentations Pts with symptoms of AMI/ACS after PCI should be assumed to have abrupt vessel closure
108 AMI/ACS: Hospital Admission Pts at high risk for CAD, AMI, or death admit to ICU ED observation units and non-ICU monitored beds are safe for pts with normal ECGs and low to moderate risk Low risk patients: 2 hour rule out and outpatient stress testing
109 History Case #1 58 year old male Chest pain, sub-sternal, severe Onset less than one hour prior Nausea, diaphoresis No known cardiac history Smoker, ?cholesterol
110 Px Case #1 98.8 100/60 110 24 Gen: Screaming in pain, diaphoretic Chest: BS equal CV: Reg rhythm without
121 Diagnosis Case #2 Inferior wall MI Likely R coronary artery occlusion
122 Treatment Case #2 IV NTG ASA, Oxygen Morphine Heparin Rapid transfer for PTCA
123 Conclusions AMI/ACS Rx in the E.D. Common problem ED staff has an important role Many therapies are available Chance to make a difference Good guidelines exist Interested consultants
124 Conclusions AMI/ACS: Relevant Questions Is there an acute plaque rupture? Is this ACS (white clot) req platelet Rx? Is this STEMI (red clot) req TT, PCI? What Rx must be provided in the ED? How can revascularization best be achieved given the ED processes?