Antithrombotic Therapy: A Study Guide for VTE and Acute Coronary Syndromes

740 Exam 2 Study Guide VTE (DVT and PE) Part 1 (Van): Venous Thromboembolism (VTE): Clot formation within the venous circulation as DVT or PE (fatal) Upper Extremity DVT: Proximal (axillary veins), catheter-associated Lower Extremity DVT: Proximal (popliteal or more proximal veins), Distal (call-veins) 3 Types of PE Massive: cause hemodynamic compromise (sustained hypotension-lightheadedness) Sub-massive: causing RV dysfunction/dilation, indicated by biomarkers (Troponins) Non-massive (low risk): no RV dysfunction or hemodynamic compromise Recurrent VTE: Highest probability in 180 days after initial VTE Virchow's Triad: 3 Factors Leading to Thrombosis: Endothelial injury, abnormal blood flow, hypercoagulability (Inherited thrombophilia - prothrombin gene mutation) Risk Factors: Age, VTE history, blood stasis (immobility, surgery, paralysis), vascular (endothelial) injury Acquired factors: • Malignancy (secrete clotting factors) • Pregnancy/Postpartum (fetus press on pelvis, hard for blood to reach legs) • Antiphospholipid antibodies (autoimmune disease) • COVID-19 • Drug-therapy (estrogen, cancer therapy, HIT) Long-distance Travelers (>6 hr flights) Smoking (current smoker + estrogen BC = greater risk) Complications of VTE: Post-thrombotic syndrome: long-term effect caused by damage in the venous valves Chronic thromboembolic pulmonary hypertension (CTPH): o From 1+ PE episodes o Increase Vascular resistance and pressure VTE Laboratory Tests: D-dimer: less than 500 ng/mL RULES OUT VTE diagnosis (cannot rule-in) Diagnostic DVT Tests (Rule-In): Compression Ultrasound: most common DVT diagnosis test (non-invassive) Venography: Gold standard (invasive/expensive) anaphylaxis & nephrotoxicity 740 Exam 2 Study Guide Diagnostic PE Tests (Rule-In): Computerized tomography pulmonary angiography (CTPA): most commonly used Pulmonary Angiography: Gold standard (invasive/expensive) mortality risk VTE Risk Assessment: Non-surgical (hospitalized) patients - Padua Prediction Score: o High risk VTE > 4; Low risk <4 Surgical Patients - Caprini Score: 0 Estimates VTE risk after surgery High Bleeding Risk Assessment Model: 1 of these 3 (or 2+ of 8 remaining factors, list provided) Active GI Ulcer, Bleeding in 3 mo before admission, or Platelet count <50K/cm 3 Non-Pharm Prophylaxis: Mechanical Thromboprophylaxis: 0 Intermittent Pneumatic Compression (IPC) devices: wear 18+hr/day o Compression stockings Benefit: no increased bleeding risk, can be used in pt's with contraindications to pharmacologic therapies Risk: discomfort, skin breakdown, & ulcerations Inferior Vena Cava (IVC) Filters (head scratcher): • Provide short-term protection against PE in very-high-risk pt's 0 Block embolism via filter, minimally invasive o Unproven mortality benefit, increase long-term complications (filter migration) o For pt's at highest VTE risk when other strategies can't be used o Removed when VTE risk passes or anti-coag is no longer contraindicated Pharm Prophylaxis Options: Hospitalized NON-critically III: • Low VTE/bleeding risk: no prophylaxis • Increased VTE Risk but not high bleeding risk: LMWH, low-dose UFH (BID or TID), or Arixtra Límit duration, only till pt is mobile or discharged For immobilized pt's, routine thromboprophylaxis is not recommended o Increased VTE Risk & High-Bleeding Risk: IPC or stockings Consider prophylaxis pharm options when bleeding risk decreases, if VTE risk continues Hospitalized Critically III: • Not High Risk for Bleeding: LMWH or low-dose UFH • High Bleed Risk: IPC or compression stockings Consider prophylaxis pharm options when bleeding risk decreases 740 Exam 2 Study Guide Road Map: o angina EKG (check for STEMI) if no, check biomarkers (NSTEMI) if none, UA STEMI Risk Assessment: 0 All STEMI's = HIGH RISK, immediate reperfusion needed UA or NSTEMI Risk Assessment: • TIMI score (thrombolysis in myocardial infarction) High-risk: 5-7, Med.: 3-4, Low: 0-2 Determines urgency of catheterization Acute ACS Management: • STEMI Goals: IMMEDIATE REPERFUSION Primary PCI (stent) w/in 90 min (if transfer needed, give thrombolytic within 30 min and PCI within 120 min) • NSTEMI GOAL: prevent total vessel occlusion Active Supportive Care: THROMBINS2 (MONA no longer used) o Thienopyridine (P2Y12 inhibitor) - Plavix o Heparin o Renin-Angio-Aldos System (ACE/ARB) • Oxygen • Morphine o B-blocker o Intervention (PCI) • Nitroglycerine o Statin/Salicylate (ASA) Aspirin: • Loading dose: 325 mg CHEWED AND SWALLOWED immediately NTG Dosing: 0.4mg SL q5min x3 prn chest pain Tachyphylaxis (tolerance) more common with NTG drip Caution: SBP<90; PDE5-I taken win 24-48 h Oxygen: 2-4 L/min if 02 sat. <90% Morphine: o Dosing: 2-4mg IV q5-15min prn refractory pain Pain worsens ischemia Monitor: respiratory rate 740 Exam 2 Study Guide 0 Alternative: Fentanyl 25-100 mcg q5-15min prn pain (less side effects) Acute Treatments - Antiplatelets: (AT LEAST 2) o ASA (Aspirin) P2Y12 Inhibitors. Clopidogrel (Plavix) Irreversible inhibitor Prodrug-2 step activation via CYP2C19 oxidation Loading Dose: 300mg po 1x, then 75mg po QD High interpatient variability o Test CYP2C19 genotype & consider an alternative Pasugrel (Effient) Irreversible inhibitor (Prodrug-1 step activation) Dosing: 60mg po 1x, then 10 mg po qd (5mg if pt <60kg) BBW: active bleeding, prior TIA/CVA Contraindicated: >75 y.o., <60kg Ticagrelor (Brillinta) Reversible inhibitor Dosing: 180 mg PO 1X then 90mg PO BID Contraindications: ASA dose >100mg (BBW), hepatic dysfunction Cangrelor (Kengreal) Reversible binding IV: 30 mcg/kg IV, then 4 mcg/kg/min IV inf (min. 2 hr) 1-2 hrs for platelet recovery b/c it's reversible • GP IIb/illa Inhibitors (IV infusions)- infusions)-NOT for low risk NSTE-ACS tx Tirofiban (Aggrastat) Renal dosing CrCl<30mL/min Contraindicated: CVA (stroke) in past 30 days Eptifibatide (Integrilin) o Renal dosing CrCI<50mL/min o Contraindicated: CVA (stroke) in past 30 days & hemodialysis pt's Selecting Antiplatelet Therapy: UA or NSTEMI: (DO NOT USE FIBRINOLYTICS!-they are only for STEMI) ALL get at least 2 antiplatelet therapies ASA + Clopidogrel or Ticagrelor** preferred High Risk pt's: triple therapy ASA+P2Y12 inhibitor + GP IIb/Illa inhibitor 740 Exam 2 Study Guide STEMI: ALL get dual antiplatelet therapy Fibrinolytic: ASA + Clopidogrel PCI: ASA+P2Y12 inhibitor • Some PCI pt's may receive triple therapy. Acute Treatments - Anticoagulants: (PICK 1) • Unfractionated Heparin (UFH) STEMI w/Fibrinolytics or NSTEMI or UA 60 units/kg IV 1X (max 4,000 units), then 12 units/kg/hr (max 1,000 units/hr) Continue x48h or until PCI performed Up to 8 days or discharge • Enoxaparin (Lovenox) STEMI Dosing: Age Cro Bolus Dose Maintenance Deve Max Dose first a duses sommin omg amg 500 75mg 2万 a jommin Noire mg 50 daily None (200mg) 2n None amglig 50 daily None samg?) o x8 days or until discharge If CrCl<30: 1mg/kg SQ QD If CrCl30: <75 y.o. 1mg/kg SQ BID 75 y.o. 0.75mg/kg SQ BID UA/NSTEMI Dosing: No bolus, 1mg/kg SQ BID (only QD for CrCl<30) • Until resolution of ischemia (22 days) o Fondaparinux (Arixtra) STEMI with Fibrinolytic Therapy: 2.5mg IV1x then 2.5mg SQQD o x8 days or until discharge or revascularization Contraindicated: CrCl <30 • Bivalirudin (Angiomax)-not for low risk NSTE-ACS D/C 0-4 hr after PCI PCIpt not already on Bivalirudin 0.75mg/kg IV bolus, then 1.75mg/kg/hr 740 Exam 2 Study Guide Caution with GPIIb/Illa inhibitors 1 Selecting an Anticoagulant: • All pt's should receive an anti-coag plus antiplatelet therapy Acute Management: Fibrinolytics (STEMI only!) o Fibrin-specific: Alteplase (Activase) or tPA 15mg IV over 1-2 min 0.75mg/kg IV (max 50mg) over 30 min 0.5 mg/kg IV (max 35mg) over 1 hr Total: Do Not Exceed 100mg *Must be administered with UFH or LMWH Reteplase (Retavase) or rPA Teneteplase (TNKase) or TNK-PA Fibrinolytic Contraindications • Active bleeding, known intracranial neoplasm, any prior intracranial hemorrhage, Ischemic stroke within previous 3 mo., known cerebral vascular malformation, aortic dissection, closed head or facial trauma within previous 3 months, intracranial or intraspinal surgery within 2 months, and severe uncontrolled hypertension Anti-ischemic treatments: o NTG, B-blockers, non-DHP CCBS Post-ACS: A-Antiplatelet/Anti-coag o ASA continue indefinitely • B-Blood pressure (BB, ACE/ARB, NTG) Beta-blockers: (unless C/l) decreases myocardial 02 demand ACE/ARB: all post-MI pt's w/in 24h unless C/I SL NTG: all pt's unless C/I • C-Cholesterol & cigarettes (smoking cessation) Statins: Pleiotropic effects, no Simvastatin 80 mg • D-Diet & DM management o E-Exercise • Specials POPS: Aldosterone Antagonists: Pt's w/ LVeF <40% & DM or symptoms of HF Aldactone Heparin-Induced Thrombocytopenia (HIT) (Louie): 5-6 Q's Heparin: any type, at any dose, via any route (IV or SQ) Thrombocytopenia: abnormal low platelet count (platelets help blood clot)