Acute pulmonary embolism

Acute Pulmonary Embolism David Maldonado MD Mayo Clinic Rochester, MN, USA Agenda • Pathophysiology • Risk Factors and Epidemiology • Diagnosis • Treatment • Prophylaxis and Prevention • Proposed Algorithms Acute Pulmonary Embolism • • • • Part of a spectrum of venous thrombotic disease Severity from asymptomatic to sudden death Often occurs without prior warning Signs and symptoms are nonspecific and therefore diagnosis often delayed or missed • Treatments are effective in reducing risk of death • Hospital-based prevention can reduce frequency Tapson VF VF N Engl J Med 2008 Mar 6;358(10):103752 Incidence • DVT/PE per 1,000 patient visits • PE found in 10% of autopsies Silverstein MD et al, Arch Intern Med 1998 Mar 23;158(6):585-93 • 83% of patients who died of PE also had LE DVT on autopsy • Only 20% had LE symptoms • Only 3% had undergone evaluation for DVT/PE prior to death Sandler DA, Martin JF J R Soc Med 1989 Apr;82(4):203-5 Risk Factors • ACQUIRED: • Older age • Postoperative (joint replacement, hip fracture, • • • • • cancer surgeries) Trauma or spinal cord injury Malignancy Pregnancy, Oral contraceptives, Estrogen Prior venous thrombosis Obesity • HEREDITARY: • Protein C or S deficiency, Protein C resistance • Antithrombin III deficiency • (Factor V Leiden or Prothrombin mutation) Age Silverstein MD et al, Arch Intern Med 1998 Mar 23;158(6):585-93 Thrombotic Risk in Asia Is it Different? • Obesity less common • According to United Nations, only 10% older than 65, vs 20-30% in Europe and U.S • Asian diet may reduce risk • Factor V Leiden and Prothrombin mutation absent Ho CH, et al Am J Hematol 2000; 63: 74-8 • Joint replacement surgery less common SMART Study Group • Analysis of published studies • Malaysia, Thailand, Hong Kong, Korea, Singapore, Taiwan, and Japan • Postoperative thrombosis • General surgery 13% • Hip replacement 16% • Knee replacement 50% • Pulmonary embolus 2% • Total • Autopsy studies 6% Leizorovicz A et al., Int J Angiol 2004; 13: 101-8 SMART Study • Large (2420 patients), prospective, multinational study • Bangladesh, India, Indonesia, Malaysia, Pakistan, Philippines, Singapore, South Korea, Taiwan, and Thailand • Orthopedic surgery patients treated without DVT/PE prophylaxis • Rate of symptomatic DVT/PE 1.2-2.3% • Risk factors: History of venous thrombosis, CHF, varicose veins Leizorovicz A et al J Thromb Haemost 2005 Jan;3(1):28-34 • MRI – can detect PE but speed, availability, and cost currently prohibitive • Echocardiography – findings of right heart dysfunction suggestive of acute PE • Lower Extremity Doppler Ultrasound – consider in patients unable to tolerate other diagnostic imaging • Pulmonary Angiography – Major complication rate 1-5%, Mortality 0.5-1.0% Laboratory Studies • Arterial Blood Gas – • Neither sensitive nor specific • Does not assist in diagnosis • D-dimer (ELISA) - 96-98% sensitivity • When negative in a patient with low-medium • suspicion, imaging not required In a patient of high PE suspicion, D-dimer should not be used • Troponin – • Elevated levels often found in those who go on to develop complications • Brain Natriuretic Peptide – • Compliments D-dimer and Troponin EKG Treatment • Anticoagulation • Thrombolytics • Embolectomy • Prophylaxis Parenteral Anticoagulation to Treat Acute PE • • • • • • Low Molecular Weight Heparin Unfractionated Heparin Pentasaccharide Fondaparinux Decrease clot burden without thrombolysis Improve survival Should be started prior to imaging if suspicion is high • Lepirudin or Argatroban if HIT develops Anticoagulation after hospitalization • While in hospital on parenteral anticoagulation, warfarin should be initiated with a target INR 2.0 to 3.0 • Duration depends on scenario • Transient risk factor 3-6 months 6-12 months • Idiopathic • Malignancy (LMWH) indefinite 6-12 months • Protein C/S, AT3 • or more episodes indefinite Buller HR et al., Chest2004;126:401S428S.) Thrombolysis • Tissue plasminogen activator (t-PA), streptokinase, urokinase • Accepted for PE with cardiogenic shock • Data insufficient in submassive PE • Elevated troponin and echocardiographic RV failure may warrant thrombolysis • Contraindications: recent trauma or major surgery, bleeding, pregnancy, intracranial/spinal/ocular disease 03:30 Embolectomy • Catheter-based Mechanical Embolectomy • Surgical Embolectomy • Not supported by evidence for most PE’s • Mortality 20-70% for surgical embolectomy • Only in “selected highly compromised patients who are unable to receive thrombolytic therapy or whose critical status does not allow sufficient time to infuse thrombolytic Buller HR therapy” et al., Chest2004;126:401S-428S.) Prevention/Prophylaxis • All hospitalized patient should be considered and need assessed • Medical prophylaxis superior to mechanical • LMWH superior to UFH in knee or hip replacement, trauma, and spinal cord injury • LMWH equivalent to UFH in medical inpatients Potential Diagnostic Algorithm • • • • • • • • Low/moderate suspicion D-dimer D-dimer normal No treatment D-dimer abnormal CT Angio CT Angio normal No treatment CT Angio reveals PE Treatment CT Angio non-diagnostic Doppler U/S Doppler U/S normal No treatment Doppler U/S abnormal Treatment • (No treatment still need DVT/PE prophylaxis as inpatients) High Suspicion Algorithm • • • • • • • Consider treatment prior to testing with CT Angio CT Angio normal or nondiagnostic Doppler U/S CT Angio reveals PE Treatment Doppler U/S normal V/Q scan Doppler U/S reveals DVT Treat as PE V/Q scan low probability No treatment V/Q scan positive or indeterminate Treat Treatment Algorithm • Anticoagulation contraindicated • All others IVC Filter LMWH or heparin (Echo troponin, BNP) • • • Echo, troponin, BNP abnormal Consider lytics Clinical shock Thrombolytics Thrombolytics contraindicated Embolectomy [...]... Ultrasound • Standard Pulmonary Angiography Chest X-Ray • Cannot diagnose or exclude PE • Suggestive but infrequent signs • Westermark’s Sign • Hampton’s Hump • Non-specific Signs • Atelectasis • Pleural Effusion • Infiltrate • Elevated Hemidiaphragm Westermark’s Sign Hampton’s Hump Ventilation-Perfusion (V/Q) Scan • Interpretable best in the absence of other underlying cardiopulmonary disease • Normal... lobar, and segmental pulmonary arteries readily seen • In patients suspected of PE who have negative CT arteriography, the risk of DVT/PE Swensen SJ et al., Mayo Clin Proc in 3 months 0.5% 2002; 77: 130-8 • False positive studies very unusual • MRI – can detect PE but speed, availability, and cost currently prohibitive • Echocardiography – findings of right heart dysfunction suggestive of acute PE • Lower... currently prohibitive • Echocardiography – findings of right heart dysfunction suggestive of acute PE • Lower Extremity Doppler Ultrasound – consider in patients unable to tolerate other diagnostic imaging • Pulmonary Angiography – Major complication rate 1-5%, Mortality 0.5-1.0% Laboratory Studies • Arterial Blood Gas – • Neither sensitive nor specific • Does not assist in diagnosis • D-dimer (ELISA) - 96-98%... to develop complications • Brain Natriuretic Peptide – • Compliments D-dimer and Troponin EKG Treatment • Anticoagulation • Thrombolytics • Embolectomy • Prophylaxis Parenteral Anticoagulation to Treat Acute PE • • • • • • Low Molecular Weight Heparin Unfractionated Heparin Pentasaccharide Fondaparinux Decrease clot burden without thrombolysis Improve survival Should be started prior to imaging if suspicion