You are consulted for recommendations regarding a deep vein thrombosis in a patient who is status post aortic valve replacement with a bioprosthetic valve 4 days prior. Earlier on the day of consult he complained of pain and was diagnosed with a partially occlusive left femoral vein thrombosis. His postoperative course has been otherwise uncomplicated. On examination, the patient is tender around the surgical site. There is moderate pitting edema in the legs bilaterally. He has palpable pulses in all extremities.
What do you recommend?
Begin a weight-based unfractionated heparin infusion. Although LMWH may be appropriate as the initial anticoagulant of choice for the treatment of an acute DVT in the ambulatory as well as hospitalized patient, it does not require a bolus. In the setting of the postoperative state where rapid reversal of anticoagulation may be required, unfractionated heparin is favored. An inferior vena cava filter would be an appropriate recommendation if anticoagulation could not be administered at therapeutic levels. Thrombolytic therapy is contraindicated in the setting of recent open heart surgery. Use of a DTI is not indicated for routine anticoagulation.
Reference:
Buller HR, Agnelli G, Hull RD, et al. Antithrombotic therapy for venous thromboembolic disease: the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy. Chest. 2004;126:401S– 428S.
A patient with a history of heparin-induced thrombocytopenia (HIT) 8 years ago presents to your office for preoperative evaluation for bioprosthetic aortic valve replacement and coronary artery bypass grafting. He requires anticoagulation while on cardiopulmonary bypass pump during surgery. A recent ELISA (enzyme-linked immunosorbent assay) antiplatelet factor-4 antibody test is negative (<0.400 optical density). He has had no subsequent heparin exposures over the last 8 years.
What is the most appropriate anticoagulation regimen you should recommend for this patient?
Administration of IV unfractionated heparin intraoperatively with subsequent daily monitoring of platelet counts. The nature of immune response to heparin is anamnestic; this means a second exposure in the absence of positive antibodies is not associated with the development of a clinical hyperacute immune response. Perioperatively, heparin products should be avoided in patients with a history of HIT even with undetectable antiplatelet antibodies prior to cardiac surgery or vascular surgery. Nevertheless, heparin is favored over DTIs in cardiac and vascular surgery because of its reversibility and relative ease of use. Acute HIT is unlikely to occur even in patients who have a remote history of HIT as long as there has been no heparin exposure within the previous 100 days. This recommendation is based on expert opinion (level 1C) and not on randomized controlled trials.
Warkentin TE, Greinacher A. Review heparin-induced thrombocytopenia: recognition, treatment, and prevention: the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy. Chest. 2004;126;311S–317S.
A patient comes to your office 1 month after a hospital stay for gastric bypass surgery. She was diagnosed with a mesenteric vein thrombosis postoperatively. She denies a prior history of venous thromboembolism (VTE). She and her husband have questions about the duration of anticoagulant therapy. They bring copies of laboratory results showing she was checked for a hypercoagulable condition. One laboratory test indicates she is heterozygous for a mutation of the methylenetetrahydrofolate reductase (MTHFR) enzyme. All other laboratory tests are within normal range. She asks you how these results impact duration and intensity of anticoagulation.
The most accurate reply is:
Given the clinical circumstances the laboratory finding is of doubtful clinical significance and you advise she should be anticoagulated with a vitamin K antagonist for 3 months with a target INR of 2.0 to 3.0. While the site of thrombosis is somewhat out of the ordinary, it was in the setting of abdominal surgery and was her first episode; therefore, a routine course of 3 months of anticoagulation with a vitamin K antagonist and an INR target of 2.0 to 3.0 is appropriate. All first-episode venous thrombotic events are not treated the same. Patients with malignancy-related thrombosis, idiopathic events, and those with certain thrombophilic conditions such as the antiphospholipid antibody syndrome require a longer duration of therapy relative to patients with transient risk factors for VTE. The MTHFR genetic mutation in the absence of hyperhomocysteinemia is not associated with increased risk of recurrence after discontinuation of anticoagulant therapy and has not been shown to increase thrombogenicity requiring a higher than usual INR target.
Bates SM, Greer IA, Hirsh J, et al. See use of antithrombotic agents during pregnancy: the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy, Section 5.0. Chest. 2004;126:627S– 644S.
A 34-year-old woman with a history of deep vein thrombosis who is chronically anticoagulated with warfarin discovers she is pregnant. Her due date is 34 weeks from now. Currently, she is on warfarin and has an INR of 2.2. She presents to the clinic for recommendations regarding her anticoagulation management.
Which of the following is true regarding venous thromboembolic disease, anticoagulation therapy, and pregnancy?
Fatal pulmonary embolism is a leading cause of maternal mortality in the Western world. Thromboembolism is clearly the leading direct cause of maternal mortality according to the Seventh Report of the Confidential Enquiries into Maternal Deaths in the United Kingdom. The May-Thurner syndrome involves compression of the left iliac vein by the right iliac artery. The greatest teratogenicity of warfarin is seen during weeks 6 through 12. Use of LMWH in pregnant women who have prosthetic heart valves is highly controversial and certainly not the standard of care.
Young JR, Olin JW, Bartholomew JR, eds. Peripheral Vascular Diseases, 2nd ed. St. Louis, MO: Mosby; 1996:614–617.
A 65-year-old man presents to the clinic with complaints of episodic burning pain involving the soles of his feet and toes. He reports symptoms are most severe when the weather becomes hot and generally occurs when he is outside in the heat. His feet and toes turn red and feel hot to touch during episodes. When he returns to an air-conditioned area, symptoms begin to dissipate or some episodes may take hours for complete resolution. Elevating his legs relieves symptoms as does walking barefoot on cold tile floors. His past medical history includes hypertension, well controlled with atenolol, and he takes once daily low-dose aspirin for primary prevention.
Physical Examination:
Which of the following is the most likely diagnosis?
Erythromelalgia. The name of this condition is based on three Greek words: erythro meaning red, melos meaning extremity, and algos meaning pain. It is uncommon, affecting about 1 in 40,000. It may be primary or secondary. Primary erythromelalgia is usually bilateral, not associated with gangrene, and patients have normal pulses. Secondary erythromelalgia is often unilateral, can be associated with gangrene, and patients have variable pulses. Secondary erythromelalgia can be associated with medications including bromocriptine, nifedipine, nicardipine, and verapamil. It may also herald the onset of a myeloproliferative disease such as polycythemia vera or essential thrombocythemia.
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