Duration of anticoagulation for DVT/PE: Consider risk factors for recurrence, bleeding risk, patient preference
Presenter: Stephan Moll, MD, University of North Carolina, Chapel Hill
Thrombosis Management: What’s New and Different? Presented April 29, 2023.
The duration of anticoagulant treatment in patients with venous thromboembolism (VTE), ie, deep venous thrombosis (DVT)/pulmonary embolism (PE), is predicated on a conglomerate of thrombosis risk factors, bleeding risk factors, and patient preference, said Stephan Moll, MD, University of North Carolina, Chapel Hill.
The risk of VTE is often multifactorial, consisting of weak, moderate, and strong risk factors. “A proximal DVT classically is treated with at least 3 months of anticoagulation whereas the distal DVT is not very symptomatic, and if the risk factor is gone, such as air travel, then we don’t need to treat,” said Dr. Moll. “The main thing for us in clinical practice is, once we’ve defined the clot is to identify the risk factors. I never use the term ‘provoked’ DVT because it could be provoked by mild, moderate, or severe risk factors, and that determines how long we treat.”
Examples of strong risk factors according to the European Society of Cardiology are a previous VTE, myocardial infarction within the previous 3 months, major trauma, hip or knee replacement, hospitalization for heart failure or atrial fibrillation/flutter, lower limb fracture, and spinal cord injury. Some risk factors are transient and others are permanent, which helps to determine the risk of recurrence and therefore also guides duration of treatment.
A patient with DVT who has minimal risk factors is not considered a “clotting nightmare,” he said. Such a patient might be one with a current DVT but no prior thrombosis despite two pregnancies, multiple years on oral contraceptives, and prior colon surgery, for example, as opposed to the patient who clots within 2 weeks of having come off anticoagulation, whom he does call a clotting nightmare, in part to persuade the patient to be compliant with anticoagulation.
Bleeding risk factors include thrombocytopenia due to hypersplenism, coagulopathy from liver cirrhosis with an elevated baseline prothrombin time and partial thromboplastin time, hemorrhoids, esophageal varices, colon cancer with a fungating mass and a previous bleeding episode, and anemia with microcytosis from iron deficiency.
The final consideration in decision-making is patient preference. He said, “I use the warfarin hate factor, [asking the patient] how much on a scale from 0 to 10 do you hate to be on warfarin?” A direct oral anticoagulant (DOAC) is an option in those with a strong dislike for warfarin for reasons of convenience. Bleeding risk is essentially the same with warfarin and a DOAC.
Risk factors for a first clot and the risk for recurrent DVT are considered together when deciding the duration of anticoagulation. “Everybody who has had a DVT or PE or any clot has some risk for recurrence if they come off anticoagulation,” said Dr. Moll. Short-term treatment (3 to 6 months) is adequate for patients with a low risk of recurrence, such as those with major transient risk factors such as hip replacement or colon resection. “We say 3 to 6 months [for short-term anticoagulation] because there’s no clear guidance; often 3 months is sufficient,” he said. “If it was a significant event with residual symptoms, people may go after 6 months, and that’s okay.”
In contrast, a man with two unprovoked prior clots, for example, has a strong risk of recurrence and is a strong candidate for long-term anticoagulation if bleeding risk is acceptable and he tolerates the treatment well. A man with unprovoked DVT/PE has a 30% cumulative VTE recurrence risk at 5 years. Women with unprovoked DVT/PE who stop anticoagulation have a lower risk of recurrence (15% over 5 years) than men with unprovoked DVT/PE who terminate treatment, but the risk is still high enough to make them strong candidates for long-term anticoagulation.
The 5-year cumulative VTE recurrence risk is only 3% in a patient with DVT/PE as a result of a major transient risk factor.
The challenging patients are those with intermediate risk for recurrence, he said. This group is often poorly defined, and a D-dimer test while the patient is on anticoagulation can help to define their risk of recurrence. A negative D-dimer predicts a low risk for recurrence to guide a decision to stop anticoagulation. Dr. Moll repeats a D-dimer 4 weeks after stopping anticoagulation to further refine risk. A positive D-dimer in a patient on anticoagulation indicates the need to continue anticoagulation.
References
Konstantinides SV, Meyer G. The 2019 ESC guidelines on the diagnosis and management of acute pulmonary embolism. Eur Heart J 2019; 40(42):3453–3455. doi: 10.1093/eurheartj/ehz726
Otel TL, Neumann I, Ageno W, et al. American Society of Hematology 2020 guidelines for management of venous thromboembolism: treatment of deep vein thrombosis and pulmonary embolism. Blood Adv 2020; 4(19):4693–4738. doi: 10.1182/bloodadvances.2020001830
Kearon C, Akl EA. Duration of anticoagulant therapy for deep vein thrombosis and pulmonary embolism. Blood 2014; 123(12):1794–1801. doi: 10.1182/blood-2013-12-512681
Douketis J, Tosette A, Marcucci M, et al. Risk of recurrence after venous thromboembolism in men and women: patient level meta-analysis. BMJ 2011; 342:d813. doi: 10.1136/bmj.d813
Disclosures
Stephan Moll, MD, has no relationships with entities whose primary business is producing, marketing, selling, re-selling, or distributing healthcare products used by or on patients.