AHA Addresses Severe Manifestations of Venous Thromboembolism



A recently released scientific statement from the American Heart Association provides guidance for the management of the more severe forms of venous thromboembolism.

The statement focuses on three areas: massive and submassive pulmonary embolism, iliofemoral deep vein thrombosis, and chronic thromboembolic hypertension. "The goal is to provide practical advice to enable the busy clinician to optimize the management of patients with these severe manifestations of [venous thromboembolism]," said the writing committee, cochaired by Dr. Michael R. Jaff and Dr. M. Sean McMurtry (Circulation 2011 Mar. 21 [doi:10.1161/CIR.0b013e318214914f]).

In an interview, Dr. McMurtry noted that because these disease areas have less data to support management strategies than do other areas of cardiovascular medicine, most of the recommendations in the document are class II ("it is reasonable" or "may be considered") with level of evidence B or C (limited populations evaluated). "The authors hope that this document will inspire more research into these conditions," said Dr. McMurtry of the University of Alberta, Edmonton.

Massive and Submassive Pulmonary Embolism

The document begins by defining "massive," "submassive," and "low-risk" pulmonary embolism (PE), and provides data for the various techniques, including clinical scores, echocardiography, computed tomography, elevated troponins/natriuretic peptides, and electrocardiography, that can be used to identify patients at increased risk for adverse short-term outcomes in acute PE.

Beyond initial heparin anticoagulation therapy, the use of fibrinolytic drugs is reasonable for patients with massive acute PE and an acceptable risk of bleeding complications, the statement said. It may also be considered for patients with submassive acute PE judged to have clinical evidence of an adverse prognosis (new hemodynamic instability, worsening respiratory insufficiency, severe right ventricle [RV] dysfunction, or major myocardial necrosis) and a low risk of bleeding complications.

Fibrinolysis is not recommended for patients with low-risk PE, or submassive PE with minor RV dysfunction, minor myocardial necrosis, and no clinical worsening. Fibrinolysis is also not recommended for undifferentiated cardiac arrest, wrote Dr. McMurtry, Dr. Jaff of Harvard Medical School, Boston, and their coauthors.

In addition, recommendations are provided for other areas in which data are sparse and optimal management is unclear, including catheter-based therapies. Transcatheter procedures can be performed as an alternative to thrombolysis when there are contraindications or when emergency surgical thrombectomy is unavailable or contraindicated. Catheter interventions can also be performed when thrombolysis has failed to improve hemodynamics in the acute setting.

Hybrid therapy that includes both catheter-based clot fragmentation and local thrombolysis is an emerging strategy, the committee noted.

Adult patients with any confirmed acute PE who have contraindications to anticoagulation or have active bleeding should receive an inferior vena cava (IVC) filter. Further specific guidance is given for the type of filter and for monitoring.

Iliofemoral Deep Vein Thrombosis

IFDVT refers to complete or partial thrombosis of any part of the iliac vein or the common femoral vein, with or without involvement of other lower-extremity veins or the IVC. Under this heading, the document addresses the use of initial coagulant therapy, long-term anticoagulant therapy, compression therapy, IVC filters, and thromboreductive strategies, including systemic, catheter-directed, percutaneous mechanical, and pharmacomechanical thrombolysis. Surgical venous thrombectomy is also discussed as an alternative method of thrombus removal in IFDVT.

"Reasonable" angiopathy and stenting options for older adolescents and adults include the use of percutaneous transluminal venous angioplasty and stent placement in the iliac vein to treat obstructive lesions after catheter-directed thrombolysis (CDT), pharmacomechanical CDT (PCDT), or surgical venous thrombectomy, and placement of iliac vein stents to reduce postthrombotic symptoms and heal venous ulcers in patients with advanced postthrombotic symptoms and iliac vein obstruction. "For obstructive iliac vein lesions that extend into the common femoral vein, caudal extension of stents into the common femoral vein is reasonable if unavoidable," they wrote. Guidelines regarding subsequent therapeutic anticoagulation are also provided.

The authors noted that "the use of percutaneous transluminal venous angioplasty in children may be reasonable, but this practice has not been well studied and may be associated with a greater risk of vasospasm."

Chronic Thromboembolic Pulmonary Hypertension

The section on CTEPH outlines the incidence, pathophysiology, classification, risk factors, natural history, clinical presentation, diagnostic evaluation, and treatment with pulmonary endarterectomy and medical therapies. The condition is a syndrome of dyspnea, fatigue, and exercise intolerance caused by proximal thromboembolic obstruction and distal remodeling of the pulmonary circulation that leads to elevated pulmonary artery pressure and progressive RV failure, the statement said.

Patients presenting with unexplained dyspnea, exercise intolerance, or clinical evidence of right-sided heart failure, with or without a prior history of symptomatic venous thromboembolism, should be evaluated for CTEPH, and it is reasonable to evaluate patients with an echocardiogram 6 weeks after an acute pulmonary embolism to screen for persistent pulmonary hypertension that may predict the development of CTEPH.


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