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ESSENTIALS OF DIAGNOSIS
Otherwise unexplained dyspnea, tachypnea, or chest pain.
Clinical, electrocardiogram, radiographic or echocardiographic evidence of acute right ventricular failure.
Positive computed tomographic pulmonary angiography scan.
High-probability ventilation-perfusion lung scan or high-probability perfusion lung scan with a normal chest radiograph.
Positive venous ultrasound of the legs with a convincing clinical history and suggestive lung scan.
Positive invasive pulmonary angiogram.
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GENERAL CONSIDERATIONS
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The term “venous thromboembolism” (VTE) encompasses both pulmonary embolism (PE) and deep venous thrombosis (DVT) and is a common cause of hospitalizations. Pulmonary embolism leads to or contributes to at least 100,000 deaths per year in the United States. With the widespread availability of computed tomographic pulmonary angiography (CT-PA) in mainstream clinical practice, a larger proportion of PE cases are now being diagnosed. The estimated incidence of PE has approximately doubled since the introduction of CT-PA in routine clinical practice, from 62.1 to 112.3 cases per 100,000 individuals in the United States. At the same time, the mortality of PE has decreased 33% from about 12% to 8%. Much of this effect can be attributed to increased recognition of low to moderate risk PEs. High-risk and intermediate high-risk PEs still carry significant morbidity and mortality. Risk stratification is now a central feature of society guidelines: attempting to minimize cost by encouraging outpatient treatment of low-risk VTE while promoting diagnostic vigilance in high- and intermediate-risk VTE. Improvements in noninvasive diagnostics now facilitate early recognition and intervention of high-risk PE, but realizing the benefits of these advancements is contingent on physicians being savvy with the interpretation of CT-PA and echocardiographic features of right ventricular (RV) failure. Improved noninvasive diagnostics also help identify and monitor disabling long-term complications of VTE like chronic thromboembolic pulmonary hypertension (CTEPH) and chronic venous insufficiency. Direct oral anticoagulants (DOACs) have created opportunities for improving outcomes and reducing costs via improved safety profiles and ease of administration, but DOACs have shortcomings in certain disease states of which providers must be aware. Lastly, VTE events raise important considerations like whether an occult malignancy is present, future risk of VTE, and whether risk extends to family members via inherited traits.
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“Primary” PE occurs in the absence of surgery or trauma. Patients with this condition often have an underlying hypercoagulable state, although a specific thrombophilic condition may not be identified. A common scenario is a clinically silent tendency toward thrombosis, which is precipitated by a stressor such as prolonged immobilization, oral contraceptives, pregnancy, or hormone replacement therapy. Recently, there has been an increased appreciation of the risks of VTE among patients with medical illnesses, including cancer (which itself may be associated with a hypercoagulable state), congestive heart failure, chronic obstructive pulmonary disease, and infectious diseases like COVID-19.
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The prevalence of “secondary” PE is high among patients undergoing certain types of surgery, especially orthopedic surgery of the hip and knee, gynecologic cancer ...