Immediate parenteral anticoagulation is required for intermediate-high-risk and high-risk pulmonary embolism, with advanced reperfusion therapies indicated for high-risk patients and those who deteriorate.
This review outlines an approach to risk stratification and acute management of intermediate- and high-risk pulmonary embolism, including the use of advanced therapies such as systemic thrombolysis and catheter-based interventions.
Pulmonary embolism (PE) is the third leading cause of cardio vascular death in Canada, with an annual incidence of 1 in 1000; it affects more than 46 000 people in Canada and leads to about 1 death every 8 hours. 1,2Between 9% and 11% of patients diag nosed with PE die within 30 days, with PErelated death occurring in 2% and bleedingrelated death occurring in 0.5%. 344]5 Pulmonary embolism occurs when a venous thrombus becomes lodged in lung arteries, usually causing impairment in oxygenation, circula tion, and heart function. 6,7As many as 1% of patients who survive PE subsequently develop chronic thromboembolic pulmonary hypertension, 8 and almost 50% experience chronic exertional breathlessness secondary to chronic thromboembolic disease or postPE syndrome. 9As many as half of patients report reduced quality of life, 10 with depression, anxiety, and posttraumatic stress disorder all prevalent among PE survivors. 11,12ecause patients with PE present with a wide range of disease severity, risk stratification at the time of diagnosis is essential to establish a prognosis and guide therapy. 13,14The requirement for timesensitive adjuvant interventions once anticoagulation has been initiated increases with disease severity.Selection of appropriate patients for advanced therapy (systemic thrombo lysis or catheterbased therapy) is often complex, with compet ing risks and benefits, and lack of highlevel randomized evi dence to guide decisionmaking.We discuss the treatment of PE following initial diagnosis con firmed with contrastenhanced computed tomography (CT).Fol lowing a confirmed diagnosis of PE, immediate anticoagulation therapy is indicated, in concert with risk stratification to guide fur ther management options (Figure 1, Table 1).Herein, we focus on the acute management of intermediate-highrisk (American Heart Association AHA categories C3, D1, and D2) and highrisk PE (AHA cat egories E1 and E2).We outline an approach to risk stratification based on clinical features and guidelines, and discuss the latest evidence for advanced therapies, including systemic thrombolysis and catheter based interventions in select patients (Box 1). Why is risk stratification important for PE?Intermediate-highrisk and highrisk PE are lifethreatening emergencies.The main determinant of morbidity and death from acute PE is right ventricular (RV) dysfunction, 15 whereby obstruc tion of the pulmonary arteries leads to abrupt increases in RV afterload, causing a vicious cycle of elevated RV pressure, pro gressive RV dilation, RV ischemia, RV systolic dysfunction, impaired left ventricular (LV) filling, and low cardiac output. 16ight ventricular dysfunction confers an elevated risk of hemo dynamic deterioration, adverse events and, in its most severe form, culminates in cardiovascular collapse and death. 171819 How are intermediate-high-risk and high-risk PE defined and classified?According to the 2019 European Society of Cardiology (ESC) guideline 13 and category E in the AHA 2026 guideline, 20 highrisk PE, previously referred to as "massive," is defined by the pres ence of hemodynamic instability, characterized by a systolic blood pressure less than 90 mm Hg, the use of vasopressors, a persistent drop in systolic blood pressure of more than 40 mm Hg from baseline, or cardiac arrest.Intermediaterisk PE, previously referred to as "submassive" (AHA categories C2 to D2), is defined Review
Mendelson et al. (Sun,) conducted a review in Intermediate- and high-risk pulmonary embolism. Anticoagulation and advanced reperfusion therapies was evaluated. Immediate parenteral anticoagulation is required for intermediate-high-risk and high-risk pulmonary embolism, with advanced reperfusion therapies indicated for high-risk patients and those who deteriorate.