What Is the Initial Therapy for Acute PE with Right Heart Strain but No Hypotension?

May 29, 2026 · Pouyan Golshani, MD, Interventional Radiologist

A 64-year-old woman, three weeks post-total knee arthroplasty, presents to the emergency department with acute-onset dyspnea and pleuritic chest pain. Her blood pressure is stable at 118/76 mmHg, but she is tachycardic to 110 bpm. A computed tomography angiography (CTA) confirms extensive bilateral pulmonary emboli. The key findings are concerning: the right ventricle to left ventricle (RV/LV) ratio is 1.2, a bedside echocardiogram shows right ventricular hypokinesis, and her troponin level is elevated. She is normotensive, but all signs point to significant right heart strain. This clinical picture places her in the intermediate-risk, or submassive, pulmonary embolism category, a critical decision point for initial management. This article details the American College of Radiology (ACR) Appropriateness Criteria workflow for this specific, high-stakes scenario, where both Anticoagulation and Catheter-directed therapy are rated as Usually Appropriate.

Who Fits This Clinical Scenario for Intermediate-Risk Pulmonary Embolism?

This guidance applies to a specific subset of adult patients with a confirmed diagnosis of acute pulmonary embolism (PE). The key is that while the patient is currently hemodynamically stable (normotensive), there is clear objective evidence of significant physiologic stress on the heart.

Inclusion criteria for this workflow:

Diagnosis: Confirmed acute bilateral pulmonary emboli.
Imaging Evidence: RV/LV ratio greater than 0.9 on CTA.
Echocardiographic Evidence: Signs of right heart strain (e.g., RV dilation, hypokinesis, septal bowing).
Biomarker Evidence: Elevated cardiac troponin level, indicating myocardial injury.
Hemodynamics: Systolic blood pressure remains above 90 mmHg.

This combination of findings defines intermediate-risk (or submassive) PE. The patient is not in shock but is at a heightened risk of decompensation.

Exclusion criteria (patients who fit a different workflow):

Hypotensive Patients: An adult with extensive PE and sustained hypotension (systolic BP < 90 mmHg for over 15 minutes) is classified as having a massive PE. This is a distinct, higher-acuity scenario requiring a different, more aggressive management algorithm.
Low-Risk PE: A patient with a PE but a normal RV/LV ratio (< 0.9), normal troponin, and no signs of right heart strain on an echocardiogram is considered low-risk. Their management typically involves anticoagulation alone without the consideration of advanced therapies.
Absolute Contraindications to Anticoagulation: Patients with active, life-threatening bleeding or other absolute contraindications to anticoagulation require a separate management pathway, often involving an IVC filter.

What Is the Primary Clinical Concern in This Scenario?

In this scenario, the diagnosis of pulmonary embolism is already established. The clinical workup is no longer about identifying the cause of symptoms but about risk-stratifying the patient to prevent the most feared complication: hemodynamic collapse. The “differential” is one of outcomes, not diagnoses.

The primary concern is impending cardiovascular collapse. The combination of RV dilation, RV dysfunction on echo, and myocardial injury (elevated troponin) signals that the right ventricle is failing to pump effectively against the high pressure caused by the pulmonary artery clot burden. While the patient is currently normotensive, this is a tenuous stability. A small increase in clot burden or a decrease in cardiac contractility could precipitate a rapid decline into obstructive shock, cardiac arrest, and death. The entire management strategy is focused on unloading the right ventricle to avert this outcome.

A secondary, longer-term concern is the development of Chronic Thromboembolic Pulmonary Hypertension (CTEPH). In a fraction of patients, the acute clot fails to resolve completely, leading to chronic scarring and obstruction of the pulmonary arteries. This results in persistent pulmonary hypertension and progressive right heart failure. While the immediate goal is survival, the choice of initial therapy may influence the degree of clot resolution and the potential for long-term complications like CTEPH. The decision-making process must balance the immediate risk of death against the risks of more aggressive therapies.

Why Are Anticoagulation and Catheter-Directed Therapy ‘Usually Appropriate’?

For the normotensive patient with intermediate-risk PE, the ACR panel designates two initial therapies as Usually Appropriate: Anticoagulation and Catheter-directed therapy. This reflects a critical clinical decision point where the choice depends on the patient’s trajectory, bleeding risk, and institutional capabilities.

Anticoagulation is the foundational treatment for nearly all patients with PE. It works by preventing the propagation of existing thrombus and the formation of new clots, allowing the body’s own fibrinolytic system to begin breaking down the emboli. For many patients in this category, anticoagulation alone is sufficient to stabilize them and promote gradual recovery. It is the universal standard of care and the starting point for management.

Catheter-directed therapy (CDT) is also rated Usually Appropriate because it offers a method to rapidly decrease the clot burden and, consequently, the strain on the right ventricle. This is a crucial advantage in a patient who shows signs of impending failure. CDT involves placing a catheter directly into the pulmonary arteries to administer low-dose thrombolytics (e.g., tPA) or to perform mechanical or aspiration thrombectomy. By actively removing or dissolving the clot, CDT can lead to a more rapid improvement in RV function and hemodynamics than anticoagulation alone. This makes it a vital option for patients who appear to be worsening or who have a high-risk feature profile.

The decision between anticoagulation alone versus anticoagulation plus early CDT is often made by a multidisciplinary Pulmonary Embolism Response Team (PERT).

Why Other Therapies Are Rated Lower

Systemic Thrombolysis: This is rated Usually not appropriate. While effective at dissolving clots, full-dose systemic thrombolysis carries a significantly higher risk of major bleeding, including intracranial hemorrhage, compared to CDT. In a patient who is not hypotensive, the risks of systemic lytics are generally felt to outweigh the benefits, especially when more targeted options like CDT are available.
Surgical Embolectomy: Rated as May be appropriate (Disagreement), this option is typically reserved for patients with very large, central clots who have a contraindication to thrombolysis or in whom catheter-based therapies have failed or are unavailable. It is a major open-heart surgery with its own substantial risks and is not a first-line therapy for a stable patient.

What’s Next After Initial Therapy? Downstream Workflow

The patient’s clinical course in the hours and days following the initial therapeutic choice dictates the subsequent steps. Close monitoring in an intensive care unit (ICU) or step-down unit is essential.

If Anticoagulation Alone is Chosen: The patient must be monitored closely for any signs of clinical deterioration. If the patient develops hypotension, worsening tachycardia, increased oxygen requirement, or worsening RV function on repeat echo, this represents treatment failure. At this point, the patient’s status has escalated, and they should be immediately evaluated for rescue therapy, which may include catheter-directed therapy or, in severe cases, systemic thrombolysis or ECMO.
If Catheter-Directed Therapy is Performed: Following the procedure, the patient will be continued on therapeutic anticoagulation. The primary goal is to see objective improvement in vital signs, oxygenation, and RV function on a follow-up echocardiogram. If the patient stabilizes and improves, they can be transitioned from an intravenous to an oral anticoagulant and eventually discharged.
If the Patient Decompensates into Shock: If, despite initial measures, the patient develops sustained hypotension, they have transitioned into the massive PE category. This is a medical emergency. The workflow now aligns with the ACR variant for Adult. Extensive acute bilateral central pulmonary emboli. Sustained hypotension for more than 15 minutes. This often involves immediate consideration of systemic thrombolysis or extracorporeal membrane oxygenation (ECMO) as a bridge to definitive therapy.

Pitfalls to Avoid (and When to Get Help)

Managing intermediate-risk PE requires vigilance to avoid common pitfalls that can lead to poor outcomes.

Complacency with “Stable” Vitals: A normal blood pressure can be falsely reassuring. The presence of RV strain and elevated troponins are ominous signs that must be taken seriously. Do not underestimate the risk of sudden decompensation.
Delaying a Multidisciplinary Discussion: This is the archetypal scenario for a PERT consultation. The decision to escalate beyond anticoagulation is complex and benefits from input from pulmonology, cardiology, interventional radiology, and cardiothoracic surgery.
Ignoring Relative Contraindications: Carefully assess the patient’s bleeding risk before considering any form of thrombolysis, even low-dose catheter-directed lytics. A recent surgery, history of gastrointestinal bleeding, or underlying coagulopathy must be weighed against the potential benefit.

Escalation: If the patient’s respiratory status worsens, they develop new hypotension, or their mental status changes, this is a sign of impending collapse. This requires immediate escalation to the ICU and an urgent PERT activation or code-level response.

Frequently Asked Questions

Why is this patient considered ‘intermediate-risk’ if their blood pressure is normal?

The ‘intermediate-risk’ or ‘submassive’ classification is based on the presence of right ventricular (RV) dysfunction, not just blood pressure. The elevated RV/LV ratio, signs of strain on the echocardiogram, and elevated troponin all indicate the heart is struggling under the load of the clot. While the blood pressure is currently normal, this is a fragile state with a high risk of sudden hemodynamic decompensation.

What is a PERT, and why is it important in this scenario?

A PERT, or Pulmonary Embolism Response Team, is a multidisciplinary team of specialists (often including pulmonology, cardiology, interventional radiology, and cardiac surgery) who can rapidly convene to make shared decisions for complex PE cases. For intermediate-risk PE, a PERT is crucial for weighing the risks and benefits of anticoagulation alone versus advanced therapies like catheter-directed therapy, tailored to the individual patient and institutional resources.

If both anticoagulation and catheter-directed therapy are ‘Usually Appropriate,’ how do I choose?

The choice is individualized. Anticoagulation alone may be sufficient for a patient who is clinically stable and showing no signs of worsening. Catheter-directed therapy is often favored for younger patients with low bleeding risk, those with a very high clot burden, or those showing subtle signs of worsening (e.g., increasing oxygen needs, rising heart rate). This decision is best made in consultation with a PERT or local specialists.

Does the location of the emboli (e.g., saddle vs. peripheral) change this recommendation?

While the clot burden and location contribute to the overall physiologic impact, the ACR criteria for this specific scenario are driven by the objective evidence of right heart strain (RV/LV ratio, echo findings, biomarkers), not the clot’s location itself. A patient with a saddle embolism but no RV strain would fall into a lower-risk category, whereas a patient with multiple bilateral segmental emboli causing significant strain fits this intermediate-risk profile.

What is the role of an IVC filter in this specific patient?

An IVC filter is generally not a first-line therapy for this patient. IVC filters are typically reserved for patients with acute PE who have an absolute contraindication to anticoagulation (e.g., active life-threatening hemorrhage) or in cases of recurrent PE despite adequate anticoagulation. For this patient, the primary goal is to treat the existing clot and RV strain with anticoagulation and/or catheter-based therapies.

Reviewed by Pouyan Golshani, MD, Interventional Radiologist — May 30, 2026