The survival rate of a pulmonary embolism (PE) is a variable outcome dependent on prompt diagnosis and the initial severity of the condition. PE is a blockage in one of the pulmonary arteries in the lungs, usually caused by a blood clot (embolus) that has traveled from the deep veins of the legs (deep vein thrombosis or DVT). This obstruction prevents blood from reaching the lungs for oxygenation and puts strain on the right side of the heart. A patient’s prognosis is determined by the clot’s size, the resulting stress on the heart, and the patient’s underlying health.
Baseline Survival Statistics
The difference between a diagnosed and an undiagnosed pulmonary embolism is significant. When left undiagnosed and untreated, acute PE is associated with a mortality rate as high as 30%. Up to 10% of patients with acute PE die suddenly, often before reaching medical care.
Once PE is diagnosed and treated promptly, the mortality rate drops significantly, stabilizing around 8%. This difference highlights the life-saving impact of rapid medical intervention.
Factors That Determine Prognosis
The most significant factor determining prognosis is the severity of the PE, classified based on the patient’s hemodynamic status. High-risk or “massive” PE is defined by hemodynamic instability, such as persistent low blood pressure or shock. This type carries the highest mortality risk, with 90-day mortality rates approaching 58%.
In contrast, low-risk PE occurs when the patient is hemodynamically stable, meaning blood pressure and heart function are maintained despite the clot burden. These cases have a favorable prognosis, with a 90-day mortality rate less than 2%. Intermediate-risk PE falls between these extremes; the patient is stable but shows signs of right heart strain or injury, associated with a 90-day mortality rate of about 15%.
A patient’s underlying health status (comorbidities) also modifies the risk profile. Advanced age, pre-existing heart failure, and active cancer increase the risk of death substantially, even independently of clot size. These factors are incorporated into scoring systems to predict a patient’s short-term outcome.
The Critical Role of Early Diagnosis and Treatment
Rapid medical response and immediate treatment improve survival rates across all severity levels of PE. Standard treatment involves anticoagulation (“blood thinners”), which prevents existing clots from growing and stops new clots from forming. This therapy stabilizes the patient and allows the body time to naturally break down the obstruction.
For patients with high-risk PE experiencing shock or severe low blood pressure, aggressive reperfusion therapies are necessary to dissolve or remove the blockage. Systemic thrombolysis (“clot-busting” drugs) is the preferred first-line treatment in these situations. However, this intervention carries a significant risk of major bleeding, including intracranial hemorrhage.
If thrombolysis is contraindicated or the patient remains unstable, mechanical interventions are considered. These include catheter-directed thrombolysis (CDT), which delivers the drug directly into the clot, or surgical pulmonary embolectomy, which involves physical clot removal. The decision on aggressive therapy involves a multidisciplinary team to quickly weigh risks and benefits.
Recovery and Long-Term Outcomes
After surviving the acute PE event, recovery focuses on preventing recurrence and managing long-term complications. Patients receive anticoagulation for several months to reduce the likelihood of a second event. While most survivors fully recover, up to 50% may experience lingering symptoms known as Post-PE Syndrome (PPES).
PPES includes persistent shortness of breath, fatigue, and functional impairment. The most serious long-term complication is Chronic Thromboembolic Pulmonary Hypertension (CTEPH), which develops when blood clots scar and fail to fully resolve. This rare condition occurs in 0.6% to 4.8% of survivors.
CTEPH causes high blood pressure in the lungs, forcing the right side of the heart to work harder, leading to heart failure. Untreated, CTEPH has a poor prognosis. Specialized treatments, such as pulmonary thromboendarterectomy (PTE) surgery, can significantly improve long-term survival for eligible patients. Ongoing monitoring is required to detect these complications early.