This rate is roughly 10% after 30 days, 15% after three months and up to 20% after one year. Pulmonary embolisms alone (when resulting in hospitalizations) have a case fatality rate of about 5% to 10% so VTE can play a large factor in the severity of the embolisms.When looking at all cases, the rate of fatal pulmonary emboli has declined from 6% to 2% over the last 25 years in the United States. In Europe, an average of approximately 40,000 deaths per year with pulmonary embolism as the primary cause were reported between 2013 and 2015, a conservative estimate because of potential underdiagnosis. Prognosis
Less than 5 to 10% of symptomatic PEs are fatal within the first hour of symptoms.There are several markers used for risk stratification and these are also independent predictors of adverse outcomes. These include hypotension, cardiogenic shock, syncope, evidence of right heart dysfunction, and elevated cardiac enzymes. Some ECG changes including S1Q3T3 also correlate with a worse short-term prognosis. There have been other patient-related factors such as COPD and chronic heart failure thought to also play a role in prognosis.Prognosis depends on the amount of lung that is affected and on the co-existence of other medical conditions; chronic embolisation to the lung can lead to pulmonary hypertension. After a massive PE, the embolus must be resolved somehow if the patient is to survive. In thrombotic PE, the blood clot may be broken down by fibrinolysis, or it may be organized and recanalized so that a new channel forms through the clot.
CTPA is non-inferior to VQ scanning, and identifies more emboli (without necessarily improving the outcome) compared to VQ scanning. Ventilation/perfusion scan
A ventilation/perfusion scan (or V/Q scan or lung scintigraphy) shows that some areas of the lung are being ventilated but not perfused with blood (due to obstruction by a clot). This type of examination is as accurate as multislice CT, but is less used, due to the greater availability of CT technology. It is particularly useful in people who have an allergy to iodinated contrast, impaired kidney function, or are pregnant (due to its lower radiation exposure as compared to CT). The test can be performed with planar two-dimensional imaging, or single photon emission computed tomography (SPECT) which enables three-dimensional imaging. Hybrid devices combining SPECT and CT (SPECT/CT) further enable anatomic characterization of any abnormality. Low probability diagnostic tests/non-diagnostic tests
Tests that are frequently done that are not sensitive for PE, but can be diagnostic. Chest X-rays are often done on people with shortness of breath to help rule-out other causes, such as congestive heart failure and rib fracture. Chest X-rays in PE are rarely normal, but usually lack signs that suggest the diagnosis of PE (for example, Westermark sign, Hamptons hump). Ultrasonography of the legs, also known as leg doppler, in search of deep venous thrombosis (DVT). The presence of DVT, as shown on ultrasonography of the legs, is in itself enough to warrant anticoagulation, without requiring the V/Q or spiral CT scans (because of the strong association between DVT and PE).