Death from massive PE is one of the most common causes of unexpected death, being second only to coronary artery disease as a cause of sudden unexpected natural death at any age. Most clinicians do not appreciate the extent of the problem, because the diagnosis is unsuspected until autopsy in approximately 80% of cases. Although PE often is fatal, prompt diagnosis and treatment can reduce the mortality dramatically.
Patients who survive an acute PE are at high risk for recurrent PE and for the development of pulmonary hypertension and chronic pulmonary heart disease, attendant mortality and morbidity.
Although the frequency of PE increases with age, age is not an independent risk factor. Rather, it is the accumulation of other risk factors, such as underlying illness and decreased mobility, that causes the appearance of PE with increased frequency in older patients. In the UK, an average of one passenger per month dies of a pulmonary embolism caused by deep vein thrombosis soon after landing at London's Heathrow airport.