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.
Whilst PE can arise from deep vein thrombosis anywhere in the body, thrombus in the popliteal segment of the femoral vein (the segment behind the knee) causes PE in more than 60% of cases. One important autopsy study showed that more than 35% of patients who died from PE had isolated calf vein thrombosis. Fatal PE more often results from thrombus that originates in the axillary or subclavian veins (deep veins of the arm or shoulder) or in veins of the pelvis. Thrombus that forms around indwelling central venous catheters is a common cause of fatal PE.
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.
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.