Abstract
Chronic thromboembolic pulmonary hypertension (CTPH) is believed to result from single or recurrent pulmonary thromboemboli arising from sites of venous thrombosis. The occurrence of CTPH after a diagnosis of acute pulmonary embolism has been considered to be rare. A recent article in the Journal estimated that CTPH occurs in 0.1 to 0.5 percent of cases of acute, nonfatal pulmonary thromboemboli.1 The natural history of pulmonary thromboemboli includes total resolution or resolution with minimal residua and restoration of normal pulmonary hemodynamics within 30 days in more than 90 percent of patients. Repeated catheterization after acute pulmonary embolism has led to the . . .