Erythropoietic response to cyanosis will promote erythrocytosis, and with phlebotomy, microcytosis will increase hyperviscosity and its likely complications such as cerebrovascular and thromboembolic events. Once the patient develops irreversible pulmonary vasculopathy and heart failure, death usually occurs with a mean survival of only 2-3 years 2. Some patients with pulmonary hypertension secondary to severe chronic mitral stenosis may show regression post operatively, but in general, they die prematurely if they develop frank right ventricular failure. Different modalities of therapy have changed the course of the disease significantly. Most of the reports implicate right ventricular failure to be the number one cause of death followed by the arrhythmogenic sudden death.
Pneumonia is the next but far less cause of death.
The main reasons for the clinical neglect of primary pulmonary hypertension have been its dismal prognosis when untreated and, until today, the absence of effective treatments. The best surgical procedure would be a treatment modality that alleviates the pulmonary hypertension to improve the cardiac output and reduce the chances of arrhythmogenic irritable right ventricle and in this day in age be cost effective. Theoretically, this should improve survival. There are several observations suggesting that atrial shunting in primary pulmonary hypertension seems to give better survival. It has been shown that patient with congenital heart disease, pulmonary hypertension and Eisenmenger syndrome live longer.