Sildenafil—A Possible Treatment for Acute Pulmonary Hypertension During Cardiac Surgery

Primary pulmonary hypertension has an annual incidence of 1 to 2 cases per million people in the general population and an onset in the third to fourth decades of life (1). It is a progressive disease that affects women twice as frequently as men; the mean survival time from diagnosis is 2.5 years (2). Patients with chronic congestive heart failure may develop secondary pulmonary hypertension, and this may become a limiting factor for acceptance into a cardiac transplantation program. The new cardiac graft will have a normal-sized right ventricle that may fail when exposed to the increased workload of a preexisting elevated pulmonary vascular resistance (PVR). It is vitally important to prevent acute elevations in PVR intraoperatively in patients undergoing cardiac transplantation with marginally acceptable levels of pulmonary hypertension. The mechanisms to treat an acute rise in pulmonary artery pressures in these circumstances are limited.