Fosinopril is an angiotensin converting enzyme (ACE) inhibitor used for the treatment of hypertension and some types of chronic heart failure. Fosinopril is the only phosphonate-containing ACE inhibitor marketed, by Bristol-Myers Squibb under the trade name Monopril. Fosinopril is a cascading pro-drug. The special niche for the medication that differentiates it from the other members of the ACE Inhibitor drug class is that was specifically developed for the use for patients with renal impairment. This was through manipulation of the metabolism and excretion, and is seen that fifty percent of the drug is hepatobiliary cleared, which can compensate for diminished renal clearance. The remaining fifty percent is excreted in urine. It does not need dose adjustment. It was patented in 1980 and approved for medical use in 1991. Medical uses
In congestive heart failure, the ability of the heart to pump enough blood to satisfy the physiological needs of the body is reduced. This condition has a variety of causes, including damaged heart valves, myocardial infarction, hypertension, vitamin B1 deficiency, and genetic mutations. When subsequent blood flow to the kidneys is reduced, the kidneys respond by increasing the secretion of renin from the juxtaglomerular apparatus. Renin converts the inactive angiotensinogen into angiotensin I, which is converted to angiotensin II (AII) by angiotensin converting enzyme (ACE). AII can have negative effects on the cardiovascular system after events such as heart failure and myocardial infarction. AII causes arterial vasoconstriction and hypertension, resulting in an increase in afterload, increasing the resistance against which the heart works.
Pulmonary (or pulmonic) insufficiency (or incompetence, or regurgitation) is a condition in which the pulmonary valve is incompetent and allows backflow from the pulmonary artery to the right ventricle of the heart during diastole. While a small amount of backflow may occur ordinarily, it is usually only shown on an echocardiogram and is harmless. More pronounced regurgitation that is noticed through a routine physical examination is a medical sign of disease and warrants further investigation. If it is secondary to pulmonary hypertension it is referred to as a Graham Steell murmur. Signs and symptoms
Because pulmonic regurgitation is the result of other factors in the body, any noticeable symptoms are ultimately caused by an underlying medical condition rather than the regurgitation itself. However, more severe regurgitation may contribute to right ventricular enlargement by dilation, and in later stages, right heart failure. A diastolic decrescendo murmur can sometimes be identified,( heard best) over the left lower sternal border. Causes
Among the causes of pulmonary insufficiency are:

Pathophysiology
The pathophysiology is due to diastolic pressure variations between the pulmonary artery and right ventricle, differences are often very small, but increase regurgitation. An elevation in pulmonary insufficiency due to elevated intrathoracic pressure is relevant in ventilated patients (having acute restrictive right ventricular physiology). The reasons for changes in stiffness of the right ventricles walls are  not well understood, but such stiffness is thought to increase with hypertrophy of the ventricle.