The purpose of this study is to evaluate the effects of Coenzyme Q-10, an antioxidant, in the treatment of pulmonary hypertension.

Abnormalities in the blood vessels in the lung are the hallmark of pulmonary hypertension. Links between increased free radical production, mitochondrial dysfunction and pulmonary hypertension have been studied but are poorly understood. The mitochondria of cells is the location where cellular energy is created and free radicals are atoms or groups of atoms with an odd (unpaired) number of electrons and can be formed when oxygen interacts with certain molecules. Once formed these reactive radicals can start a chain reaction, like dominoes. Their chief danger comes from the damage they can do when they react with important cellular components. Cells may function poorly or die if this occurs. The body produces free radicals in the normal course of energy production and in pulmonary hypertension, free radical production is found to be increased. To prevent free radical damage the body has a defense system of antioxidants. Coenzyme Q-10 is an antioxidant and it helps to protect cells from damage caused by the body's own free radicals. By providing oral supplementation of coenzyme Q-10, free radical levels will be decreased and cellular functioning in the pulmonary blood vessels may improve and even return to near normal functioning.

The purpose of this study is to evaluate the effects of coenzyme Q-10, an antioxidant, in the treatment of pulmonary hypertension. We will assess coenzyme Q-10 supplementation in the treatment of pulmonary hypertension by clinical measurements and blood levels of certain cellular components. We would like to assess the effects of coenzyme Q-10 on the pulmonary vessels by measuring the lung diffusing capacity (a breathing test) and exhaled Nitric Oxide (NO) (a substance in the body that relaxes or dilates blood vessels). We will also measure endothelial progenitor cells (cells from the bone marrow) from a blood sample; these cells are markers of measure of blood vessel formation and repair. We will also measure the activity of superoxide dismutase (a protein in cells that executes the breakdown of a free radical into oxygen and hydrogen peroxide) in the blood. In addition, we will measure levels of coenzyme Q-10 in the blood. Other markers of disease response to therapy will be done including physical exam, BNP level (a blood marker that correlates with heart function), 6-minute walk and echocardiography (ultrasound of the heart). A total of 60ml (5 tablespoons) of blood will be drawn at each visit.

Inclusion Criteria:

• Males and Females age equal to or greater than 18 not to exceed 65.
• Patients with PAH Class 1 (Venice 2003)
• PAH medications must not have changed for the last two months.
• Women of child-bearing age must use a double-barrier local contraception until completion of study.
• Subjects must demonstrate understanding of study and sign informed consent and have a reliable method of communication for contact and the ability to comply with the study requirements.

Exclusion Criteria:

• Participation in any other studies at the time of enrollment
• History of any significant illness within four weeks of starting Coenzyme Q-10
• Hepatic insufficiency (transaminase levels >4 fold the upper limit of normal or bilirubin >2 fold the upper limit of normal).
• Renal insufficiency (creatinine >2)
• Pregnancy,breast-feeding or lack of safe contraception.
• Acute heart failure
• Known allergy to the study drug or drugs similar to the study drug
• History of drug or alcohol abuse within last 12 months

The adverse event data was collected over each participants treatment period, up to three months.

Length of the trial and number of subjects enrolled were both study limitations.