PAHTCH Pulmonary Arterial Hypertension Treatment With Carvedilol for Heart Failure (Carvedilol)

Not Applicable

Completed

Brief Summary: Pulmonary arterial hypertension (PAH) is a progressive disease of the pulmonary vasculature leading to elevated pulmonary pressure and right ventricular (RV) dysfunction with heart failure. Measures of RV function are better predictors of mortality and long term outcomes than pulmonary vascular resistance. The interaction between RV function and the pulmonary circulation is not fully understood, but increased after load appears insufficient to explain right heart failure. Yet, all approved PAH therapies target vasodilation of the pulmonary vasculature to lower pressures

Detailed Description: Pulmonary arterial hypertension (PAH) is a serious condition characterized by endothelial dysfunction leading to pulmonary vascular constriction, smooth muscle and endothelial proliferation, and progressive right-sided heart failure. The severity of pulmonary hypertension is mostly determined by the response of the right ventricle (RV) to the increased afterload or pulmonary pressures, and RV failure is the leading cause of death in PAH. Most accepted therapies for PAH have been aimed at vasodilation of the pulmonary vasculature, and there has been little thought that PAH patients would benefit from traditional left heart failure treatments. A cornerstone therapy in left heart failure is £\]-adrenergic receptor blockade because of its ability to reverse cardiac remodeling and improve clinical outcomes, despite decades of concern regarding its propensity to exacerbate heart failure. It has been reported to reduce mortality by about 30% in patients, and while the precise mechanisms that contribute to its beneficial effects remain to be elucidated, there is evidence that patients with underlying contractile reserve (i.e., via recruitment of viable myocardium with £\]-adrenergic receptor stimulation) may experience greater recovery of their cardiac function. In a study using rats with pulmonary hypertension treated with £\] blocker, RV function improved, and maladaptive myocardial remodeling was prevented.

Recruitment & Eligibility

Inclusion Criteria

Men and women age 18 or older not greater than age 65 years
Diagnosis of pulmonary arterial hypertension class 1, 3, 4, 5 (Dana Point 2008)
NYHA (New York Health Association)/WHO (World Health Organization) Class I-III
PAH medications must have been initiated according to the latest consensus statement recommendations and remained stable for the last 30 days
Women of child-bearing age must use a double-barrier local contraception till completion of the study
Subjects must demonstrate understanding of the study, sign the informed consent, and have a reliable method of communication for contact and ability to comply with the study requirements

Exclusion Criteria

Participation in any other treatment studies during enrollment
Significant illness in the past 30 days requiring hospitalization
Hepatic insufficiency (transaminase levels > 4 fold the upper limit of normal or bilirubin > 2 fold the upper limit of normal),
History of HIV, Hepatitis B or C
Serum creatinine > 2.8 mg/dl
Pregnancy, breast-feeding, or lack of safe contraception
Acute decompensated heart failure within past 30 days
Known allergy or intolerance to carvedilol or other β blockers
Significant, persistent bradycardia (resting heart rate < 50 bpm) or hypotension (systolic blood pressure < 100 mmHg or mean blood pressure < 70 mmHg) at the time of enrollment
Second or third-degree AV (Atrial Ventricular) block without pacemaker
Use of CYP2D6 isoenzyme inhibitors (such as quinidine, fluoxetine, paroxetine, propafenone) which increase drug levels and result in greater vasodilating effects and hypotension
Use of hypotensive drugs that deplete catecholamines (such as reserpine and monoamine oxidase inhibitors) which may lead to greater signs of hypotension or bradycardia
Other medical and psychosocial conditions as determined by principal investigator deemed unsuitable for enrollment

Arm && Interventions

Group	Intervention	Description
Placebo Arm	placebo	Eligible subjects will receive open label carvedilol therapy at a dose 3.125 mg twice daily for one week. Subjects will be admitted overnight for the first-dose challenge of carvedilol. After one week run in phase, subjects will be placed on placebo. Subjects and Investigators will be blinded to the group assignment for the duration of the study.
Open Label Carvedilol	Carvedilol	Eligible subjects will receive open label carvedilol therapy at a dose 3.125 mg twice daily for one week. Subjects will be admitted overnight to the CRU (Clinical Research Unit) for the first-dose challenge of carvedilol. Subjects will take the medication for one week and at the end of one week, eligible subjects will be randomized to one of two groups (blinded). Group 1 will receive 3.125mg twice daily for six months.Group 2 will receive carvedilol in a dose escalation scheme. They will be given 3.125mg tablets to take twice daily for one week, followed by 6.25 mg twice daily for one week, followed by 12.5mg twice daily for one week with the option to increase to the max dose of 25mg twice daily for the remainder of the study.

Primary Outcome Measures

Name	Time	Method
Cardiac Glucose Uptake in FDG-PET (Fluorodeoxyglucose-Positron Emission Tomography)	6 months	We hypothesize that use of carvedilol in patients with PAH (Pulmonary Arterial Hypertension) will decrease the cardiac glucose utilization, and this will be measurable as a drop in fasting FDG-PET standardized uptake values of the heart at 6 months as compared to baseline

Secondary Outcome Measures

Name	Time	Method
Urinary cAMP (Cyclic Adenosine Monophosphate)/Creatinine	6 months	We hypothesize that use of carvedilol in patients with PAH will increase beta adrenergic receptor function and this will be measurable as an increase in cAMP measured in the urine at 6 months in participants in dose escalation carvedilol.
Beta-Adrenergic Receptor (Alprenolol Binding Assay)	6 months	We hypothesize that use of carvedilol in patients with PAH will increase beta- adrenergic receptor availability, and this will be measurable as a increase in alprenolol binding over time of drug use.