Body Volume Regulation in Pulmonary Arterial Hypertension With Right Ventricular Failure

Secondary hyperaldosteronism and the non-osmotic release of arginine vasopressin (AVP) are the major factors in sodium and water retention in pulmonary arterial hypertension with right ventricular failure. Natriuretic doses of mineralocorticoid antagonist and aquaretic doses of V2 receptor antagonist will attenuate the sodium and water retention respectively, and be associated with clinical improvement.

Study Overview

• Status: Withdrawn
• Conditions: Pulmonary Hypertension; Right Heart Failure
• Intervention / Treatment: Drug: Spironolactone and conivaptan

Detailed Description

Much has been learned about the pathophysiological state that underlies the development of increased total body volume and edema in left ventricular failure. Very little, however, is known about the mechanism underlying systemic hypervolemia in patients with isolated right ventricular dysfunction. Patients with pulmonary arterial hypertension (PAH) represent a model of isolated right ventricular dysfunction in which these mechanisms may be elucidated. Aldosterone has now been shown to have many properties that are likely to be detrimental in congestive heart failure (CHF) and that are not shared by angiotensin II. Aldosterone blockade has been associated with improved mortality in patients with left ventricular failure, already receiving an angiotensin converting enzyme inhibitor. But its role in isolated right ventricular failure has not been elucidated. The plasma arginine vasopressin levels are disproportionately elevated for the degree of serum osmolarity in patients with heart failure and result in water retention and hyponatremia. Conivaptan, a vasopressin receptor antagonist, appears to reduce body weight and improve signs of left heart failure, though there is no study to evaluate its role in right ventricular failure with edema.

This study will examine the role of spironolactone and conivaptan in patients with right ventricular failure and pathophysiology of sodium and water retention in these patients.

• Study Type: Interventional
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Colorado
    • Denver, Colorado, United States, 80262
      • University of Colorado at Denver and Health Sciences Center General Clinical Research Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 75 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

1. Patients with World Health Organization (WHO) group 1 pulmonary arterial hypertension [51], excluding patients with portal hypertension, meeting the following hemodynamic parameters:

• Mean pulmonary artery pressure (mPAP) >35 mmHg at rest, and
• Pulmonary capillary wedge pressure (PCWP) <15 mmHg, and
• Pulmonary vascular resistance (PVR) >1.5 wood units, and 2. Age 18 to 75 years 3. Right ventricular failure defined by right atrial pressure >7 mmHg along with either dilated right ventricle, or absence of inferior vena cava collapse or BNP >100 pg/ml 4. Patients of childbearing age must be practicing effective birth control. 5. Normal left ventricular function as assessed by echocardiogram, multiple gated acquisition (MUGA) cardiac scan, or invasive left ventriculography.

Exclusion Criteria:

1. Group 2-5 pulmonary hypertension as defined by WHO.

• Pulmonary hypertension with left heart failure (as assessed by echocardiogram, multiple gated acquisition (MUGA) cardiac scan, or invasive left ventriculography).
• Pulmonary hypertension associated with lung disease and/or hypoxemia (e.g. chronic obstructive pulmonary disease, interstitial lung disease, sleep disordered breathing, chronic exposure to high altitude, alveolar hypoventilation syndrome.
• Pulmonary hypertension due to chronic thrombotic and/or embolic diseases
• Miscellaneous such as sarcoidosis, compression of pulmonary vessels by adenopathy, tumor 2. Systemic hypertension, defined as a systolic pressure >140 mmHg or a diastolic blood pressure >90 mmHg 3. Patients taking angiotensin converting enzyme (ACE) inhibitor or angiotensin receptor blockers (ARBs) 4. Pregnancy 5. Chronic kidney disease (serum creatinine > 2.5mg/dl, proteinuria >500 mg/day, hematuria) 6. Cirrhosis or portal hypertension 7. Inability to provide informed consent. 8. Allergy to conivaptan or spironolactone. 9. Active malignancy 10. Patients receiving spironolactone 11. Enrollment in other interventional studies. 12. Patients on Highly Active Antiretroviral Therapy (HAART)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
No Intervention: Usual care; Group II
Experimental: Spironolactone and conivaptan; Group I	Drug: Spironolactone and conivaptan; Tablet, 50 mg to 200 mg, daily, orally 20 mg intravenously one time over 30 minutes

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cross sectional study	Correlation between severity of pulmonary hypertension and neurohumoral activation, Regional Blood Flow (RBF) & Transcatheter Pulmonary Valve (TPV). Acute study:electrolyte-free water and sodium excretion. Cohort Study: Composite of Cardiac index (CI),brain natriuretic peptide (BNP) and Right Atrial Pressure (RAP)	18 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cross-sectional Study	Correlations between mean pulmonary artery pressure, pulmonary vascular resistance; and neurohumoral activation, glomerular filtration rate (GFR) and Transcatheter Pulmonary Valve (TPV). Acute study:correlation between response to drug and severity of disease.	18 months

Collaborators and Investigators

• Sponsor: University of Colorado, Denver
• Investigators: Principal Investigator: Shweta Bansal, MD, UCHSC

Study record dates

Study Major Dates

• Study Start: January 1, 2009
• Primary Completion (Actual): July 1, 2010
• Study Completion (Actual): December 1, 2010

Study Registration Dates

• First Submitted: December 18, 2008
• First Submitted That Met QC Criteria: December 18, 2008
• First Posted (Estimate): December 19, 2008

Study Record Updates

• Last Update Posted (Estimate): January 28, 2013
• Last Update Submitted That Met QC Criteria: January 25, 2013
• Last Verified: January 1, 2013

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Cardiovascular Diseases; Vascular Diseases; Respiratory Tract Diseases; Lung Diseases; Hypertension; Pulmonary Arterial Hypertension; Hypertension, Pulmonary; Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Hormones, Hormone Substitutes, and Hormone Antagonists; Natriuretic Agents; Diuretics; Hormone Antagonists; Mineralocorticoid Receptor Antagonists; Diuretics, Potassium Sparing; Antidiuretic Hormone Receptor Antagonists; Spironolactone; Conivaptan
• Other Study ID Numbers: 07-1022