Pilot Study of Inhaled Nitric Oxide to Treat Pulmonary Insufficiency in Congenital Heart Disease

Study Overview
=================
Brief Summary
-----------------
Inhaled nitric oxide in patients with pulmonic valve insufficiency.

Detailed Description
-----------------
Pulmonic valve insufficiency (PI) is a well-defined problem after primary surgical repair of Tetralogy of Fallot (TOF). Though well-tolerated for years, long-term PI can lead to structural changes in the right ventricle, the sequelae of which include right heart failure, arrhythmia, and sudden cardiac death. The only current treatment for severe symptomatic PI is pulmonic valve replacement. We hypothesize that inhaled nitric oxide (iNO), a selective pulmonary vasodilator, can acutely decrease PI as assessed by cardiac magnetic resonance imaging (CMR). Methods: 22 consecutive patients with PI in the setting of corrected TOF or post pulmonic valve balloon valvuloplasty will undergo a clinically indicated CMR. Nitric oxide gas will be delivered via facemask through a specialized delivery device at 40ppm. After 5 minutes, flow velocity mapping and gradient echo sequences will be repeated to assess pulmonary regurgitant fraction, right ventricular volumes, and ejection fraction. Nitric oxide will be discontinued after acquisition of the last picture. Wilcoxon rank-sum for paired data will be used to assess effect of intervention. Significance: If decreasing pulmonary vascular resistance decreases PI, medical therapy with long-acting pulmonary vasodilators may be an attractive therapeutic option with the goal of delaying or even obviating pulmonic valve replacement.

Official Title
-----------------
Acute Effect of Inhaled Nitric Oxide on Pulmonary Insufficiency in Congenital Heart Disease

Conditions
-----------------
Pulmonary Insufficiency

Intervention / Treatment
-----------------
* Drug: iNO administered


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Known pulmonary insufficiency status Previous Tetralogy of Fallot repair or balloon valvuloplasty/surgical valvotomy for pulmonary stenosis Clinically indicated cardiac magnetic resonance imaging study Exclusion Criteria: Enrollment in another clinical trial Age less then 18 years Inability to provide informed consent Institutionalized individual Pregnant or lactating Serious claustrophobia Pacemaker/ICD Aneurysm clips Internal hardware Severe obesity (>350lbs) Residual ventricular septal defect History of methemoglobinemia History of blood dyscrasias Acute pulmonary infection Pulmonary edema Hypersensitivity to nitric oxide or any of its components Left ventricle dysfunction (EF<40%) Concurrent use of nitroglycerin or prilocaine

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: iNO administered<br>iNO administered at 40 ppm via a non-rebreather mask | Drug: iNO administered<br>* iNO at 40 ppm through a non-rebreather mask for 5 minutes<br>* Other names: Nitric Oxide;|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| pulmonary regurgitant volume and fraction | Aortic regurgitant fraction measured by CMR velocity flow mapping | Single time point |