PINOT NOIR: Pulmonic INsufficiency imprOvemenT with Nitric Oxide Inhalational Response

Abstract

BackgroundTetralogy of Fallot (TOF) repair and pulmonary valvotomy for pulmonary stenosis (PS) lead to progressive pulmonary insufficiency (PI), right ventricular enlargement and dysfunction. This study assessed whether pulmonary regurgitant fraction measured by cardiovascular magnetic resonance (CMR) could be reduced with inhaled nitric oxide (iNO).MethodsPatients with at least moderate PI by echocardiography undergoing clinically indicated CMR were prospectively enrolled. Patients with residual hemodynamic lesions were excluded. Ventricular volume and blood flow sequences were obtained at baseline and during administration of 40 ppm iNO.ResultsSixteen patients (11 with repaired TOF and 5 with repaired PS) completed the protocol with adequate data for analysis. The median age [range] was 35 [19–46] years, BMI was 26 ± 5 kg/m2 (mean ± SD), 50% were women and 75% were in NYHA class I. Right ventricular end diastolic volume index for the cohort was 157 ± 33 mL/m2, end systolic volume index was 93 ± 20 mL/m2 and right ventricular ejection fraction was 40 ± 6%. Baseline pulmonary regurgitant volume was 45 ± 25 mL/beat and regurgitant fraction was 35 ± 16%. During administration of iNO, regurgitant volume was reduced by an average of 6 ± 9% (p=0.01) and regurgitant fraction was reduced by an average of 5 ± 8% (p=0.02). No significant changes were observed in ventricular indices for either the left or right ventricle.ConclusioniNO was successfully administered during CMR acquisition and appears to reduce regurgitant fraction in patients with at least moderate PI suggesting a potential role for selective pulmonary vasodilator therapy in these patients.Trials registrationClinicalTrials.gov, NCT00543933

Rationale for Use of an FDA-Cleared Delivery System for Administration of Inhaled Nitric Oxide in Patients Undergoing Magnetic Resonance Imaging

“…Results from this single-patient study prompted the same investigators to conduct a larger study in which cardiac MRI was performed at 1.5 Tesla (Magnetom Avanto; Siemens Medical Systems, Erlangen, Germany) while delivering continuous iNO using their modified device in 16 patients with pulmonary valve insufficiency and repaired tetralogy of Fallot or pulmonary stenosis. 23 In this study, all right and left ventricular volumetric measurements remained unchanged when using the modified device, and no significant changes in aortic flow parameters were observed. NO 2 levels were not evaluated.…”

Delivery of Inhaled Nitric Oxide During MRI to Ventilated Neonates and Infants

“…There are a small number of papers describing the temporary trialing of NO administered via face mask while performing cardiac [13][14][15] or pulmonary 16 MRI for investigative purposes, but we found none that describe the particular method and application we have used, whereby a ventilated neonate or child from a neonatal or pediatric ICU who is already receiving INO can be transported to and from MRI and have a MRI while continuing to receive INO therapy using the same system. We have demonstrated a novel system capable of doing this, a system that can generate a range of clinically relevant NO concentrations while providing adequate ventilation for patients up to $ 20 kg.…”

Review of Journal of Cardiovascular Magnetic Resonance 2014

“…CMR of congenital heart disease is well established, although high quality acquisition and interpretation require training [ 1 ]. CMR is used in fetuses, [ 2 , 3 ] children, [ 4 ] and adults, [ 5 , 6 ] often as a complement to echocardiography, to avoid imaging with ionising radiation, and reduce the need for invasive diagnostic cardiac catheterisation [ 7 ]. CMR has a proven role in idiopathic pulmonary arterial hypertension and its potential utility in other forms of pulmonary arterial hypertension is under study.…”