Effect of iNO in Patients With Submassive and Massive PE

This is a single center study to evaluate patients presenting with imaging confirmed intermediate/submassive or massive pulmonary embolism (PE). The investigators anticipate to enroll a total of 20-25 subjects at Ronald Reagan UCLA Medical Center.

After informed consent is obtained, the subject will proceed under one of two study intervention arms depending on his or her treatment plan. If the patient requires invasive treatment such as interventional thrombectomy or catheter-directed thrombolysis (CDT), the participant will be enrolled in the interventional radiology arm (invasive cohort). If the patient requires non-invasive treatment such as anticoagulation therapy, deep vein thrombosis (DVT) thrombectomy, or inferior vena cava (IVC) filter, the participant will be enrolled in the non-intervention arm (non-invasive cohort).

Interventional Radiology Arm (Invasive Cohort):

The following procedure will be performed:

Interventional radiology (IR) will perform a right heart catheterization (RHC) as part of a planned IR procedure. Patient arrives in the IR suite and is positioned flat with head of bed between flat and 45 degrees. O2 amount and modality, blood pressure, pressor name, dose, and rate will be recorded. If the patient is intubated, the sedation/analgesia drug name(s), dose(s), and rate(s) will be recorded. If the patient is not intubated, name and dose amount of sedation will be recorded. Arterial blood gas will be obtained if an A-line is placed.

Bedside apical 4 chamber view (RV:LV ratio) will be recorded using an ultrasound device, and noninvasive RV data will be obtained with Edwards ClearSight system and Edwards EV1000 clinical platform.

Edwards ClearSight system and Edwards EV1000 clinical platform is a finger probe worn with a supportive forearm strap. Hemodynamic measurements from the finger cuff will be recorded at intervals.

Novel non-invasive methods of estimating stroke volume and associated cardiac output have the potential to revolutionize PE risk stratification and care. Non-invasive blood pressure (NIBP) monitors can even measure stroke volume beat to beat, allowing for continuous evaluation of cardiac function. NIBP systems are typically composed of a finger cuff with an inflatable bladder, pressure sensors, and light sensors. An arterial pulse contour is formed using the volume clamp method of blood pressure measurement combined with calibration and brachial pressure reconstruction algorithms. The stroke volume with each heart beat can be estimated as the area under the systolic portion of the blood pressure curve divided by the afterload. A limitation of using NIBP monitors to measure stroke volume is their relative inaccuracy, as they are calculations of an indirect measurement. However, NIBP monitors¬ may improve clinical care of PE because they allow for assessment of dynamic cardiac changes in real time. Detection of worsening stroke volume in acute PE could inform providers of impending cardiac collapse, and improvement of stroke volume may function as a positive prognostic factor or marker of therapeutic success. Use of NIBP monitors during acute PE to identify clinically significant changes in cardiac function may advance both PE prognostication and management.