Memos

Editor's Memo

Deborah Jo Levine, MD

Professor of Medicine, Pulmonary and Critical Care, Medical Director Lung Transplantation, Director of Pulmonary Hypertension, University of Texas Health Science Center, San Antonio,San Antonio, TX

It is a great pleasure to introduce the newest issue of Advances in Pulmonary Hypertension (PH). During these challenging times when clinicians are combatting the COVID-19 pandemic while keeping their own patients safe, we are grateful to the Guest Editor and authors for taking the time to submit this eloquent update on techniques we are using in the catheterization lab to diagnose and manage patients with PH.

I would like to congratulate Dr Richard A. Krasuski, our guest editor of this issue. Rich is a Professor of Medicine and Director of Adult Congenital Disease and Pulmonary Hypertension at Duke University. Throughout his career, Rich has been at the forefront of advancing techniques in the cath lab for patients with PH. He proposed the idea for this issue of updating our community on where we are now and we are going with “New Invasive Technologies” in the cath lab for PH and right heart dysfunction.

Dr Eric Bonno and colleagues have written an excellent and thorough discussion on right heart catheterization (RHC). In this first article, they educate us not only on invasive hemodynamics and waveform interpretation, but also on what is needed technically to perform the procedure. They also go into detail on specific studies performed during the RHC (ie, fluid challenge, cardiac output reading, vasodilator testing, exercise), pointing out important features that are required for accuracy.

Drs Julie Wacker and Maurice Beghetti do an excellent job discussing the complex topic of pulmonary arterial hypertension (PAH) and shunts. They first go through the pathophysiology and the etiologies of shunt physiology and then discuss multiple areas of management. This comprehensive article covers medical management as well as how to manage a shunt in the cath lab or the operating room and when each is recommended. They also discuss when a shunt may be created in the management of severe PAH (atrial septostomy or reversed Potts shunt).

Dr Takeshi Ogo scripted a complete review and update on balloon pulmonary angioplasty for chronic thromboembolic PH. He goes through the evolution, history, criteria, and the procedure itself. He also discusses some of the complicated issues of outcomes and its future.

We also have a thought-provoking roundtable with a group of experts deliberating the benefits and outcomes of new invasive techniques in PH. Dr Krasuski moderates this group that includes Drs Jamil Aboulhosn, Raymond Benza, and J. Eduardo Rame.

To round out the issue, in our Ask the Expert section, Drs Allison L. Tsao and Alexander Opotowsky review the role of devices (percutaneous or surgically implanted right ventricular assist devices) in patients with PAH. And in our PH Grand Rounds section, Dr Amy Goodrich-Harris and colleagues analyze a case of a giant pulmonary artery aneurysm and severe multi-factorial PH. This case brings up several issues that are elucidated with a literature review and teaching points.

We hope you enjoy and learn from this excellent reference on current and future tools for both the diagnosis as well as the management of PH and right heart failure.

And to everyone during this time—be safe and stay well.

Guest Editor's Memo

Richard A. Krasuski, MD

Professor of Medicine, Duke University School of Medicine, Durham, NC

In 1956, the Nobel Prize in Physiology or Medicine was shared by three individuals who helped shape the field of invasive hemodynamics.1 Werner Forssmann was a rebellious first-year medical student who in 1929 inserted a urinary catheter into his own antecubital vein and utilized radiography to document the event,2 while Dickinson Richards and Andre Cournard started the first hemodynamics laboratory at Columbia University, where they perfected techniques of right heart pressure assessment, first in animals and then in humans in the 1930s and 40s.3 These pioneers set the scene for David Dresdale, who in 1950 found elevated pulmonary pressures in the absence of left heart pathology in three patients with “primary pulmonary hypertension” 4 and later (in 1954) performed the first successful vasodilator challenge in this patient population.5 Many advances in the fields of coronary, structural, and congenital heart intervention have since followed; and the modern-day catheterization laboratory is a potpourri of hemodynamics, advanced and integrated imaging, as well as novel interventional procedures. In the spirit of these tremendous innovations, we have devoted this issue of Advances in Pulmonary Hypertension to “New Invasive Technologies.”

In the first article Dr Ryan Tedford and his colleagues walk us through the features of a standard hemodynamic assessment in a patient with pulmonary hypertension (PH). As noted, preparation is the key to successful data collection and appropriate interpretation. Diagnostic and prognostic information can be gleaned from simple measures, but provocations such as exercise, volume loading, and vasodilator administration can further ensure appropriate diagnosis and subsequent therapy. Drs Maurice Beghetti and Julie Wacker then discuss shunt physiology and how it is altered by changes in the pulmonary vascular resistance. It is important to recognize that a procedure as simple as closure of a secundum atrial septal defect, now standardly performed under minimal conscious sedation and echo and fluoroscopic guidance, may have potential detrimental effects depending on the clinical scenario. In fact, for some patients with advanced degrees of PH, the opposite procedure (creation of such a shunt), either at the atrial level or further downstream, may have beneficial effects on maintaining cardiac output, albeit at the expense of systemic cyanosis. Dr Takeshi Ogo follows with a review of the current status of balloon pulmonary angioplasty (BPA) for inoperable chronic thromboembolic pulmonary hypertension. Adapting techniques first developed in congenital heart patients, BPA has demonstrated significant hemodynamic and clinical improvements with an acceptable clinical risk.6

A significant remaining challenge in the management of advanced PH is how to support the failing right ventricle. Drs Alexander Opotowsky and Allison Tsao review for us currently available devices and their inherent limitations.

Finally, our Roundtable discussion covers the newest technologies we now have available and how some of these advances are taking the hemodynamic laboratory outside of the confines of the catheterization suite. It is exciting to think of how far we have come over the last century, but also daunting to think of how much further we still need to go. I hope you all enjoy this issue as much as I have enjoyed putting it together.