The Medical Encyclopedia defines a systemic disease as an entity affecting the entire body, rather than a single organ or body part. So, is PAH, the disease of “high blood pressure in the lungs”, as the lay people call it, a systemic disease? I would argue, yes! First of all, PAH is part of several systemic disorders and what happens in the lungs happens also in other parts of the body. This argument is easily won when we think of systemic sclerosis, but not only. Second, PAH is a systemic disease, much like systemic hypertension. Even in its purest form, the idiopathic or hereditary PAH, the rest of the body is affected when various organs begin suffering from inadequate perfusion, initially with exertion, then even at rest. Third, as we begin to end the COVID-19 pandemic, let’s not forget about the other, more persistent, duplicitous pandemic, obesity, a systemic disease that also exerts its toxic effects on the pulmonary vasculature.

In this issue of Advances we address exactly these aspects of pulmonary vascular disease. Drs. Rahul Argula and Samuel Friedman from the Medical University of South Carolina provide a thorough, nonetheless very practical, overview of the various forms of SSc associated PH and the challenges caused by overlapping forms. They highlight advances in the screening, therapeutic management and risk stratification strategies for the various forms of PH. Lastly, they touch upon the more novel approaches, involving immunomodulatory treatments that are being currently investigated.

I teamed up with my young PH star from Tufts Medical Center, Dr. Divya Menon, to discuss a topic that is often forgotten, both to diagnose and to treat: PH in hematologic disorders. We focused on two main entities: myelodysplastic syndromes and hemolytic anemias.

The impact of obesity on PH (and vice versa) was examined by Drs. Anna Hemnes from Vanderbilt University and Debbie Levine from University of Texas Health Science Center who, very elegantly, explained the complex connections between the metabolic derangements driven by obesity and its effects on the lung vasculature. But what can we do when there is no “magic pill” to make you lose weight? The PHPN corner, led by Claire Parker from Vanderbilt University and authors Ai Jin Lee, Rebecca Alonzo, Charlotte Lipsky, Yessenia I. Ortega, Shannon A. Salveson, and Kathy McCloy, offers practical approaches to wiser and healthier nutrition and exercise for our PH patients, utilizing activity devices and friendly encouragements.

Lastly, I joined forces with Karen Fagan from University of South Alabama, Rod Oudiz from UCLA Medical Center, Panagis Galiatsatos from Johns Hopkins University, and my colleague from Tufts Medical Center, Hap Farber, to talk in a round table about our experiences during the pandemic. All experienced clinicians and PH specialists that worked assiduously in the front line for the past year and a half to battle our common enemy, SARS-CoV19, we shared thoughts on how COVID-19 affected our PH patients and what the measures were to ensure a safe environment and clinical practice from a distance, utilizing virtual visits. We conveyed our surprise that very few PH patients developed severe infection and praised our patients for their sensible approach to a potentially devastating disease.

I thank all the authors for their willingness to contribute to this issue and the Advances staff for their hard work, dedication, and enthusiasm. I hope you will enjoy reading it and that it will make you think more globally about PH, as part of the body and the environment.

Dr. Ioana R. Preston

Associate Professor of Medicine

Tufts University School of Medicine

Director, PH Center

Tufts Medical Center

Boston, MA