Real-world scenarios show complexity of initial and ongoing PAH treatment decisions

With more than a dozen treatment options available for pulmonary arterial hypertension (PAH), it can be challenging to select the appropriate initial therapies and determine ongoing approaches for each patient.

The CHEST 2022 interactive session, Pulmonary Arterial Hypertension: Therapeutic Dilemmas, on Sunday, October 16, presented real-world scenarios and research data to help attendees cut through that confusion. Three experts discussed choosing appropriate starting therapies, what route to use when starting prostacyclins as a third drug, and how to develop a strategy to transition between multiple therapies.

Paresh C. Giri, MD, FCCP
Paresh C. Giri, MD, FCCP

Paresh C. Giri, MD, FCCP, associate professor of medicine and director of the pulmonary hypertension regional clinical program at Loma Linda University Health, opened the session by exploring the question of whether to start single, dual, or triple therapy for patients with severe PAH.

The first step to selecting therapy is risk assessment, which requires assessment of multiple parameters, Dr. Giri said.

Despite specific differences between established risk scores, all patients were grouped into risk categories based on 1-year mortality risk: low risk (<5%), intermediate risk (5%-10%), and high risk (>10%). Therapy is often selected based on the risk of mortality at baseline and the risk of mortality after therapy.

There are currently 14 Food and Drug Administration-approved therapies to choose from, Dr. Giri said, and there is no one dominant treatment pathway for PAH.

Monotherapy is often reserved for use in select low-risk patients, he said, while dual therapy is the appropriate approach for the majority of patients with low and intermediate risk. Triple therapy, including intravenous (IV)/subcutaneous prostacyclin, is reserved for patients that are high-risk.

However, he noted that the tools used to assess risk may need refinement. Currently, about 70% of patients fall into the intermediate category. There are a few patients at the high end of intermediate that could benefit from more aggressive therapy. Further breakdown of the categories into intermediate-high and intermediate-low may be beneficial.

“The goal is to attain and maintain low-risk status,” he concluded.

Jean M. Elwing, MD, FCCP
Jean M. Elwing, MD, FCCP

Jean M. Elwing, MD, FCCP, professor of medicine and director of the pulmonary hypertension program at the University of Cincinnati, followed with a further examination of when to use triple therapy and how to do it—specifically, whether to use enteral, inhaled, or parenteral routes when starting prostacyclins.

When it comes to prostacyclin pathway therapy options, it’s good to have so many choices, Dr. Elwing said, but clinicians must know the how, when, and why of these medications. Importantly, she said, the patient also has to agree.

In a case presentation, Dr. Elwing walked through the evolving risk assessment and therapy decision-making process with an intermediate-risk patient who started on combination therapy but worsened over time. Dr. Elwing detailed step-by-step conversations with the patient where they considered the different pathways for a third drug. After deciding to go with an oral prostacyclin receptor agonist, the patient worsened further to high risk. After further discussions, and a switch to an IV prostacyclin, the patient eventually achieved low-risk status.

“Some of it is personal choice, but a lot of it is us interacting with the patient and taking the time really to show them how these medications can have a positive effect on their outcomes,” Dr. Elwing said.

Ronald J. Oudiz, MD, FCCP
Ronald J. Oudiz, MD, FCCP

Finally, Ronald J. Oudiz, MD, FCCP, professor of medicine at the David Geffen School of Medicine at UCLA and director of the Liu Center for Pulmonary Hypertension and chief of the cardiology division at Harbor-UCLA Medical Center, closed the session by exploring transitioning between therapies.

Some patients may need to transition therapies because of drug interactions, Dr. Oudiz said, while others may transition because of tolerability issues. With the use of pumps, there are often quality-of-life issues related to the pump itself and the catheter, he said. These can include recurring or life-threatening infections, catheter integrity, site pain, and more. Another common reason for transition is patient request. Clinicians may see patients doing well on parenteral therapy who then ask if they might be able to switch to oral therapies. Finally, one of the most important reasons why a transition may occur is in an attempt to increase treatment potency.

Dr. Oudiz discussed many of the intricacies of transitioning patients from one treatment to another, including from one endothelin receptor antagonist (ERA) to another ERA, from parenteral to inhaled prostanoids, and so on.

“The how and why of transitioning can be incredibly variable and the individual need for that patient really needs to be weighed carefully,” Dr. Oudiz said.

He also emphasized that these transitions should be done in an expert center. This means a center that has a lot of patients with PAH and knows how to troubleshoot the risks and benefits when advising patients, as the transition from parenteral prostanoids can be dangerous even in the best of hands, Dr. Oudiz said.

This session was supported by an educational grant from Merck Sharp & Dohme, LLC and Bayer Pharmaceuticals.

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