PAH Risk Scores vs Right Heart Function: Interpreting Echo Beyond Pressure

This episode, "PAH Risk Scores vs Right Heart Function: Interpreting Echo Beyond Pressure," brings the panel to the cases where formal scores and clinical reality diverge.

Dr. Channick illustrates the limits of risk scores with two contrasting patients. The first is an 82-year-old, five-foot-one woman with scleroderma whose 440-meter walk target is 100 meters above her age-predicted distance and who is functional class III from her rheumatologic disease. Her right ventricular size and function are normal on echo, so no added medication will move her to low risk. The second is a healthy, six-foot-one man with heritable PAH who walks 470 meters against a predicted 700, so he scores low risk even though his right ventricle is large and dysfunctional.

Dr. Vaidya describes a similar woman with connective tissue disease who brought a note from her local pulmonologist asking about additional therapy. Her normal right ventricular size and function and a pulmonary vascular resistance of 2.4 gave both clinicians objective reassurance.

Dr. Channick notes that the echo pressure estimate is the least important parameter even though patients ask only about it. Dr. Vaidya explains that it is truly an estimate that may be off by 10 mmHg above or below half the time. It also cannot show whether the pressure comes from pulmonary vascular resistance or left heart congestion. It helps bring patients into the diagnostic pathway, but afterward the focus shifts to the size, structure, function, and performance of the right heart.

Dr. McLaughlin adds that community echo reports often give only the pressure and a qualitative impression of right ventricular function, without S prime, strain, or fractional area change. Dr. Kim reminds learners that severity depends on context, since right ventricular reserve matters more than pressure after diagnosis. A borderline pressure with normal left heart features and a dilating right ventricle should prompt a call to an expert center.

Up next, in "Escalating PAH Therapy: Setting Expectations and Choosing the Next Step," the panel discusses the difficult conversation about adding therapy and the choice between switching and escalating.