PAH Prognosis

Dr. Raymond Benza:

And Val, we know that our risk calculation needs to be performed to determine a patient's initial therapy regimen. After your patient begins their initial therapy, when are you performing risk calculations to assess whether they're meeting their treatment goals? And does this change based on the type of patient that you're looking at?

Dr. Vallerie McLaughlin:

Yeah, Ray, that's a really important question. I think we have spent a lot of time over the years focusing on what's the right initial treatment, and obviously that's a very important question. But I think what's even the more important question is, where do we get with that initial treatment? What is that patient's risk? And do we need to do more?

I'll tell you, patients often ask me when they're diagnosed, "What's my prognosis? How long do I have to live?" And I tell you, I don't even want to answer that question at the time of diagnosis anymore because what's more important than what the risk status is at the time of diagnosis, is where they get in terms of their risk status on therapy.

So, that initial treatment choice is important, but it needs to be followed up. We need to reassess them on therapy to see if they're meeting the criteria for the low-risk status.

We tend to reassess our patients within about 3 months. We may call them over the phone before that 3-month visit, to make sure they're tolerating their therapy, and they're sticking with it, and that their side effects are well controlled.

But we'll generally bring pretty much all of our patients back to clinic within 3 months and reassess their risk, at the very least the assessment of Functional Class, the physical exam, the hall walk, biomarkers, often imaging as well. And we'll do an objective risk score, as we've talked about.

There are many from which to choose. REVEAL, which you've been so instrumentally involved in, Ray, the French, either invasive or noninvasive, or the ERS/ESC approach, but you need to do some objective assessment and determine whether or not the patient's at low-risk status. And if they're not at low-risk status, then you need to escalate therapy. And there are obviously many choices to do that.

Dr. Raymond Benza:

Yeah, I think you brought up some very important points. The initial diagnosis and risk stratification really sets the tenor of that initial therapy, but it's really the follow-up assessment that really tells you what that trajectory is going to be and if that patient's moving in the right direction with that initial therapy.

So, I agree that second assessment is so important and having that done at least by the 3-month mark, after you're starting a therapy, I think is a really appropriate way to do it. So thanks for highlighting that.

So, when you see a patient who's currently taking 2 medications, for example, 1 covering the ERA pathway and 1 covering the NO pathway, and currently they're still at intermediate risk, how long would you wait before escalating their therapy to include maybe a prostacyclin-class therapy?

Dr. Vallerie McLaughlin:

Well, Ray, I think that's an important question. If we're doing a 3-month risk assessment, and they are at intermediate risk on an ERA and PDE5, it's time to escalate. I would do it at that 3-month point. I don't think that waiting much longer is really going to benefit the patient. And, in fact, it may harm the patient.

I think the key there is intermediate risk. Intermediate risk, to me, is such a wide range. I hate to get too technical but, in my mind, there's low intermediate. There's high intermediate. I look at these patients in very different ways, and I know you do too. And the REVEAL risk score kind of delineates this a lot as well.

So, I definitely think at 3 months, if we are still in intermediate risk, we need to do something else. And often that is add a prostacyclin pathway agent, if they are on an ERA and a PDE5. But then there's the opportunity to tease things out a little bit more, to determine how that should be done.

Dr. Raymond Benza:

Yeah, I think that's a really important point, to really know where they fit in that intermediate range, because it is really a very big gray area for us. And I think that's where a lot of our contemporary risk stratification systems seem to lack some of their discrimination is in that category, combining our risk stratification algorithms with additional testing, like imaging, is ultimately important, really deciding how aggressive that third category of drug is. But I agree with you 100%. Don't leave people in intermediate risk, if you have additional medications that you can use to drive them to that lower-risk status. That's really important.